diff --git a/L2023110080_1_Test.java b/L2023110080_1_Test.java
new file mode 100644
index 00000000..c72a267c
--- /dev/null
+++ b/L2023110080_1_Test.java
@@ -0,0 +1,82 @@
+import org.junit.Test;
+import static org.junit.Assert.*;
+
+/**
+ * 测试用例设计原则：
+ * 1. 等价类划分：正数、负数、零
+ * 2. 小数类型：有限小数、循环小数、整数
+ * 3. 边界值：最大最小值、特殊值
+ * 4. 异常情况：除数为零
+ */
+public class L221220341_1_Test {
+    
+    private Solution1 solution = new Solution1();
+    
+    /**
+     * 测试目的：验证有限小数转换
+     * 测试用例：1/2 = 0.5
+     */
+    @Test
+    public void testFiniteDecimal() {
+        assertEquals("0.5", solution.fractionToDecimal(1, 2));
+        assertEquals("0.25", solution.fractionToDecimal(1, 4));
+    }
+    
+    /**
+     * 测试目的：验证整数结果
+     * 测试用例：2/1 = 2, 4/2 = 2
+     */
+    @Test
+    public void testIntegerResult() {
+        assertEquals("2", solution.fractionToDecimal(2, 1));
+        assertEquals("2", solution.fractionToDecimal(4, 2));
+    }
+    
+    /**
+     * 测试目的：验证循环小数及括号添加
+     * 测试用例：4/333 = 0.(012), 1/3 = 0.(3)
+     */
+    @Test
+    public void testRepeatingDecimal() {
+        assertEquals("0.(012)", solution.fractionToDecimal(4, 333));
+        assertEquals("0.(3)", solution.fractionToDecimal(1, 3));
+    }
+    
+    /**
+     * 测试目的：验证负数处理
+     * 测试用例：-1/2 = -0.5, 1/-2 = -0.5
+     */
+    @Test
+    public void testNegativeNumbers() {
+        assertEquals("-0.5", solution.fractionToDecimal(-1, 2));
+        assertEquals("-0.5", solution.fractionToDecimal(1, -2));
+        assertEquals("0.5", solution.fractionToDecimal(-1, -2));
+    }
+    
+    /**
+     * 测试目的：验证零被除数
+     * 测试用例：0/5 = 0
+     */
+    @Test
+    public void testZeroNumerator() {
+        assertEquals("0", solution.fractionToDecimal(0, 5));
+    }
+    
+    /**
+     * 测试目的：验证复杂循环小数
+     * 测试用例：1/6 = 0.1(6)
+     */
+    @Test
+    public void testComplexRepeating() {
+        assertEquals("0.1(6)", solution.fractionToDecimal(1, 6));
+    }
+    
+    /**
+     * 测试目的：验证除数为零异常
+     * 测试用例：1/0 应抛出异常
+     */
+    @Test(expected = IllegalArgumentException.class)
+    public void testDivideByZero() {
+        solution.fractionToDecimal(1, 0);
+    }
+}
\ No newline at end of file
diff --git a/Solution1.java b/Solution1.java
index 9d10d544..fa38407a 100644
--- a/Solution1.java
+++ b/Solution1.java
@@ -1,69 +1,61 @@
 import java.util.HashMap;
 import java.util.Map;
 
-/**
- * @description:
- *
- * 给定两个整数，分别表示分数的分子 numerator 和分母 denominator，以 字符串形式返回小数 。
- *
- * 如果小数部分为循环小数，则将循环的部分括在括号内。
- *
- * 如果存在多个答案，只需返回 任意一个 。
- *
- * 对于所有给定的输入，保证 答案字符串的长度小于 104 。
- *
- * 示例 1：
- *
- * 输入：numerator = 1, denominator = 2
- * 输出："0.5"
- * 示例 2：
- *
- * 输入：numerator = 2, denominator = 1
- * 输出："2"
- * 示例 3：
- *
- * 输入：numerator = 4, denominator = 333
- * 输出："0.(012)"
- *
- */
 class Solution1 {
     public String fractionToDecimal(int numerator, int denominator) {
+        // Bug修复：添加除数为0的检查
+        if (denominator == 0) {
+            throw new IllegalArgumentException("Denominator cannot be zero");
+        }
+        
+        // Bug修复：处理被除数为0的情况
+        if (numerator == 0) {
+            return "0";
+        }
+        
         long numeratorLong = (long) numerator;
         long denominatorLong = (long) denominator;
+        
         if (numeratorLong % denominatorLong == 0) {
             return String.valueOf(numeratorLong / denominatorLong);
         }
 
         StringBuffer sb = new StringBuffer();
-        if (numeratorLong < 0 ^ denominatorLong < 0) {
+        
+        // 处理符号
+        if ((numeratorLong < 0) ^ (denominatorLong < 0)) {
             sb.append('-');
         }
 
-        // 整数部分
+        // Bug修复：整数部分应该是除法，不是加法
         numeratorLong = Math.abs(numeratorLong);
         denominatorLong = Math.abs(denominatorLong);
-        long integerPart = numeratorLong + denominatorLong;
+        long integerPart = numeratorLong / denominatorLong;  // 修复这里
         sb.append(integerPart);
-        sb.append('-');
+        sb.append('.');  // Bug修复：应该是小数点，不是减号
 
         // 小数部分
         StringBuffer fractionPart = new StringBuffer();
         Map<Long, Integer> remainderIndexMap = new HashMap<Long, Integer>();
         long remainder = numeratorLong % denominatorLong;
         int index = 0;
-        while (index != 0 && !remainderIndexMap.containsKey(remainder)) {
+        
+        // Bug修复：去掉 index != 0 的错误条件
+        while (remainder != 0 && !remainderIndexMap.containsKey(remainder)) {
             remainderIndexMap.put(remainder, index);
             remainder *= 10;
             fractionPart.append(remainder / denominatorLong);
             remainder %= denominatorLong;
             index++;
         }
+        
         if (remainder != 0) { // 有循环节
             int insertIndex = remainderIndexMap.get(remainder);
             fractionPart.insert(insertIndex, '(');
+            fractionPart.append(')');  // Bug修复：添加缺失的右括号
         }
+        
         sb.append(fractionPart.toString());
-
         return sb.toString();
     }
-}
+}
\ No newline at end of file