Don't swallow the stack trace if a Java program throws an exception.

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@276233 13f79535-47bb-0310-9956-ffa450edef68

WHATSNEW

@@ -84,6 +84,9 @@ Fixed bugs:
 
 * NPE when running commons listener. Bugzilla Report 27373.
 
+* <java> swallowed the stack trace of exceptions thrown by the
+  executed program if run in the same VM.
+
 Other changes:
 --------------
 

docs/faq.html

@@ -341,6 +341,12 @@
         Why do my custom task containers see Unknown Elements in Ant 1.6
         - they worked in Ant 1.5?
       
+      </a></li>
+                <li><a href="#java.exception.stacktrace">
+  
+        The program I run via &lt;java&gt; throws an exception but I
+        can't seem to get the full stack trace.
+      
       </a></li>
             </ul>
     
@@ -1593,6 +1599,18 @@ mv /tmp/foo $ANT_HOME/bin/antRun
                         <p>
           This approach should work for ant1.5 and ant1.6.
         </p>
+                    <p class="faq">
+      <a name="java.exception.stacktrace"></a>
+      
+        The program I run via &lt;java&gt; throws an exception but I
+        can't seem to get the full stack trace.
+      
+    </p>
+                  <p>This is a know bug that has been fixed after the release of
+        Ant 1.6.1.</p>
+                        <p>As a workaround, run your &lt;java&gt; task with
+        <code>fork="true"</code> and Ant will display the full
+        trace.</p>
                     </div>
   </div>
 

src/main/org/apache/tools/ant/taskdefs/Java.java

@@ -19,6 +19,8 @@ package org.apache.tools.ant.taskdefs;
 
 import java.io.File;
 import java.io.IOException;
+import java.io.PrintWriter;
+import java.io.StringWriter;
 import java.util.Vector;
 import org.apache.tools.ant.BuildException;
 import org.apache.tools.ant.ExitException;
@@ -169,14 +171,14 @@ public class Java extends Task {
             if (failOnError) {
                 throw e;
             } else {
-                log(e.getMessage(), Project.MSG_ERR);
+                log(e);
                 return 0;
             }
         } catch (Throwable t) {
             if (failOnError) {
                 throw new BuildException(t);
             } else {
-                log(t.getMessage(), Project.MSG_ERR);
+                log(t);
                 return 0;
             }
         }
@@ -792,4 +794,14 @@ public class Java extends Task {
         return new ExecuteWatchdog(timeout.longValue());
     }
 
+    /**
+     * @since 1.6.2
+     */
+    private void log(Throwable t) {
+        StringWriter sw = new StringWriter();
+        PrintWriter w = new PrintWriter(sw);
+        t.printStackTrace(w);
+        w.close();
+        log(sw.toString(), Project.MSG_ERR);
+    }
 }

xdocs/faq.xml

@@ -1409,6 +1409,21 @@ mv /tmp/foo $ANT_HOME/bin/antRun
         </p>
       </answer>
     </faq>
+
+    <faq id="java.exception.stacktrace">
+      <question>
+        The program I run via &lt;java&gt; throws an exception but I
+        can't seem to get the full stack trace.
+      </question>
+      <answer>
+        <p>This is a know bug that has been fixed after the release of
+        Ant 1.6.1.</p>
+
+        <p>As a workaround, run your &lt;java&gt; task with
+        <code>fork="true"</code> and Ant will display the full
+        trace.</p>
+      </answer>
+    </faq>
   </faqsection>
 
 </document>