Iterable<? extends File> getDefaultBootclasspath() { List<File> files = new ArrayList<>(); String javaversion = System.getProperty("java.version"); // $NON-NLS-1$ if (javaversion.length() > 3) javaversion = javaversion.substring(0, 3); long jdkLevel = CompilerOptions.versionToJdkLevel(javaversion); if (jdkLevel < ClassFileConstants.JDK1_6) { // wrong jdk - 1.6 or above is required return null; } for (String fileName : org.eclipse.jdt.internal.compiler.util.Util.collectFilesNames()) { files.add(new File(fileName)); } return files; }