From 7915725847a2ff1e7c0d5ddf651f64ecb1e90fc0 Mon Sep 17 00:00:00 2001
From: brotherstone97 <brotherstone97@gmail.com>
Date: Sun, 16 Apr 2023 23:44:59 +0900
Subject: [PATCH 01/18] solve practice1

---
 .gitignore                               |   3 +
 build.gradle                             |  19 ++
 gradlew                                  | 234 +++++++++++++++++++++++
 gradlew.bat                              |  89 +++++++++
 settings.gradle                          |   2 +
 src/main/java/practice1/AuthMethod.java  |   8 +
 src/main/java/practice1/CompanyName.java |   7 +
 src/main/java/practice1/Electronic.java  |  88 +++++++++
 src/main/java/practice1/User.java        | 101 ++++++++++
 9 files changed, 551 insertions(+)
 create mode 100644 .gitignore
 create mode 100644 build.gradle
 create mode 100644 gradlew
 create mode 100644 gradlew.bat
 create mode 100644 settings.gradle
 create mode 100644 src/main/java/practice1/AuthMethod.java
 create mode 100644 src/main/java/practice1/CompanyName.java
 create mode 100644 src/main/java/practice1/Electronic.java
 create mode 100644 src/main/java/practice1/User.java

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..6db4f2e
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,3 @@
+.gradle
+.idea
+gradle
diff --git a/build.gradle b/build.gradle
new file mode 100644
index 0000000..3cae2d7
--- /dev/null
+++ b/build.gradle
@@ -0,0 +1,19 @@
+plugins {
+    id 'java'
+}
+
+group 'org.example'
+version '1.0-SNAPSHOT'
+
+repositories {
+    mavenCentral()
+}
+
+dependencies {
+    testImplementation 'org.junit.jupiter:junit-jupiter-api:5.8.1'
+    testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine:5.8.1'
+}
+
+test {
+    useJUnitPlatform()
+}
\ No newline at end of file
diff --git a/gradlew b/gradlew
new file mode 100644
index 0000000..1b6c787
--- /dev/null
+++ b/gradlew
@@ -0,0 +1,234 @@
+#!/bin/sh
+
+#
+# Copyright © 2015-2021 the original authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+##############################################################################
+#
+#   Gradle start up script for POSIX generated by Gradle.
+#
+#   Important for running:
+#
+#   (1) You need a POSIX-compliant shell to run this script. If your /bin/sh is
+#       noncompliant, but you have some other compliant shell such as ksh or
+#       bash, then to run this script, type that shell name before the whole
+#       command line, like:
+#
+#           ksh Gradle
+#
+#       Busybox and similar reduced shells will NOT work, because this script
+#       requires all of these POSIX shell features:
+#         * functions;
+#         * expansions «$var», «${var}», «${var:-default}», «${var+SET}»,
+#           «${var#prefix}», «${var%suffix}», and «$( cmd )»;
+#         * compound commands having a testable exit status, especially «case»;
+#         * various built-in commands including «command», «set», and «ulimit».
+#
+#   Important for patching:
+#
+#   (2) This script targets any POSIX shell, so it avoids extensions provided
+#       by Bash, Ksh, etc; in particular arrays are avoided.
+#
+#       The "traditional" practice of packing multiple parameters into a
+#       space-separated string is a well documented source of bugs and security
+#       problems, so this is (mostly) avoided, by progressively accumulating
+#       options in "$@", and eventually passing that to Java.
+#
+#       Where the inherited environment variables (DEFAULT_JVM_OPTS, JAVA_OPTS,
+#       and GRADLE_OPTS) rely on word-splitting, this is performed explicitly;
+#       see the in-line comments for details.
+#
+#       There are tweaks for specific operating systems such as AIX, CygWin,
+#       Darwin, MinGW, and NonStop.
+#
+#   (3) This script is generated from the Groovy template
+#       https://github.com/gradle/gradle/blob/master/subprojects/plugins/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
+#       within the Gradle project.
+#
+#       You can find Gradle at https://github.com/gradle/gradle/.
+#
+##############################################################################
+
+# Attempt to set APP_HOME
+
+# Resolve links: $0 may be a link
+app_path=$0
+
+# Need this for daisy-chained symlinks.
+while
+    APP_HOME=${app_path%"${app_path##*/}"}  # leaves a trailing /; empty if no leading path
+    [ -h "$app_path" ]
+do
+    ls=$( ls -ld "$app_path" )
+    link=${ls#*' -> '}
+    case $link in             #(
+      /*)   app_path=$link ;; #(
+      *)    app_path=$APP_HOME$link ;;
+    esac
+done
+
+APP_HOME=$( cd "${APP_HOME:-./}" && pwd -P ) || exit
+
+APP_NAME="Gradle"
+APP_BASE_NAME=${0##*/}
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD=maximum
+
+warn () {
+    echo "$*"
+} >&2
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+} >&2
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "$( uname )" in                #(
+  CYGWIN* )         cygwin=true  ;; #(
+  Darwin* )         darwin=true  ;; #(
+  MSYS* | MINGW* )  msys=true    ;; #(
+  NONSTOP* )        nonstop=true ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD=$JAVA_HOME/jre/sh/java
+    else
+        JAVACMD=$JAVA_HOME/bin/java
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD=java
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
+    case $MAX_FD in #(
+      max*)
+        MAX_FD=$( ulimit -H -n ) ||
+            warn "Could not query maximum file descriptor limit"
+    esac
+    case $MAX_FD in  #(
+      '' | soft) :;; #(
+      *)
+        ulimit -n "$MAX_FD" ||
+            warn "Could not set maximum file descriptor limit to $MAX_FD"
+    esac
+fi
+
+# Collect all arguments for the java command, stacking in reverse order:
+#   * args from the command line
+#   * the main class name
+#   * -classpath
+#   * -D...appname settings
+#   * --module-path (only if needed)
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and GRADLE_OPTS environment variables.
+
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if "$cygwin" || "$msys" ; then
+    APP_HOME=$( cygpath --path --mixed "$APP_HOME" )
+    CLASSPATH=$( cygpath --path --mixed "$CLASSPATH" )
+
+    JAVACMD=$( cygpath --unix "$JAVACMD" )
+
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    for arg do
+        if
+            case $arg in                                #(
+              -*)   false ;;                            # don't mess with options #(
+              /?*)  t=${arg#/} t=/${t%%/*}              # looks like a POSIX filepath
+                    [ -e "$t" ] ;;                      #(
+              *)    false ;;
+            esac
+        then
+            arg=$( cygpath --path --ignore --mixed "$arg" )
+        fi
+        # Roll the args list around exactly as many times as the number of
+        # args, so each arg winds up back in the position where it started, but
+        # possibly modified.
+        #
+        # NB: a `for` loop captures its iteration list before it begins, so
+        # changing the positional parameters here affects neither the number of
+        # iterations, nor the values presented in `arg`.
+        shift                   # remove old arg
+        set -- "$@" "$arg"      # push replacement arg
+    done
+fi
+
+# Collect all arguments for the java command;
+#   * $DEFAULT_JVM_OPTS, $JAVA_OPTS, and $GRADLE_OPTS can contain fragments of
+#     shell script including quotes and variable substitutions, so put them in
+#     double quotes to make sure that they get re-expanded; and
+#   * put everything else in single quotes, so that it's not re-expanded.
+
+set -- \
+        "-Dorg.gradle.appname=$APP_BASE_NAME" \
+        -classpath "$CLASSPATH" \
+        org.gradle.wrapper.GradleWrapperMain \
+        "$@"
+
+# Use "xargs" to parse quoted args.
+#
+# With -n1 it outputs one arg per line, with the quotes and backslashes removed.
+#
+# In Bash we could simply go:
+#
+#   readarray ARGS < <( xargs -n1 <<<"$var" ) &&
+#   set -- "${ARGS[@]}" "$@"
+#
+# but POSIX shell has neither arrays nor command substitution, so instead we
+# post-process each arg (as a line of input to sed) to backslash-escape any
+# character that might be a shell metacharacter, then use eval to reverse
+# that process (while maintaining the separation between arguments), and wrap
+# the whole thing up as a single "set" statement.
+#
+# This will of course break if any of these variables contains a newline or
+# an unmatched quote.
+#
+
+eval "set -- $(
+        printf '%s\n' "$DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS" |
+        xargs -n1 |
+        sed ' s~[^-[:alnum:]+,./:=@_]~\\&~g; ' |
+        tr '\n' ' '
+    )" '"$@"'
+
+exec "$JAVACMD" "$@"
diff --git a/gradlew.bat b/gradlew.bat
new file mode 100644
index 0000000..107acd3
--- /dev/null
+++ b/gradlew.bat
@@ -0,0 +1,89 @@
+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem You may obtain a copy of the License at
+@rem
+@rem      https://www.apache.org/licenses/LICENSE-2.0
+@rem
+@rem Unless required by applicable law or agreed to in writing, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Resolve any "." and ".." in APP_HOME to make it shorter.
+for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto execute
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto execute
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %*
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega
diff --git a/settings.gradle b/settings.gradle
new file mode 100644
index 0000000..af7740e
--- /dev/null
+++ b/settings.gradle
@@ -0,0 +1,2 @@
+rootProject.name = 'KDTBE5_Java_Assignment3'
+
diff --git a/src/main/java/practice1/AuthMethod.java b/src/main/java/practice1/AuthMethod.java
new file mode 100644
index 0000000..99cec3d
--- /dev/null
+++ b/src/main/java/practice1/AuthMethod.java
@@ -0,0 +1,8 @@
+package practice1;
+
+public enum AuthMethod {
+    PIN,
+    PATTERN,
+    FACE_ID,
+    FINGERPRINT,
+}
diff --git a/src/main/java/practice1/CompanyName.java b/src/main/java/practice1/CompanyName.java
new file mode 100644
index 0000000..148f91e
--- /dev/null
+++ b/src/main/java/practice1/CompanyName.java
@@ -0,0 +1,7 @@
+package practice1;
+
+public enum CompanyName {
+    SAMSUNG,
+    LG,
+    APPLE,
+}
diff --git a/src/main/java/practice1/Electronic.java b/src/main/java/practice1/Electronic.java
new file mode 100644
index 0000000..1356d07
--- /dev/null
+++ b/src/main/java/practice1/Electronic.java
@@ -0,0 +1,88 @@
+package practice1;
+
+import java.time.LocalDate;
+import java.util.Arrays;
+import java.util.Objects;
+
+public class Electronic {
+    private Long productNo;
+    private String modelName;
+    private CompanyName companyName;
+    private LocalDate dateOfMade;
+    private AuthMethod[] authMethod;
+
+    public Electronic(Long productNo, String modelName, CompanyName companyName, LocalDate dateOfMade, AuthMethod[] authMethod) {
+        this.productNo = productNo;
+        this.modelName = modelName;
+        this.companyName = companyName;
+        this.dateOfMade = dateOfMade;
+        this.authMethod = authMethod;
+    }
+
+    public Long getProductNo() {
+        return productNo;
+    }
+
+    public void setProductNo(Long productNo) {
+        this.productNo = productNo;
+    }
+
+    public String getModelName() {
+        return modelName;
+    }
+
+    public void setModelName(String modelName) {
+        this.modelName = modelName;
+    }
+
+    public CompanyName getCompanyName() {
+        return companyName;
+    }
+
+    public void setCompanyName(CompanyName companyName) {
+        this.companyName = companyName;
+    }
+
+    public LocalDate getDateOfMade() {
+        return dateOfMade;
+    }
+
+    public void setDateOfMade(LocalDate dateOfMade) {
+        this.dateOfMade = dateOfMade;
+    }
+
+    public AuthMethod[] getAuthMethod() {
+        return authMethod;
+    }
+
+    public void setAuthMethod(AuthMethod[] authMethod) {
+        this.authMethod = authMethod;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        Electronic that = (Electronic) o;
+        return Objects.equals(productNo, that.productNo) && Objects.equals(modelName, that.modelName) && companyName == that.companyName && Objects.equals(dateOfMade, that.dateOfMade) && Arrays.equals(authMethod, that.authMethod);
+    }
+
+    @Override
+    public int hashCode() {
+        int result = Objects.hash(productNo, modelName, companyName, dateOfMade);
+        result = 31 * result + Arrays.hashCode(authMethod);
+        return result;
+    }
+
+    @Override
+    public String toString() {
+        return "Electronic{" +
+                "productNo=" + productNo +
+                ", modelName='" + modelName + '\'' +
+                ", companyName=" + companyName +
+                ", dateOfMade=" + dateOfMade +
+                ", authMethod=" + Arrays.toString(authMethod) +
+                '}';
+    }
+}
+
diff --git a/src/main/java/practice1/User.java b/src/main/java/practice1/User.java
new file mode 100644
index 0000000..e9b547d
--- /dev/null
+++ b/src/main/java/practice1/User.java
@@ -0,0 +1,101 @@
+package practice1;
+
+import java.time.LocalDate;
+import java.time.LocalDateTime;
+import java.util.Arrays;
+import java.util.Objects;
+
+public class User {
+    private String userId;
+    private String userPassword;
+    private String userPhoneNumber;
+    private String userEmail;
+    private LocalDate userBirthDate;
+
+    private Electronic[] electronicDevices;
+    private LocalDateTime registerTime;
+
+    public String getUserId() {
+        return userId;
+    }
+
+    public void setUserId(String userId) {
+        this.userId = userId;
+    }
+
+    public String getUserPassword() {
+        return userPassword;
+    }
+
+    public void setUserPassword(String userPassword) {
+        this.userPassword = userPassword;
+    }
+
+    public String getUserPhoneNumber() {
+        return userPhoneNumber;
+    }
+
+    public void setUserPhoneNumber(String userPhoneNumber) {
+        this.userPhoneNumber = userPhoneNumber;
+    }
+
+    public String getUserEmail() {
+        return userEmail;
+    }
+
+    public void setUserEmail(String userEmail) {
+        this.userEmail = userEmail;
+    }
+
+    public LocalDate getUserBirthDate() {
+        return userBirthDate;
+    }
+
+    public void setUserBirthDate(LocalDate userBirthDate) {
+        this.userBirthDate = userBirthDate;
+    }
+
+    public Electronic[] getElectronicDevices() {
+        return electronicDevices;
+    }
+
+    public void setElectronicDevices(Electronic[] electronicDevices) {
+        this.electronicDevices = electronicDevices;
+    }
+
+    public LocalDateTime getRegisterTime() {
+        return registerTime;
+    }
+
+    public void setRegisterTime(LocalDateTime registerTime) {
+        this.registerTime = registerTime;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        User user = (User) o;
+        return Objects.equals(userId, user.userId) && Objects.equals(userPassword, user.userPassword) && Objects.equals(userPhoneNumber, user.userPhoneNumber) && Objects.equals(userEmail, user.userEmail) && Objects.equals(userBirthDate, user.userBirthDate) && Arrays.equals(electronicDevices, user.electronicDevices) && Objects.equals(registerTime, user.registerTime);
+    }
+
+    @Override
+    public int hashCode() {
+        int result = Objects.hash(userId, userPassword, userPhoneNumber, userEmail, userBirthDate, registerTime);
+        result = 31 * result + Arrays.hashCode(electronicDevices);
+        return result;
+    }
+
+    @Override
+    public String toString() {
+        return "User{" +
+                "userId='" + userId + '\'' +
+                ", userPassword='" + userPassword + '\'' +
+                ", userPhoneNumber='" + userPhoneNumber + '\'' +
+                ", userEmail='" + userEmail + '\'' +
+                ", userBirthDate=" + userBirthDate +
+                ", electronicDevices=" + Arrays.toString(electronicDevices) +
+                ", registerTime=" + registerTime +
+                '}';
+    }
+}

From 18269cf2660c877fb112edbe6fe5eaad10ebf9b2 Mon Sep 17 00:00:00 2001
From: brotherstone97 <brotherstone97@gmail.com>
Date: Mon, 17 Apr 2023 00:01:30 +0900
Subject: [PATCH 02/18] add: User constructor

---
 src/main/java/practice1/User.java | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/main/java/practice1/User.java b/src/main/java/practice1/User.java
index e9b547d..c283ff2 100644
--- a/src/main/java/practice1/User.java
+++ b/src/main/java/practice1/User.java
@@ -14,6 +14,14 @@ public class User {
 
     private Electronic[] electronicDevices;
     private LocalDateTime registerTime;
+    public User(String userId, String userPassword, String userPhoneNumber, String userEmail, LocalDate userBirthDate) {
+        this.userId = userId;
+        this.userPassword = userPassword;
+        this.userPhoneNumber = userPhoneNumber;
+        this.userEmail = userEmail;
+        this.userBirthDate = userBirthDate;
+        this.registerTime= LocalDateTime.now();
+    }
 
     public String getUserId() {
         return userId;

From 98a9ea0609333ecf405d7aae9553a5d4ef045d78 Mon Sep 17 00:00:00 2001
From: brotherstone97 <brotherstone97@gmail.com>
Date: Mon, 17 Apr 2023 00:33:43 +0900
Subject: [PATCH 03/18] feat(Electronic): create productNo

---
 src/main/java/practice1/Electronic.java | 27 +++++++++++++++++++++++--
 1 file changed, 25 insertions(+), 2 deletions(-)

diff --git a/src/main/java/practice1/Electronic.java b/src/main/java/practice1/Electronic.java
index 1356d07..85199e0 100644
--- a/src/main/java/practice1/Electronic.java
+++ b/src/main/java/practice1/Electronic.java
@@ -10,13 +10,36 @@ public class Electronic {
     private CompanyName companyName;
     private LocalDate dateOfMade;
     private AuthMethod[] authMethod;
+    private static int order = 0;
 
-    public Electronic(Long productNo, String modelName, CompanyName companyName, LocalDate dateOfMade, AuthMethod[] authMethod) {
-        this.productNo = productNo;
+    public Electronic(String modelName, CompanyName companyName, LocalDate dateOfMade, AuthMethod[] authMethod) {
         this.modelName = modelName;
         this.companyName = companyName;
         this.dateOfMade = dateOfMade;
         this.authMethod = authMethod;
+        createProductNo(this.dateOfMade);
+    }
+
+    private void createProductNo(LocalDate dateOfMade) {
+        int year = dateOfMade.getYear();
+        int month = dateOfMade.getMonthValue();
+        int day = dateOfMade.getDayOfMonth();
+
+        String no = year + month + day + makeOrderString();
+        productNo = Long.parseLong(no);
+    }
+
+    private String makeOrderString() {
+        if (order < 9) {
+            return "000" + (++order);
+        }
+        if (order < 99) {
+            return "00" + (++order);
+        }
+        if (order < 999) {
+            return "0" + (++order);
+        }
+        throw new IllegalArgumentException("등록순서는 네자리 수까지 가능합니다.");
     }
 
     public Long getProductNo() {

From f0e97a3b35f9ea93731f04698ce78b47fe112edf Mon Sep 17 00:00:00 2001
From: brotherstone97 <brotherstone97@gmail.com>
Date: Mon, 17 Apr 2023 01:56:29 +0900
Subject: [PATCH 04/18] test(Electronic): createProductNo()

---
 src/test/java/practice1/ElectronicTest.java | 28 +++++++++++++++++++++
 1 file changed, 28 insertions(+)
 create mode 100644 src/test/java/practice1/ElectronicTest.java

diff --git a/src/test/java/practice1/ElectronicTest.java b/src/test/java/practice1/ElectronicTest.java
new file mode 100644
index 0000000..dbb21fc
--- /dev/null
+++ b/src/test/java/practice1/ElectronicTest.java
@@ -0,0 +1,28 @@
+package practice1;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import java.time.LocalDate;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+
+class ElectronicTest {
+    Electronic electronic;
+
+    @BeforeEach
+    void setUp() {
+        electronic = new Electronic(
+                "SM-1000",
+                CompanyName.SAMSUNG,
+                LocalDate.of(2023, 04, 17),
+                new AuthMethod[]{AuthMethod.PIN, AuthMethod.PATTERN});
+    }
+
+    @Test
+    void createProductNo() {
+        Long productNo = electronic.getProductNo();
+        assertThat(productNo).isEqualTo(2304170001L);
+    }
+}
\ No newline at end of file

From f75414b8b0ac79af469a4271f3e4a325c2273de2 Mon Sep 17 00:00:00 2001
From: brotherstone97 <brotherstone97@gmail.com>
Date: Mon, 17 Apr 2023 02:02:30 +0900
Subject: [PATCH 05/18] fix(Electronic): error generating incorrect productNo

---
 src/main/java/practice1/Electronic.java | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/src/main/java/practice1/Electronic.java b/src/main/java/practice1/Electronic.java
index 85199e0..16d138e 100644
--- a/src/main/java/practice1/Electronic.java
+++ b/src/main/java/practice1/Electronic.java
@@ -22,13 +22,23 @@ public Electronic(String modelName, CompanyName companyName, LocalDate dateOfMad
 
     private void createProductNo(LocalDate dateOfMade) {
         int year = dateOfMade.getYear();
-        int month = dateOfMade.getMonthValue();
-        int day = dateOfMade.getDayOfMonth();
-
+        year -= 2000;
+        String month = String.valueOf(dateOfMade.getMonthValue());
+        month=addZero(month);
+        String day = String.valueOf(dateOfMade.getDayOfMonth());
+        day=addZero(day);
+        System.out.println("year: " + year + " month: " + month + " day: " + day);
         String no = year + month + day + makeOrderString();
         productNo = Long.parseLong(no);
     }
 
+    private String addZero(String date){
+        if(date.length()==1){
+            date = "0" + date;
+        }
+        return date;
+    }
+
     private String makeOrderString() {
         if (order < 9) {
             return "000" + (++order);

From abbe4e65004ecd4b8e0a4423191c4af0f6f67115 Mon Sep 17 00:00:00 2001
From: brotherstone97 <brotherstone97@gmail.com>
Date: Mon, 17 Apr 2023 15:03:52 +0900
Subject: [PATCH 06/18] solve practice2

---
 .gitignore                         |  1 +
 build.gradle                       |  1 +
 src/main/java/practice1/Users.java | 67 ++++++++++++++++++++++++++++++
 3 files changed, 69 insertions(+)
 create mode 100644 src/main/java/practice1/Users.java

diff --git a/.gitignore b/.gitignore
index 6db4f2e..3cbef4a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
 .gradle
 .idea
 gradle
+build
diff --git a/build.gradle b/build.gradle
index 3cae2d7..271edbd 100644
--- a/build.gradle
+++ b/build.gradle
@@ -12,6 +12,7 @@ repositories {
 dependencies {
     testImplementation 'org.junit.jupiter:junit-jupiter-api:5.8.1'
     testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine:5.8.1'
+    testImplementation group: 'org.assertj', name: 'assertj-core', version: '3.6.1'
 }
 
 test {
diff --git a/src/main/java/practice1/Users.java b/src/main/java/practice1/Users.java
new file mode 100644
index 0000000..1cddb84
--- /dev/null
+++ b/src/main/java/practice1/Users.java
@@ -0,0 +1,67 @@
+package practice1;
+
+import java.util.Arrays;
+
+public class Users {
+    private static Users users;
+    private User[] userList;
+
+    private static final int DEFAULT_CAPACITY = 50;
+
+    private Users() {
+        userList = new User[DEFAULT_CAPACITY];
+    }
+
+    public Users getInstance() {
+        if (users == null) {
+            users = new Users();
+        }
+        return users;
+    }
+
+    public User findByUserId(String userId) {
+        for (User user : userList) {
+            if (user.getUserId().equals(userId)) {
+                return user;
+            }
+        }
+        throw new IllegalArgumentException(userId + "를 가진 user를 찾을 수 없습니다.");
+    }
+
+    public User copy(User user) {
+        User copiedUser = new User(user.getUserId(), user.getUserPassword(), user.getUserPhoneNumber(),
+                user.getUserEmail(), user.getUserBirthDate());
+
+        copiedUser.setRegisterTime(user.getRegisterTime());
+
+        return copiedUser;
+    }
+
+    public static Users getUsers() {
+        return users;
+    }
+
+    public static void setUsers(Users users) {
+        Users.users = users;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        Users users = (Users) o;
+        return Arrays.equals(userList, users.userList);
+    }
+
+    @Override
+    public int hashCode() {
+        return Arrays.hashCode(userList);
+    }
+
+    @Override
+    public String toString() {
+        return "Users{" +
+                "userList=" + Arrays.toString(userList) +
+                '}';
+    }
+}

From 41f00c5dc90fdea31bc9beff9f801745a2cfdbb1 Mon Sep 17 00:00:00 2001
From: brotherstone97 <brotherstone97@gmail.com>
Date: Mon, 17 Apr 2023 15:39:17 +0900
Subject: [PATCH 07/18] rename Enum CompanyName to Company

---
 .../java/practice1/{CompanyName.java => Company.java}  |  2 +-
 src/main/java/practice1/Electronic.java                | 10 +++++-----
 src/test/java/practice1/ElectronicTest.java            |  2 +-
 3 files changed, 7 insertions(+), 7 deletions(-)
 rename src/main/java/practice1/{CompanyName.java => Company.java} (67%)

diff --git a/src/main/java/practice1/CompanyName.java b/src/main/java/practice1/Company.java
similarity index 67%
rename from src/main/java/practice1/CompanyName.java
rename to src/main/java/practice1/Company.java
index 148f91e..286d0d5 100644
--- a/src/main/java/practice1/CompanyName.java
+++ b/src/main/java/practice1/Company.java
@@ -1,6 +1,6 @@
 package practice1;
 
-public enum CompanyName {
+public enum Company {
     SAMSUNG,
     LG,
     APPLE,
diff --git a/src/main/java/practice1/Electronic.java b/src/main/java/practice1/Electronic.java
index 16d138e..96ec705 100644
--- a/src/main/java/practice1/Electronic.java
+++ b/src/main/java/practice1/Electronic.java
@@ -7,12 +7,12 @@
 public class Electronic {
     private Long productNo;
     private String modelName;
-    private CompanyName companyName;
+    private Company companyName;
     private LocalDate dateOfMade;
     private AuthMethod[] authMethod;
     private static int order = 0;
 
-    public Electronic(String modelName, CompanyName companyName, LocalDate dateOfMade, AuthMethod[] authMethod) {
+    public Electronic(String modelName, Company companyName, LocalDate dateOfMade, AuthMethod[] authMethod) {
         this.modelName = modelName;
         this.companyName = companyName;
         this.dateOfMade = dateOfMade;
@@ -68,12 +68,12 @@ public void setModelName(String modelName) {
         this.modelName = modelName;
     }
 
-    public CompanyName getCompanyName() {
+    public Company getCompanyName() {
         return companyName;
     }
 
-    public void setCompanyName(CompanyName companyName) {
-        this.companyName = companyName;
+    public void setCompanyName(Company company) {
+        this.companyName = company;
     }
 
     public LocalDate getDateOfMade() {
diff --git a/src/test/java/practice1/ElectronicTest.java b/src/test/java/practice1/ElectronicTest.java
index dbb21fc..f06fd98 100644
--- a/src/test/java/practice1/ElectronicTest.java
+++ b/src/test/java/practice1/ElectronicTest.java
@@ -15,7 +15,7 @@ class ElectronicTest {
     void setUp() {
         electronic = new Electronic(
                 "SM-1000",
-                CompanyName.SAMSUNG,
+                Company.SAMSUNG,
                 LocalDate.of(2023, 04, 17),
                 new AuthMethod[]{AuthMethod.PIN, AuthMethod.PATTERN});
     }

From 925e95927459ab9b5a69788290d4f7e58c72cd78 Mon Sep 17 00:00:00 2001
From: brotherstone97 <brotherstone97@gmail.com>
Date: Mon, 17 Apr 2023 15:39:33 +0900
Subject: [PATCH 08/18] solve practice3

---
 src/main/java/practice1/Electronics.java | 106 +++++++++++++++++++++++
 1 file changed, 106 insertions(+)
 create mode 100644 src/main/java/practice1/Electronics.java

diff --git a/src/main/java/practice1/Electronics.java b/src/main/java/practice1/Electronics.java
new file mode 100644
index 0000000..543ae38
--- /dev/null
+++ b/src/main/java/practice1/Electronics.java
@@ -0,0 +1,106 @@
+package practice1;
+
+import java.util.Arrays;
+
+public class Electronics {
+    private static Electronics electronics;
+
+    private Electronic[] electronicList;
+
+    private static final int DEFAULT_CAPACITY = 50;
+
+
+    private Electronics() {
+        electronicList = new Electronic[DEFAULT_CAPACITY];
+    }
+
+    public static Electronics getInstance() {
+        if (electronics == null) {
+            electronics = new Electronics();
+        }
+        return electronics;
+    }
+
+    public Electronic findByProductNo(Long productNo) {
+        for (Electronic electronic : electronicList) {
+            if (electronic.getProductNo().equals(productNo)) {
+                return electronic;
+            }
+        }
+        throw new IllegalArgumentException("상품번호 " + productNo + "에 해당하는 전자제품을 찾을 수 없습니다.");
+    }
+
+    public Electronic[] groupByCompanyName(Company company) {
+        Electronic[] companyProducts = new Electronic[DEFAULT_CAPACITY];
+        int idx = 0;
+        for (Electronic electronic : electronicList) {
+            if (electronic.getCompanyName().equals(company)) {
+                companyProducts[idx++] = electronic;
+            }
+        }
+        if (idx == 0) {
+            throw new IllegalArgumentException("제조사 " + company + "의 전자제품을 찾을 수 없습니다.");
+        }
+        cutArray(companyProducts);
+        return companyProducts;
+    }
+
+    public Electronic[] groupByAuthMethod(AuthMethod authMethod) {
+        Electronic[] authMethodProducts = new Electronic[DEFAULT_CAPACITY];
+        int idx = 0;
+        for (Electronic electronic : electronicList) {
+            for (AuthMethod method : electronic.getAuthMethod()) {
+                if (method.equals(authMethod)) {
+                    authMethodProducts[idx] = electronic;
+                    idx++;
+                    break;
+                }
+            }
+        }
+        if (idx == 0) {
+            throw new IllegalArgumentException(authMethod + " 인증방법을 탑재한 전자제품을 찾을 수 없습니다.");
+        }
+        cutArray(authMethodProducts);
+        return authMethodProducts;
+    }
+
+    private void cutArray(Electronic[] newElectronicList) {
+        int idx = 0;
+        for (Electronic e : newElectronicList) {
+            if (e == null) {
+                break;
+            }
+            idx++;
+        }
+        newElectronicList = Arrays.copyOf(newElectronicList, idx);
+    }
+
+
+    public Electronic[] getElectronicList() {
+        return electronicList;
+    }
+
+    public void setElectronicList(Electronic[] electronicList) {
+        this.electronicList = electronicList;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        Electronics that = (Electronics) o;
+        return Arrays.equals(electronicList, that.electronicList);
+    }
+
+    @Override
+    public int hashCode() {
+        return Arrays.hashCode(electronicList);
+    }
+
+    @Override
+    public String toString() {
+        return "Electronics{" +
+                "electronicList=" + Arrays.toString(electronicList) +
+                '}';
+    }
+}

From 18557e2d6c2e682763bc12c9cc82bfa4f9b02025 Mon Sep 17 00:00:00 2001
From: brotherstone97 <brotherstone97@gmail.com>
Date: Fri, 28 Apr 2023 22:07:13 +0900
Subject: [PATCH 09/18] style: apply consistent code style

Removed unnecessary enum commas and changed statement orders, variable names
---
 src/main/java/practice1/AuthMethod.java  |  2 +-
 src/main/java/practice1/Company.java     |  2 +-
 src/main/java/practice1/Electronic.java  | 29 ++++++++++++------------
 src/main/java/practice1/Electronics.java |  3 +--
 src/main/java/practice1/User.java        |  2 +-
 src/main/java/practice1/Users.java       |  4 ++--
 6 files changed, 21 insertions(+), 21 deletions(-)

diff --git a/src/main/java/practice1/AuthMethod.java b/src/main/java/practice1/AuthMethod.java
index 99cec3d..154609a 100644
--- a/src/main/java/practice1/AuthMethod.java
+++ b/src/main/java/practice1/AuthMethod.java
@@ -4,5 +4,5 @@ public enum AuthMethod {
     PIN,
     PATTERN,
     FACE_ID,
-    FINGERPRINT,
+    FINGERPRINT
 }
diff --git a/src/main/java/practice1/Company.java b/src/main/java/practice1/Company.java
index 286d0d5..5cbb5b6 100644
--- a/src/main/java/practice1/Company.java
+++ b/src/main/java/practice1/Company.java
@@ -3,5 +3,5 @@
 public enum Company {
     SAMSUNG,
     LG,
-    APPLE,
+    APPLE
 }
diff --git a/src/main/java/practice1/Electronic.java b/src/main/java/practice1/Electronic.java
index 96ec705..f1dd10e 100644
--- a/src/main/java/practice1/Electronic.java
+++ b/src/main/java/practice1/Electronic.java
@@ -5,18 +5,19 @@
 import java.util.Objects;
 
 public class Electronic {
+    private static int order = 0;
+
     private Long productNo;
     private String modelName;
     private Company companyName;
     private LocalDate dateOfMade;
-    private AuthMethod[] authMethod;
-    private static int order = 0;
+    private AuthMethod[] authMethods;
 
-    public Electronic(String modelName, Company companyName, LocalDate dateOfMade, AuthMethod[] authMethod) {
+    public Electronic(String modelName, Company companyName, LocalDate dateOfMade, AuthMethod[] authMethods) {
         this.modelName = modelName;
         this.companyName = companyName;
         this.dateOfMade = dateOfMade;
-        this.authMethod = authMethod;
+        this.authMethods = authMethods;
         createProductNo(this.dateOfMade);
     }
 
@@ -24,16 +25,16 @@ private void createProductNo(LocalDate dateOfMade) {
         int year = dateOfMade.getYear();
         year -= 2000;
         String month = String.valueOf(dateOfMade.getMonthValue());
-        month=addZero(month);
+        month = addZero(month);
         String day = String.valueOf(dateOfMade.getDayOfMonth());
-        day=addZero(day);
+        day = addZero(day);
         System.out.println("year: " + year + " month: " + month + " day: " + day);
         String no = year + month + day + makeOrderString();
         productNo = Long.parseLong(no);
     }
 
-    private String addZero(String date){
-        if(date.length()==1){
+    private String addZero(String date) {
+        if (date.length() == 1) {
             date = "0" + date;
         }
         return date;
@@ -85,11 +86,11 @@ public void setDateOfMade(LocalDate dateOfMade) {
     }
 
     public AuthMethod[] getAuthMethod() {
-        return authMethod;
+        return authMethods;
     }
 
-    public void setAuthMethod(AuthMethod[] authMethod) {
-        this.authMethod = authMethod;
+    public void setAuthMethod(AuthMethod[] authMethods) {
+        this.authMethods = authMethods;
     }
 
     @Override
@@ -97,13 +98,13 @@ public boolean equals(Object o) {
         if (this == o) return true;
         if (o == null || getClass() != o.getClass()) return false;
         Electronic that = (Electronic) o;
-        return Objects.equals(productNo, that.productNo) && Objects.equals(modelName, that.modelName) && companyName == that.companyName && Objects.equals(dateOfMade, that.dateOfMade) && Arrays.equals(authMethod, that.authMethod);
+        return Objects.equals(productNo, that.productNo) && Objects.equals(modelName, that.modelName) && companyName == that.companyName && Objects.equals(dateOfMade, that.dateOfMade) && Arrays.equals(authMethods, that.authMethods);
     }
 
     @Override
     public int hashCode() {
         int result = Objects.hash(productNo, modelName, companyName, dateOfMade);
-        result = 31 * result + Arrays.hashCode(authMethod);
+        result = 31 * result + Arrays.hashCode(authMethods);
         return result;
     }
 
@@ -114,7 +115,7 @@ public String toString() {
                 ", modelName='" + modelName + '\'' +
                 ", companyName=" + companyName +
                 ", dateOfMade=" + dateOfMade +
-                ", authMethod=" + Arrays.toString(authMethod) +
+                ", authMethods=" + Arrays.toString(authMethods) +
                 '}';
     }
 }
diff --git a/src/main/java/practice1/Electronics.java b/src/main/java/practice1/Electronics.java
index 543ae38..c3d2f36 100644
--- a/src/main/java/practice1/Electronics.java
+++ b/src/main/java/practice1/Electronics.java
@@ -3,12 +3,11 @@
 import java.util.Arrays;
 
 public class Electronics {
+    private static final int DEFAULT_CAPACITY = 50;
     private static Electronics electronics;
 
     private Electronic[] electronicList;
 
-    private static final int DEFAULT_CAPACITY = 50;
-
 
     private Electronics() {
         electronicList = new Electronic[DEFAULT_CAPACITY];
diff --git a/src/main/java/practice1/User.java b/src/main/java/practice1/User.java
index c283ff2..c381f66 100644
--- a/src/main/java/practice1/User.java
+++ b/src/main/java/practice1/User.java
@@ -11,9 +11,9 @@ public class User {
     private String userPhoneNumber;
     private String userEmail;
     private LocalDate userBirthDate;
-
     private Electronic[] electronicDevices;
     private LocalDateTime registerTime;
+
     public User(String userId, String userPassword, String userPhoneNumber, String userEmail, LocalDate userBirthDate) {
         this.userId = userId;
         this.userPassword = userPassword;
diff --git a/src/main/java/practice1/Users.java b/src/main/java/practice1/Users.java
index 1cddb84..a2fcf4a 100644
--- a/src/main/java/practice1/Users.java
+++ b/src/main/java/practice1/Users.java
@@ -3,11 +3,11 @@
 import java.util.Arrays;
 
 public class Users {
+    private static final int DEFAULT_CAPACITY = 50;
+
     private static Users users;
     private User[] userList;
 
-    private static final int DEFAULT_CAPACITY = 50;
-
     private Users() {
         userList = new User[DEFAULT_CAPACITY];
     }

From 7cee59c7a09841a7d941eff64b7c94217473427c Mon Sep 17 00:00:00 2001
From: brotherstone97 <brotherstone97@gmail.com>
Date: Fri, 28 Apr 2023 23:42:09 +0900
Subject: [PATCH 10/18] refactor: set productNo in constructor

---
 src/main/java/practice1/Electronic.java | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/main/java/practice1/Electronic.java b/src/main/java/practice1/Electronic.java
index f1dd10e..ef0cdf1 100644
--- a/src/main/java/practice1/Electronic.java
+++ b/src/main/java/practice1/Electronic.java
@@ -18,10 +18,10 @@ public Electronic(String modelName, Company companyName, LocalDate dateOfMade, A
         this.companyName = companyName;
         this.dateOfMade = dateOfMade;
         this.authMethods = authMethods;
-        createProductNo(this.dateOfMade);
+        this.productNo = createProductNo(this.dateOfMade);
     }
 
-    private void createProductNo(LocalDate dateOfMade) {
+    private Long createProductNo(LocalDate dateOfMade) {
         int year = dateOfMade.getYear();
         year -= 2000;
         String month = String.valueOf(dateOfMade.getMonthValue());
@@ -31,6 +31,7 @@ private void createProductNo(LocalDate dateOfMade) {
         System.out.println("year: " + year + " month: " + month + " day: " + day);
         String no = year + month + day + makeOrderString();
         productNo = Long.parseLong(no);
+        return productNo;
     }
 
     private String addZero(String date) {

From 0841b5eeda081c0d922972320d4a9a36592bfdb4 Mon Sep 17 00:00:00 2001
From: brotherstone97 <brotherstone97@gmail.com>
Date: Fri, 28 Apr 2023 23:43:30 +0900
Subject: [PATCH 11/18] refactor: remove debug code

---
 src/main/java/practice1/Electronic.java | 1 -
 1 file changed, 1 deletion(-)

diff --git a/src/main/java/practice1/Electronic.java b/src/main/java/practice1/Electronic.java
index ef0cdf1..39ca0a8 100644
--- a/src/main/java/practice1/Electronic.java
+++ b/src/main/java/practice1/Electronic.java
@@ -28,7 +28,6 @@ private Long createProductNo(LocalDate dateOfMade) {
         month = addZero(month);
         String day = String.valueOf(dateOfMade.getDayOfMonth());
         day = addZero(day);
-        System.out.println("year: " + year + " month: " + month + " day: " + day);
         String no = year + month + day + makeOrderString();
         productNo = Long.parseLong(no);
         return productNo;

From 483bb259530b9ceb3be09bfe581d72f731b15258 Mon Sep 17 00:00:00 2001
From: brotherstone97 <brotherstone97@gmail.com>
Date: Sat, 29 Apr 2023 00:30:27 +0900
Subject: [PATCH 12/18] refactor: use StringBuilder instead of operating String
 concat

---
 src/main/java/practice1/Electronic.java | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/src/main/java/practice1/Electronic.java b/src/main/java/practice1/Electronic.java
index 39ca0a8..5b1ae79 100644
--- a/src/main/java/practice1/Electronic.java
+++ b/src/main/java/practice1/Electronic.java
@@ -28,11 +28,27 @@ private Long createProductNo(LocalDate dateOfMade) {
         month = addZero(month);
         String day = String.valueOf(dateOfMade.getDayOfMonth());
         day = addZero(day);
-        String no = year + month + day + makeOrderString();
-        productNo = Long.parseLong(no);
+
+        String orderString = makeOrderString();
+        String[] date = new String[]{
+                String.valueOf(year),
+                month,
+                day,
+                orderString
+        };
+        StringBuilder noStringBuilder = stringArrToStringBuilder(date);
+        productNo = Long.parseLong(noStringBuilder.toString());
         return productNo;
     }
 
+    private StringBuilder stringArrToStringBuilder(String[] arr) {
+        StringBuilder sb = new StringBuilder();
+        for (String e : arr) {
+            sb.append(e);
+        }
+        return sb;
+    }
+
     private String addZero(String date) {
         if (date.length() == 1) {
             date = "0" + date;

From a4df258479587aab39efbc2b478a69f00427d4c6 Mon Sep 17 00:00:00 2001
From: brotherstone97 <brotherstone97@gmail.com>
Date: Sat, 29 Apr 2023 18:50:29 +0900
Subject: [PATCH 13/18] fix: getInstance() method to static method

---
 src/main/java/practice1/Users.java | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/main/java/practice1/Users.java b/src/main/java/practice1/Users.java
index a2fcf4a..24108cb 100644
--- a/src/main/java/practice1/Users.java
+++ b/src/main/java/practice1/Users.java
@@ -12,7 +12,7 @@ private Users() {
         userList = new User[DEFAULT_CAPACITY];
     }
 
-    public Users getInstance() {
+    public static Users getInstance() {
         if (users == null) {
             users = new Users();
         }

From 34bba61f0762a7ab903a0a0686c0fb58eb76551b Mon Sep 17 00:00:00 2001
From: brotherstone97 <brotherstone97@gmail.com>
Date: Sat, 29 Apr 2023 20:23:12 +0900
Subject: [PATCH 14/18] refactor(findByProductNo): use stream

---
 src/main/java/practice1/Electronics.java | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/src/main/java/practice1/Electronics.java b/src/main/java/practice1/Electronics.java
index c3d2f36..c3f7f65 100644
--- a/src/main/java/practice1/Electronics.java
+++ b/src/main/java/practice1/Electronics.java
@@ -1,6 +1,10 @@
 package practice1;
 
 import java.util.Arrays;
+import java.util.List;
+import java.util.Optional;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
 
 public class Electronics {
     private static final int DEFAULT_CAPACITY = 50;
@@ -21,10 +25,12 @@ public static Electronics getInstance() {
     }
 
     public Electronic findByProductNo(Long productNo) {
-        for (Electronic electronic : electronicList) {
-            if (electronic.getProductNo().equals(productNo)) {
-                return electronic;
-            }
+        Stream<Electronic> productStream = Arrays.stream(electronicList);
+        Optional<Electronic> filtered = productStream
+                .filter(product -> product.getProductNo().equals(productNo))
+                .findFirst();
+        if (filtered.isPresent()) {
+            return filtered.get();
         }
         throw new IllegalArgumentException("상품번호 " + productNo + "에 해당하는 전자제품을 찾을 수 없습니다.");
     }

From d88bc5d9b31bbb8726681eaade594b0060112855 Mon Sep 17 00:00:00 2001
From: brotherstone97 <brotherstone97@gmail.com>
Date: Sat, 29 Apr 2023 20:28:20 +0900
Subject: [PATCH 15/18] test: add test for findByProductNo()

---
 src/test/java/practice1/ElectronicTest.java | 24 +++++++++++++++++----
 1 file changed, 20 insertions(+), 4 deletions(-)

diff --git a/src/test/java/practice1/ElectronicTest.java b/src/test/java/practice1/ElectronicTest.java
index f06fd98..e23613f 100644
--- a/src/test/java/practice1/ElectronicTest.java
+++ b/src/test/java/practice1/ElectronicTest.java
@@ -1,23 +1,27 @@
 package practice1;
 
-import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.Test;
 
 import java.time.LocalDate;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
 
 
 class ElectronicTest {
-    Electronic electronic;
+    static Electronic electronic;
+    static Electronics electronics;
 
-    @BeforeEach
-    void setUp() {
+    @BeforeAll
+    static void setUp() {
         electronic = new Electronic(
                 "SM-1000",
                 Company.SAMSUNG,
                 LocalDate.of(2023, 04, 17),
                 new AuthMethod[]{AuthMethod.PIN, AuthMethod.PATTERN});
+        electronics = Electronics.getInstance();
+        electronics.setElectronicList(new Electronic[]{electronic});
     }
 
     @Test
@@ -25,4 +29,16 @@ void createProductNo() {
         Long productNo = electronic.getProductNo();
         assertThat(productNo).isEqualTo(2304170001L);
     }
+
+    @Test
+    void findExistentProductNo() {
+        Electronic found = electronics.findByProductNo(2304170001L);
+        assertThat(found.getProductNo()).isEqualTo(2304170001L);
+    }
+
+    @Test
+    void findNonexistentProductNo() {
+        assertThatThrownBy(() -> {electronics.findByProductNo(2311132L);})
+                .isInstanceOf(IllegalArgumentException.class);
+    }
 }
\ No newline at end of file

From 035b1ef8cdddfbd3afd38b0737b80e6e5ef4d489 Mon Sep 17 00:00:00 2001
From: brotherstone97 <brotherstone97@gmail.com>
Date: Sun, 30 Apr 2023 01:02:04 +0900
Subject: [PATCH 16/18] refactor(findByUserId): use stream

---
 src/main/java/practice1/Users.java | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/src/main/java/practice1/Users.java b/src/main/java/practice1/Users.java
index 24108cb..62d9a2f 100644
--- a/src/main/java/practice1/Users.java
+++ b/src/main/java/practice1/Users.java
@@ -1,6 +1,8 @@
 package practice1;
 
 import java.util.Arrays;
+import java.util.Optional;
+import java.util.stream.Stream;
 
 public class Users {
     private static final int DEFAULT_CAPACITY = 50;
@@ -20,10 +22,12 @@ public static Users getInstance() {
     }
 
     public User findByUserId(String userId) {
-        for (User user : userList) {
-            if (user.getUserId().equals(userId)) {
-                return user;
-            }
+        Stream<User> userStream = Arrays.stream(userList);
+        Optional<User> filtered = userStream
+                .filter(user -> user.getUserId().equals(userId))
+                .findFirst();
+        if(filtered.isPresent()){
+            return filtered.get();
         }
         throw new IllegalArgumentException(userId + "를 가진 user를 찾을 수 없습니다.");
     }
@@ -37,6 +41,10 @@ public User copy(User user) {
         return copiedUser;
     }
 
+    public void setUserList(User[] userList) {
+        this.userList = userList;
+    }
+
     public static Users getUsers() {
         return users;
     }

From e45e4d64d909930661c0f03d36023bbe61513a3b Mon Sep 17 00:00:00 2001
From: brotherstone97 <brotherstone97@gmail.com>
Date: Sun, 30 Apr 2023 01:02:35 +0900
Subject: [PATCH 17/18] test: add test for findByUserId()

---
 src/test/java/practice1/UsersTest.java | 36 ++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)
 create mode 100644 src/test/java/practice1/UsersTest.java

diff --git a/src/test/java/practice1/UsersTest.java b/src/test/java/practice1/UsersTest.java
new file mode 100644
index 0000000..cbb774b
--- /dev/null
+++ b/src/test/java/practice1/UsersTest.java
@@ -0,0 +1,36 @@
+package practice1;
+
+import org.assertj.core.api.Assertions;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+
+import java.time.LocalDate;
+
+import static org.assertj.core.api.Assertions.*;
+import static org.junit.jupiter.api.Assertions.*;
+
+class UsersTest {
+    static Users users;
+    static User user;
+
+    @BeforeAll
+    static void setUp() {
+        user = new User("test1", "password1", "010-6255-7191"
+                , "brotherstone97@gmail.com", LocalDate.of(1997, 11, 14));
+        users = Users.getInstance();
+        users.setUserList(new User[]{user});
+    }
+
+    @Test
+    void findByUserId() {
+        User newUser = users.findByUserId("test1");
+        assertThat(newUser.getUserId()).isEqualTo("test1");
+    }
+
+    @Test
+    void findNonExistentUserId() {
+        assertThatThrownBy(()->{
+            User newUser = users.findByUserId("test2");
+        }).isInstanceOf(IllegalArgumentException.class);
+    }
+}
\ No newline at end of file

From 9eade7e434aaa99d197c62fad311364b59b32024 Mon Sep 17 00:00:00 2001
From: brotherstone97 <brotherstone97@gmail.com>
Date: Sun, 30 Apr 2023 01:25:10 +0900
Subject: [PATCH 18/18] rename method cutArray to removeEmptyElements

---
 src/main/java/practice1/Electronics.java | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/src/main/java/practice1/Electronics.java b/src/main/java/practice1/Electronics.java
index c3f7f65..cf2de4d 100644
--- a/src/main/java/practice1/Electronics.java
+++ b/src/main/java/practice1/Electronics.java
@@ -46,7 +46,7 @@ public Electronic[] groupByCompanyName(Company company) {
         if (idx == 0) {
             throw new IllegalArgumentException("제조사 " + company + "의 전자제품을 찾을 수 없습니다.");
         }
-        cutArray(companyProducts);
+        removeEmptyElements(companyProducts);
         return companyProducts;
     }
 
@@ -65,11 +65,12 @@ public Electronic[] groupByAuthMethod(AuthMethod authMethod) {
         if (idx == 0) {
             throw new IllegalArgumentException(authMethod + " 인증방법을 탑재한 전자제품을 찾을 수 없습니다.");
         }
-        cutArray(authMethodProducts);
+        removeEmptyElements(authMethodProducts);
         return authMethodProducts;
     }
 
-    private void cutArray(Electronic[] newElectronicList) {
+    private void removeEmptyElements(Electronic[] newElectronicList) {
+
         int idx = 0;
         for (Electronic e : newElectronicList) {
             if (e == null) {