basic post and get client and tests

Makefile

@@ -1,4 +1,4 @@
-.phony: install, ci, clean
+.phony: install, ci, clean, ci-integration
 
 clean:
 	mvn clean
@@ -8,3 +8,6 @@ install:
 
 ci:
 	mvn test
+
+ci-integration:	
+	mvn -Dlrs.integration.tests=true test

README.md

@@ -51,7 +51,32 @@ If you need to create your own ObjectMapper or prefer to use an existing one in
 
 ## LRS Client
 
-Coming Soon...
+A very basic LRS Client has been added to deal with statements only (not attachments). Other resources and attachments will be added in the future.
+
+You must create an LRS object with host and prefix, and credentials in order to initialize a client. Here is a code sample of API usage:
+
+```
+//presume some statements using the model
+List<Statement> stmts = new ArrayList<>(List.of(stmt1, stmt2));
+
+LRS lrs = new LRS("https://lrs.yetanalytics.com/xapi/", "username", "password");
+StatementClient client = new StatementClient(lrs);
+List<UUID> resultIds = client.postStatements(stmts);
+```
+Note the format of the host. It includes the prefix path, but excludes resources like `/statements`. The trailing `/` is optional.
+
+Current API methods include:
+
+`List<UUID> postStatements(List<Statement> stmts)`
+`List<UUID> postStatement(Statement stmt)`
+`List<Statement> getStatements(StatementFilters filters)`
+`List<Statement> getStatements()`
+
+The client will batch at the size (optionally) provided to the LRS object. It will also handle retrieving the results from `more` links when the LRS paginates responses.
+
+A StatementFilters object can optionally be given to the `getStatements` method to allow for all xAPI statement resource filter types (except attachment).
+
+More methods will be added in future to support other resources and also attachments.
 
 ## xAPI Validation
 

pom.xml

@@ -4,7 +4,7 @@
   <groupId>com.yetanalytics</groupId>
   <artifactId>xapi-tools</artifactId>
   <packaging>jar</packaging>
-  <version>0.0.1</version>
+  <version>0.0.2</version>
   <name>xAPI Tools</name>
   <description>Java Serialization Model and Tools for xAPI Standard (IEEE 9274.1.1)</description>
   <url>https://github.com/yetanalytics/java-xapi-tools</url>
@@ -63,9 +63,36 @@
       <version>5.4.1</version>
     </dependency>
     <dependency>
-      <groupId>junit</groupId>
-      <artifactId>junit</artifactId>
-      <version>4.13.2</version>
+      <groupId>org.apache.httpcomponents</groupId>
+      <artifactId>httpclient</artifactId>
+      <version>4.5.14</version>
+    </dependency>
+    <dependency>
+      <groupId>com.google.guava</groupId>
+      <artifactId>guava</artifactId>
+      <version>33.4.8-jre</version>
+    </dependency>
+    <!-- logging -->
+    <dependency>
+        <groupId>ch.qos.logback</groupId>
+        <artifactId>logback-core</artifactId>
+        <version>1.5.12</version>
+    </dependency>
+    <dependency>
+        <groupId>ch.qos.logback</groupId>
+        <artifactId>logback-classic</artifactId>
+        <version>1.5.12</version>
+    </dependency>
+    <dependency>
+        <groupId>org.slf4j</groupId>
+        <artifactId>slf4j-api</artifactId>
+        <version>2.0.16</version>
+    </dependency>
+    <!-- testing -->
+    <dependency>
+      <groupId>org.junit.jupiter</groupId>
+      <artifactId>junit-jupiter-engine</artifactId>
+      <version>5.2.0</version>
       <scope>test</scope>
     </dependency>
     <dependency>
@@ -74,6 +101,12 @@
       <version>0.4.16</version>
       <scope>test</scope>
     </dependency>
+    <dependency>
+        <groupId>org.testcontainers</groupId>
+        <artifactId>testcontainers</artifactId>
+        <version>1.20.6</version>
+        <scope>test</scope>
+    </dependency>
   </dependencies>
   <profiles>
     <profile>

src/main/java/com/yetanalytics/xapi/client/LRS.java

@@ -0,0 +1,95 @@
+package com.yetanalytics.xapi.client;
+
+import java.net.URI;
+
+/**
+ * Object for holding LRS connection details for StatementClient.
+ */
+public class LRS {
+
+    /**
+     * Constructor to create an LRS object with specific connection params
+     * 
+     * @param host Host for LRS. Should include path, e.g. 'http://lrs.yetanalytics.com/xapi'
+     * @param key Key for LRS credentials
+     * @param secret Secret for LRS credentials
+     * @param batchSize Optional post batch size, defaults to 50
+     */
+    public LRS (String host, String key, String secret, Integer batchSize){
+
+        if(key == null || key.isEmpty())
+            throw new IllegalArgumentException(
+                "LRS auth key must be present.");
+        this.key = key;
+
+        if(key == null || key.isEmpty())
+            throw new IllegalArgumentException(
+                "LRS auth secret must be present.");
+        this.secret = secret;
+
+        //Host Validation
+        this.host = URI.create(host);
+        if (this.host.getPath() == null) {
+            throw new IllegalArgumentException(
+                "LRS host must have path prefix.");
+        } else if (!this.host.getPath().endsWith("/")) { 
+            this.host = URI.create(host.concat("/"));
+        }
+
+        if(batchSize != null && batchSize > 0){
+            this.batchSize = batchSize;
+        }
+    }
+
+    /**
+     * Constructor to create an LRS object with specific connection params
+     * 
+     * @param host Host for LRS. Should include path, e.g. 'http://lrs.yetanalytics.com/xapi'
+     * @param key Key for LRS credentials
+     * @param secret Secret for LRS credentials
+     */
+    public LRS (String host, String key, String secret){
+        this(host, key, secret, null);
+    }
+
+    private URI host;
+
+    private String key;
+
+    private String secret;
+
+    private Integer batchSize = 50;
+
+    public URI getHost() {
+        return host;
+    }
+
+    public void setHost(URI host) {
+        this.host = host;
+    }
+
+    public String getKey() {
+        return key;
+    }
+
+    public void setKey(String key) {
+        this.key = key;
+    }
+
+    public String getSecret() {
+        return secret;
+    }
+
+    public void setSecret(String secret) {
+        this.secret = secret;
+    }
+
+    public Integer getBatchSize() {
+        return batchSize;
+    }
+
+    public void setBatchSize(Integer batchSize) {
+        this.batchSize = batchSize;
+    }
+
+}

src/main/java/com/yetanalytics/xapi/client/StatementClient.java

@@ -0,0 +1,193 @@
+package com.yetanalytics.xapi.client;
+
+import java.io.IOException;
+import java.net.URI;
+import java.util.ArrayList;
+import java.util.Base64;
+import java.util.List;
+import java.util.UUID;
+
+import org.apache.http.Header;
+import org.apache.http.HttpHeaders;
+import org.apache.http.ParseException;
+import org.apache.http.client.ClientProtocolException;
+import org.apache.http.client.methods.CloseableHttpResponse;
+import org.apache.http.client.methods.HttpGet;
+import org.apache.http.client.methods.HttpPost;
+import org.apache.http.entity.StringEntity;
+import org.apache.http.impl.client.CloseableHttpClient;
+import org.apache.http.impl.client.HttpClients;
+import org.apache.http.message.BasicHeader;
+import org.apache.http.util.EntityUtils;
+
+import com.fasterxml.jackson.core.type.TypeReference;
+import com.google.common.collect.Lists;
+import com.yetanalytics.xapi.client.filters.StatementFilters;
+import com.yetanalytics.xapi.exception.StatementClientException;
+import com.yetanalytics.xapi.model.Statement;
+import com.yetanalytics.xapi.model.StatementResult;
+import com.yetanalytics.xapi.util.Mapper;
+
+/**
+ * Minimal xAPI Client featuring GET and POST Operations for LRS interop.
+ */
+public class StatementClient {
+
+    private static final String STATEMENT_ENDPOINT = "statements";
+
+    private LRS lrs;
+    private CloseableHttpClient client;
+
+    /**
+     * Constructor to create an xAPI Client
+     * 
+     * @param lrs The Learning Record store to connect to
+     */
+    public StatementClient (LRS lrs) {
+        this.lrs = lrs;
+
+        String encodedCreds = Base64.getEncoder().encodeToString(
+            String.format("%s:%s", lrs.getKey(), lrs.getSecret()).getBytes());
+
+        //TODO: Version headers
+        List<Header> headers = new ArrayList<Header>();
+        headers.add(new BasicHeader("X-Experience-API-Version","1.0.3"));
+        headers.add(new BasicHeader(HttpHeaders.CONTENT_TYPE, "application/json"));
+        headers.add(new BasicHeader(HttpHeaders.ACCEPT, "application/json"));
+        headers.add(new BasicHeader("Authorization",
+            String.format("Basic %s", encodedCreds)));
+
+        this.client = HttpClients.custom()
+            .setDefaultHeaders(headers)
+            .build();
+    }
+
+    private List<UUID> doPost(List<Statement> statements, URI endpoint) 
+            throws ParseException, IOException {
+        HttpPost post = new HttpPost(endpoint);
+        post.setEntity(new StringEntity(
+            Mapper.getMapper().writeValueAsString(statements)));
+
+        CloseableHttpResponse response = client.execute(post);
+
+        if (response.getStatusLine().getStatusCode() == 200) {
+            String responseBody = EntityUtils.toString(response.getEntity());
+            return Mapper.getMapper().readValue(
+                responseBody, 
+                new TypeReference<List<UUID>>(){});
+        } else {
+            throw new StatementClientException(String.format(
+                "Error, Non-200 Status. Received: %s",
+                response.getStatusLine().getStatusCode()));
+        }
+    }
+
+    /**
+     * Method to post a single xAPI Statement to an LRS.
+     * 
+     * @param stmt Statement to post to LRS
+     * @return List of IDs for created statement(s) from LRS
+     */
+    public List<UUID> postStatement(Statement stmt) {
+        return postStatements(new ArrayList<>(List.of(stmt)));
+    }
+
+    /**
+     * Method to post a List of xAPI Statements to an LRS.
+     * 
+     * @param stmts Statements to post to LRS
+     * @return List of IDs for created statement(s) from LRS
+     */
+    public List<UUID> postStatements(List<Statement> stmts) {
+        try {
+            List<UUID> result = new ArrayList<UUID>();
+            for (List<Statement> p : Lists.partition(stmts, lrs.getBatchSize())) {
+                result.addAll(doPost(p, lrs.getHost().resolve(STATEMENT_ENDPOINT)));
+            }
+            return result;
+        } catch (ParseException | IOException e) {
+            throw new StatementClientException("Error posting Statements", e);
+        }
+    }
+
+    private StatementResult doGetStatementResult(URI endpoint) 
+            throws ClientProtocolException, IOException {
+        HttpGet get = new HttpGet(endpoint);
+        CloseableHttpResponse response = client.execute(get);
+
+        if (response.getStatusLine().getStatusCode() == 200) {
+            String responseBody = EntityUtils.toString(response.getEntity());
+            return Mapper.getMapper().readValue(responseBody, StatementResult.class);
+        } else {
+            throw new StatementClientException(String.format(
+                "Error, Non-200 Status. Received: %s",
+                response.getStatusLine().getStatusCode()));
+        }
+    }
+
+    private Statement doGetStatement(URI endpoint) 
+            throws ClientProtocolException, IOException {
+        HttpGet get = new HttpGet(endpoint);
+        CloseableHttpResponse response = client.execute(get);
+
+        if (response.getStatusLine().getStatusCode() == 200) {
+            String responseBody = EntityUtils.toString(response.getEntity());
+            return Mapper.getMapper().readValue(responseBody, Statement.class);
+        } else {
+            throw new StatementClientException(String.format(
+                "Error, Non-200 Status. Received: %s",
+                response.getStatusLine().getStatusCode()));
+        }
+    }
+
+    private URI resolveMore(URI moreLink) {
+        if (moreLink == null || moreLink.toString().equals("")) 
+            return null;
+        URI uri = lrs.getHost().resolve(STATEMENT_ENDPOINT);
+        return uri.resolve(moreLink.toString());
+    }
+
+    /**
+     * Method to get Statements from LRS
+     * 
+     * @param filters StatementFilters object to filter the query.
+     * @return All statements that match filter
+     */
+    public List<Statement> getStatements(StatementFilters filters) {
+        List<Statement> statements = new ArrayList<Statement>();
+
+        URI target = lrs.getHost().resolve(STATEMENT_ENDPOINT);
+        if (filters != null) {
+            target = filters.addQueryToUri(target);
+        }
+
+        try {
+            while(target != null) {
+                if (filters != null && 
+                        (filters.getStatementId() != null 
+                        || filters.getVoidedStatementId() != null)) {
+                    statements.add(doGetStatement(target));
+                    target = null;
+                } else {
+                    StatementResult result = doGetStatementResult(target);
+                    statements.addAll(result.getStatements());
+                    target = resolveMore(result.getMore());
+                }
+            }
+
+        } catch (IOException e) {
+            throw new StatementClientException("Error getting Statements", e);
+        }
+        return statements;
+    }
+
+    /**
+     * Method to get Statements from LRS with no filters
+     * 
+     * @return All statements
+     */
+    public List<Statement> getStatements() {
+        return getStatements(null);
+    }
+
+}