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. */ /* $Id: Main.java 985537 2010-08-14 17:17:00Z jeremias $ */ package org.apache.fop.cli; import java.io.File; import java.io.FileFilter; import java.io.OutputStream; import java.lang.reflect.Method; import java.net.MalformedURLException; import java.net.URL; import java.util.List; import org.apache.commons.io.IOUtils; import org.apache.fop.apps.FOUserAgent; import org.apache.fop.apps.MimeConstants; /** * Main command-line class for Apache FOP. */ public final class Main { private Main() { } /** * @return the list of URLs to all libraries. * @throws MalformedURLException In case there is a problem converting java.io.File * instances to URLs. */ public static URL[] getJARList() throws MalformedURLException { String fopHome = System.getProperty("fop.home"); File baseDir; if (fopHome != null) { baseDir = new File(fopHome).getAbsoluteFile(); } else { baseDir = new File(".").getAbsoluteFile().getParentFile(); } File buildDir; if ("build".equals(baseDir.getName())) { buildDir = baseDir; baseDir = baseDir.getParentFile(); } else { buildDir = new File(baseDir, "build"); } File fopJar = new File(buildDir, "fop.jar"); if (!fopJar.exists()) { fopJar = new File(baseDir, "fop.jar"); } if (!fopJar.exists()) { throw new RuntimeException( "fop.jar not found in directory: " + baseDir.getAbsolutePath() + " (or below)"); } List jars = new java.util.ArrayList(); jars.add(fopJar.toURI().toURL()); File[] files; FileFilter filter = new FileFilter() { public boolean accept(File pathname) { return pathname.getName().endsWith(".jar"); } }; File libDir = new File(baseDir, "lib"); if (!libDir.exists()) { libDir = baseDir; } files = libDir.listFiles(filter); if (files != null) { for (int i = 0, size = files.length; i < size; i++) { jars.add(files[i].toURI().toURL()); } } String optionalLib = System.getProperty("fop.optional.lib"); if (optionalLib != null) { files = new File(optionalLib).listFiles(filter); if (files != null) { for (int i = 0, size = files.length; i < size; i++) { jars.add(files[i].toURI().toURL()); } } } URL[] urls = (URL[]) jars.toArray(new URL[jars.size()]); /* for (int i = 0, c = urls.length; i < c; i++) { System.out.println(urls[i]); }*/ return urls; } /** * @return true if FOP's dependecies are available in the current ClassLoader setup. */ public static boolean checkDependencies() { try { //System.out.println(Thread.currentThread().getContextClassLoader()); Class clazz = Class.forName("org.apache.commons.io.IOUtils"); if (clazz != null) { clazz = Class.forName("org.apache.avalon.framework.configuration.Configuration"); } return (clazz != null); } catch (Exception e) { return false; } } /** * Dynamically builds a ClassLoader and executes FOP. * @param args command-line arguments */ public static void startFOPWithDynamicClasspath(String[] args) { try { URL[] urls = getJARList(); //System.out.println("CCL: " // + Thread.currentThread().getContextClassLoader().toString()); ClassLoader loader = new java.net.URLClassLoader(urls, null); Thread.currentThread().setContextClassLoader(loader); Class clazz = Class.forName("org.apache.fop.cli.Main", true, loader); //System.out.println("CL: " + clazz.getClassLoader().toString()); Method mainMethod = clazz.getMethod("startFOP", new Class[] { String[].class }); mainMethod.invoke(null, new Object[] { args }); } catch (Exception e) { System.err.println("Unable to start FOP:"); e.printStackTrace(); System.exit(-1); } } /** * Executes FOP with the given arguments. If no argument is provided, returns its * version number as well as a short usage statement; if '-v' is provided, returns its * version number alone; if '-h' is provided, returns its short help message. * * @param args command-line arguments */ public static void startFOP(String[] args) { //System.out.println("static CCL: " // + Thread.currentThread().getContextClassLoader().toString()); //System.out.println("static CL: " + Fop.class.getClassLoader().toString()); CommandLineOptions options = null; FOUserAgent foUserAgent = null; OutputStream out = null; try { options = new CommandLineOptions(); if (!options.parse(args)) { System.exit(0); } foUserAgent = options.getFOUserAgent(); String outputFormat = options.getOutputFormat(); try { if (options.getOutputFile() != null) { out = new java.io.BufferedOutputStream(new java.io.FileOutputStream(options.getOutputFile())); foUserAgent.setOutputFile(options.getOutputFile()); } else if (options.isOutputToStdOut()) { out = new java.io.BufferedOutputStream(System.out); } if (!MimeConstants.MIME_XSL_FO.equals(outputFormat)) { options.getInputHandler().renderTo(foUserAgent, outputFormat, out); } else { options.getInputHandler().transformTo(out); } } finally { IOUtils.closeQuietly(out); } // System.exit(0) called to close AWT/SVG-created threads, if any. // AWTRenderer closes with window shutdown, so exit() should not // be called here if (!MimeConstants.MIME_FOP_AWT_PREVIEW.equals(outputFormat)) { System.exit(0); } } catch (Exception e) { if (options != null) { options.getLogger().error("Exception", e); if (options.getOutputFile() != null) { options.getOutputFile().delete(); } } System.exit(1); } } /** * The main routine for the command line interface * @param args the command line parameters */ public static void main(String[] args) { if (checkDependencies()) { startFOP(args); } else { startFOPWithDynamicClasspath(args); } } }