OutOfMemoryError problem

Hi,

I am a user of cruisecontrol ( continuous integration server). As long
as I have used it I have had problems with
java.lang.OutOfMemoryError's. I have gotten numerous ideas on how to
handle it. Some
resonable and some more unrealistic. However lately I dicided that I
need to dig deeper into this.
I use two ways to perform build and test. Both ways use the same 'ant'
and the same 'build file'.
The difference is in how the build is triggered.

Shell script
=========

Here I use a shell script to start ant.
java -Xms512M -Xmx756M -classpath .......

Cruisecontrol
==========

Here I start cruisecontrol ( a java program) that starts ant.
I set Xms and Xmx for cruisecontrol as well as ant.

When I execute the shell script the 'junit' and 'junitreport' tasks
execute nicely.

On the other hand when I execute 'cruisecontrol' I get a
java.lang.OutOfMemoryError when I execute the 'junit-report'.

Trace:
--------
BUILD FAILED
 java.lang.OutOfMemoryError
         at
 org.apache.tools.ant.Project.executeSortedTargets(Project.java:1225)
         at
org.apache.tools.ant.Project.executeTarget(Project.java:1185)
         at

org.apache.tools.ant.helper.DefaultExecutor.executeTargets(DefaultExecut
 or.java:40)
         at
 org.apache.tools.ant.Project.executeTargets(Project.java:1068)
         at org.apache.tools.ant.Main.runBuild(Main.java:668)
         at org.apache.tools.ant.Main.startAnt(Main.java:187)
         at org.apache.tools.ant.launch.Launcher.run(Launcher.java:246)
         at org.apache.tools.ant.launch.Launcher.main(Launcher.java:67)
 Caused by: java.lang.OutOfMemoryError
 --- Nested Exception ---
 java.lang.OutOfMemoryError

I did some investigation in ant ( source code ) and found out the each
junit test suite result ( xml-file) is merged into one big xml file.

There are two steps in the code. Step 1 works ok! Step 2 is failing
siince the big merged file is not complete.  Could it be something with
the jvm?

All hints are welcome.

cheers,

//mikael

Step 1 - creating the dom document
-------------------------------------------

protected Element createDocument() {
        // create the dom tree
        DocumentBuilder builder = getDocumentBuilder();
        Document doc = builder.newDocument();
        Element rootElement = doc.createElement(TESTSUITES);
        doc.appendChild(rootElement);

        generatedId = 0;

        // get all files and add them to the document
        File[] files = getFiles();
        for (int i = 0; i < files.length; i++) {
            File file = files[i];
            try {
                log("Parsing file: '" + file + "'",
Project.MSG_VERBOSE);
                if(file.length()>0) {
                    Document testsuiteDoc
                            =
builder.parse(FileUtils.getFileUtils().toURI(files[i].getAbsolutePath()));
                    Element elem = testsuiteDoc.getDocumentElement();
                    // make sure that this is REALLY a testsuite.
                    if (TESTSUITE.equals(elem.getNodeName())) {
                        addTestSuite(rootElement, elem);
                        generatedId++;
                    } else {
                        //wrong root element name
                        // issue a warning.
                        log("the file " + file
                                + WARNING_INVALID_ROOT_ELEMENT,
                                Project.MSG_WARN);
                    }
                } else {
                    log("the file " + file
                            + WARNING_EMPTY_FILE,
                            Project.MSG_WARN);
                }
            } catch (SAXException e) {
                // a testcase might have failed and write a zero-length
document,
                // It has already failed, but hey.... mm. just put a
warning
                log("The file " + file + WARNING_IS_POSSIBLY_CORRUPTED,
Project.MSG_WARN);
                log(StringUtils.getStackTrace(e), Project.MSG_DEBUG);
            } catch (IOException e) {
                log("Error while accessing file " + file + ": "
                    + e.getMessage(), Project.MSG_ERR);
            }
        }
        return rootElement;
    }


Step 2 - write the DOM Tree to file
----------------------------------------

protected void writeDOMTree(Document doc, File file) throws IOException
{
        OutputStream out = null;
        PrintWriter wri = null;
        try {
            out = new BufferedOutputStream(new FileOutputStream(file));
            wri = new PrintWriter(new OutputStreamWriter(out, "UTF8"));
            wri.write("<?xml version=\"1.0\" encoding=\"UTF-8\" ?>\n");
            (new DOMElementWriter()).write(doc.getDocumentElement(),
wri, 0, "  ");
            wri.flush();
            // writers do not throw exceptions, so check for them.
            if (wri.checkError()) {
                throw new IOException("Error while writing DOM
content");
            }
        } finally {
            FileUtils.close(wri);
            FileUtils.close(out);
        }
    }