I have the following method that makes a HTTP Get request on a server an parses the response as Java source code. I m doing this for multiple files in the same time. This works quite well for the first few files, but after a certain amount of time I get an exception:

Exception in thread "main" java.lang.OutOfMemoryError: Java heap space

The exception is thrown in the line: jp.parse(new StringReader(responseString)); I think the problem is a memory leak, because the file I m trying to parse there isn t really big. Only a few dozen lines of code. But I can t find the cause for this exception. Any hints?

public void retrieveSourceCode() {
            try {
                System.out.println("Try to get: " + getSourceCodeURI());
                String responseString = RestServices.getInstance().sendGetRequestJsonTextToString(getSourceCodeURI());
                JavaSourceFactory jsf = new JavaSourceFactory();
                JavaParser jp = new JavaParser(jsf);
                jp.parse(new StringReader(responseString));
                Iterator<?> iterator = jsf.getJavaSources();
                while(iterator.hasNext()) {
                    JavaSource source =  ((JavaSource) iterator.next());
                    fileName = source.getQName().toString();
                    sourceCode = source.toString();
                }
            } catch (ClientProtocolException e) {
                fileName = "no file name";
                sourceCode = "no sourcecode available";
                e.printStackTrace();
            } catch (IOException e) {
                fileName = "no file name";
                sourceCode = "no sourcecode available";
                e.printStackTrace();
            } catch (RestServicesException e) {
                fileName = "no file name";
                sourceCode = "no sourcecode available";
                e.printStackTrace();
            } catch (RecognitionException e) {
                fileName = "no file name";
                sourceCode = "no sourcecode available";
                e.printStackTrace();
            } catch (TokenStreamException e) {
                fileName = "no file name";
                sourceCode = "no sourcecode available";
                e.printStackTrace();
            }

            if (before == null) {
                beforeSourceCode = "no before sourcecode available";
            } else {
                try {
                    String responseString = RestServices.getInstance().sendGetRequestJsonTextToString(getBeforeVersionURI());
                    JavaSourceFactory jsf = new JavaSourceFactory();
                    JavaParser jp = new JavaParser(jsf);
                    jp.parse(new StringReader(responseString));
                    Iterator<?> iterator = jsf.getJavaSources();
                    while(iterator.hasNext()) {
                        JavaSource source = (JavaSource) iterator.next();
                        beforeSourceCode = source.toString();
                    }
                } catch (ClientProtocolException e) {
                    beforeSourceCode = "no before sourcecode available";
                } catch (RecognitionException e) {
                    beforeSourceCode = "no before sourcecode available";
                    e.printStackTrace();
                } catch (TokenStreamException e) {
                    beforeSourceCode = "no before sourcecode available";
                    e.printStackTrace();
                } catch (IOException e) {
                    beforeSourceCode = "no before sourcecode available";
                    e.printStackTrace();
                } catch (RestServicesException e) {
                    beforeSourceCode = "no before sourcecode available";
                    e.printStackTrace();
                }
            }

            if (after == null) {
                afterSourceCode = "no after sourcecode available";
            } else {
                try {
                    String responseString = RestServices.getInstance().sendGetRequestJsonTextToString(getAfterVersionURI());
                    JavaSourceFactory jsf = new JavaSourceFactory();
                    JavaParser jp = new JavaParser(jsf);
                    jp.parse(new StringReader(responseString));
                    Iterator<?> iterator = jsf.getJavaSources();
                    while(iterator.hasNext()) {
                        JavaSource source = (JavaSource) iterator.next();
                        afterSourceCode = source.toString();
                    }
                } catch (ClientProtocolException e) {
                    afterSourceCode = "no after sourcecode available";
                } catch (RecognitionException e) {
                    afterSourceCode = "no after sourcecode available";
                    e.printStackTrace();
                } catch (TokenStreamException e) {
                    afterSourceCode = "no after sourcecode available";
                    e.printStackTrace();
                } catch (IOException e) {
                    afterSourceCode = "no after sourcecode available";
                    e.printStackTrace();
                } catch (RestServicesException e) {
                    afterSourceCode = "no after sourcecode available";
                    e.printStackTrace();
                }
            }

            getChangeSet().addAffectedFile(getFileName());
    }