Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.apache.commons.javaflow.ant; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.IOException; import java.util.jar.JarInputStream; import java.util.jar.JarOutputStream; import org.apache.commons.javaflow.bytecode.transformation.ResourceTransformer; import org.apache.commons.javaflow.bytecode.transformation.asm.AsmClassTransformer; import org.apache.commons.javaflow.utils.RewritingUtils; import org.apache.tools.ant.BuildException; import org.apache.tools.ant.DirectoryScanner; import org.apache.tools.ant.Project; import org.apache.tools.ant.taskdefs.MatchingTask; import org.apache.tools.ant.types.FileSet; /** * Ant task that enhances class files with javaflow instrumentation. */ public class AntRewriteTask extends MatchingTask { private ResourceTransformer transformer; private File dstDir; private File srcDir; /** * Directory to which the transformed files will be written. * This can be the same as the source directory. */ public void setDestdir(final File pFile) { dstDir = pFile; } /** * Directory from which the input files are read. * This and the inherited {@link MatchingTask} forms an implicit * {@link FileSet}. */ public void setSrcDir(final File pFile) { srcDir = pFile; fileset.setDir(srcDir); } /** * Sets the transformer to use. * * <p> * This option is unpublished, because in a long run we'll * likely to just focus on one transformer and get rid * of the other (and this option will be removed then.) * * @param name * "ASM". Case insensitive. */ public void setMode(String name) { if (name.equalsIgnoreCase("asm")) { transformer = new AsmClassTransformer(); } else { throw new BuildException("Unrecognized mode: " + name); } } /** * Check that all required attributes have been set and nothing * silly has been entered. * * @since Ant 1.5 */ protected void checkParameters() throws BuildException { checkDir(srcDir, "srcDir"); checkDir(dstDir, "dstDir"); } private void checkDir(final File pDir, final String pDescription) { if (pDir == null) { throw new BuildException("no " + pDescription + " directory is specified", getLocation()); } if (!pDir.exists()) { throw new BuildException(pDescription + " directory \"" + pDir + "\" does not exist", getLocation()); } if (!pDir.isDirectory()) { throw new BuildException(pDescription + " directory \"" + pDir + "\" is not a directory", getLocation()); } } public void execute() throws BuildException { final DirectoryScanner ds = fileset.getDirectoryScanner(getProject()); final String[] fileNames = ds.getIncludedFiles(); if (transformer == null) { transformer = new AsmClassTransformer(); } try { for (final String fileName : fileNames) { final File source = new File(srcDir, fileName); final File destination = new File(dstDir, fileName); if (!destination.getParentFile().exists()) { log("Creating dir: " + destination.getParentFile(), Project.MSG_VERBOSE); destination.getParentFile().mkdirs(); } if (source.lastModified() < destination.lastModified()) { log("Omitting " + source + " as " + destination + " is up to date", Project.MSG_VERBOSE); continue; } if (fileName.endsWith(".class")) { log("Rewriting " + source + " to " + destination, Project.MSG_VERBOSE); // System.out.println("Rewriting " + source); RewritingUtils.rewriteClassFile(source, transformer, destination); } if (fileName.endsWith(".jar") || fileName.endsWith(".ear") || fileName.endsWith(".zip") || fileName.endsWith(".war")) { log("Rewriting " + source + " to " + destination, Project.MSG_VERBOSE); RewritingUtils.rewriteJar(new JarInputStream(new FileInputStream(source)), transformer, new JarOutputStream(new FileOutputStream(destination))); } } } catch (IOException e) { throw new BuildException(e); } } }