Fixed #172

 o Fixed implementation of BuildWithDetails.getCauses() to
   prevent NPE's.

ReleaseNotes.md

@@ -21,6 +21,12 @@
    * maven-resources-plugin to 3.0.0
    * maven-jar-plugin to 3.0.0
 
+  [Fixed issue 172][issue-172]
+
+  The implementation `BuildWithDetails.getCauses()` could cause an 
+  NPE which now has been imroved to prevent it. Thanks for hint
+  which brought me to reconsider the implementation.
+
   [Fixed issue 162][issue-162]
 
   Serveral issues fixed related to using logging framework 
@@ -508,6 +514,7 @@ TestReport testReport = mavenJob.getLastSuccessfulBuild().getTestReport();
 [issue-162]: https://github.com/jenkinsci/java-client-api/issues/162
 [issue-165]: https://github.com/jenkinsci/java-client-api/issues/165
 [issue-167]: https://github.com/jenkinsci/java-client-api/issues/167
+[issue-172]: https://github.com/jenkinsci/java-client-api/issues/172
 [pull-123]: https://github.com/jenkinsci/java-client-api/pull/123
 [pull-149]: https://github.com/jenkinsci/java-client-api/pull/149
 [pull-158]: https://github.com/jenkinsci/java-client-api/pull/158

jenkins-client-it-docker/src/test/java/com/offbytwo/jenkins/integration/Constant.java

@@ -10,6 +10,7 @@ public final class Constant {
      * At the moment it is solved by a profile in pom..but could that somehow 
      * identified by docker itself ?
      */
-    public static final URI JENKINS_URI = URI.create(System.getProperty("docker.container.network"));
+//    public static final URI JENKINS_URI = URI.create(System.getProperty("docker.container.network"));
+    public static final URI JENKINS_URI = URI.create("http://192.168.99.100:8080/");
 
 }

jenkins-client-it-docker/src/test/java/com/offbytwo/jenkins/integration/NoExecutorStartedGetJobDetailsIT.java

@@ -0,0 +1,46 @@
+package com.offbytwo.jenkins.integration;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.io.IOException;
+import java.util.List;
+
+import org.testng.annotations.BeforeMethod;
+import org.testng.annotations.Test;
+
+import com.offbytwo.jenkins.model.BuildCause;
+import com.offbytwo.jenkins.model.BuildWithDetails;
+import com.offbytwo.jenkins.model.JobWithDetails;
+
+@Test( groups = { Groups.NO_EXECUTOR_GROUP } )
+public class NoExecutorStartedGetJobDetailsIT
+    extends AbstractJenkinsIntegrationCase
+{
+
+    private JobWithDetails job;
+
+    @BeforeMethod
+    public void beforeMethod()
+        throws IOException
+    {
+        job = jenkinsServer.getJob( "test" );
+    }
+
+    @Test
+    public void shouldCheckTheBuildCause() throws IOException
+    {
+	BuildWithDetails details = job.getFirstBuild().details();
+	List<BuildCause> causes = details.getCauses();
+        assertThat(causes).hasSize(1);
+        BuildCause buildCause = causes.get(0);
+
+        assertThat(buildCause.getShortDescription()).isEqualTo("Started by user anonymous");
+        assertThat(buildCause.getUserName()).isEqualTo("anonymous");
+        assertThat(buildCause.getUpstreamBuild()).isEqualTo(0);
+        assertThat(buildCause.getUpstreamProject()).isNull();
+        assertThat(buildCause.getUserId()).isNull();
+
+    }
+
+
+}

jenkins-client/src/main/java/com/offbytwo/jenkins/model/BuildCause.java

@@ -14,6 +14,9 @@ public class BuildCause {
 
     public BuildCause() {
         this.upstreamBuild = new Integer(0);
+        //TODO: Think about initialization of the other
+        // attributes as well.
+        // userId = StringConstant.EMPTY;
     }
 
     public String getShortDescription() {

jenkins-client/src/main/java/com/offbytwo/jenkins/model/BuildWithDetails.java

@@ -7,6 +7,7 @@
 package com.offbytwo.jenkins.model;
 
 import com.google.common.base.Predicate;
+import com.google.common.base.Strings;
 
 import java.io.IOException;
 import java.io.InputStream;
@@ -16,23 +17,29 @@
 
 import static com.google.common.collect.Collections2.filter;
 
+/**
+ * This class represents build information with
+ * details about what has been done like
+ * duration start and of course the build result.
+ *
+ */
 public class BuildWithDetails extends Build {
 
-    List actions; // Should be improved.
-    boolean building;
-    String description;
-    long duration;
-    long estimatedDuration;
-    String fullDisplayName;
-    String id;
-    long timestamp;
-    BuildResult result;
-    List<Artifact> artifacts;
-    String consoleOutputText;
-    String consoleOutputHtml;
-    BuildChangeSet changeSet;
-    String builtOn;
-    List<BuildChangeSetAuthor> culprits;
+    private List actions; // TODO: Should be improved.
+    private boolean building;
+    private String description;
+    private long duration;
+    private long estimatedDuration;
+    private String fullDisplayName;
+    private String id;
+    private long timestamp;
+    private BuildResult result;
+    private List<Artifact> artifacts;
+    private String consoleOutputText;
+    private String consoleOutputHtml;
+    private BuildChangeSet changeSet;
+    private String builtOn;
+    private List<BuildChangeSetAuthor> culprits;
 
     public List<Artifact> getArtifacts() {
         return artifacts;
@@ -61,21 +68,51 @@ public boolean apply(Map<String, Object> action) {
                     .get("causes");
             for (Map<String, Object> cause : causes_blob) {
 
-                BuildCause cause_object = new BuildCause();
-                cause_object.setShortDescription((String) cause.get("shortDescription"));
-                cause_object.setUpstreamBuild((Integer) cause.get("upstreamBuild"));
-                cause_object.setUpstreamProject((String) cause.get("upstreamProject"));
-                cause_object.setUpstreamUrl((String) cause.get("upstreamUrl"));
-                cause_object.setUserId((String) cause.get("userId"));
-                cause_object.setUserName((String) cause.get("userName"));
+                BuildCause convertToBuildCause = convertToBuildCause(cause);
 
-                result.add(cause_object);
+                result.add(convertToBuildCause);
             }
         }
 
         return result;
     }
 
+    private BuildCause convertToBuildCause(Map<String, Object> cause) {
+        BuildCause cause_object = new BuildCause();
+
+        //TODO: Think about it. Can this be done more simpler?
+	String description = (String) cause.get("shortDescription");
+	if (!Strings.isNullOrEmpty(description)) {
+	    cause_object.setShortDescription(description);
+	}
+
+	Integer upstreamBuild = (Integer) cause.get("upstreamBuild");
+	if (upstreamBuild != null) {
+	    cause_object.setUpstreamBuild(upstreamBuild);
+	}
+
+	String upstreamProject = (String) cause.get("upstreamProject");
+	if (!Strings.isNullOrEmpty(upstreamProject)) {
+	    cause_object.setUpstreamProject(upstreamProject);
+	}
+
+	String upstreamUrl = (String) cause.get("upstreamUrl");
+	if (!Strings.isNullOrEmpty(upstreamProject)) {
+	    cause_object.setUpstreamUrl(upstreamUrl);
+	}
+
+	String userId = (String) cause.get("userId");
+	if (!Strings.isNullOrEmpty(userId)) {
+	    cause_object.setUserId(userId);
+	}
+
+	String userName = (String) cause.get("userName");
+	if (!Strings.isNullOrEmpty(userName)) {
+	    cause_object.setUserName(userName);
+	}
+	return cause_object;
+    }
+
     public String getDescription() {
         return description;
     }
@@ -166,8 +203,7 @@ public void setCulprits(List<BuildChangeSetAuthor> culprits) {
 
     public InputStream downloadArtifact(Artifact a) throws IOException, URISyntaxException {
         // We can't just put the artifact's relative path at the end of the url
-        // string,
-        // as there could be characters that need to be escaped.
+        // string, as there could be characters that need to be escaped.
         URI uri = new URI(getUrl());
         String artifactPath = uri.getPath() + "artifact/" + a.getRelativePath();
         URI artifactUri = new URI(uri.getScheme(), uri.getUserInfo(), uri.getHost(), uri.getPort(), artifactPath, "",