Ant example source code file (Cab.java)

This example Ant source code file (Cab.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Ant tags/keywords

buildexception, buildexception, exectask, file, file, fileset, io, ioexception, logoutputstream, problem, string, string, stringbuffer, util, vector, vector

The Cab.java source code

/*
 *  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.tools.ant.taskdefs.optional;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.Enumeration;
import java.util.Vector;
import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.DirectoryScanner;
import org.apache.tools.ant.Project;
import org.apache.tools.ant.taskdefs.ExecTask;
import org.apache.tools.ant.taskdefs.Execute;
import org.apache.tools.ant.taskdefs.LogOutputStream;
import org.apache.tools.ant.taskdefs.MatchingTask;
import org.apache.tools.ant.taskdefs.StreamPumper;
import org.apache.tools.ant.taskdefs.condition.Os;
import org.apache.tools.ant.types.FileSet;
import org.apache.tools.ant.util.FileUtils;


/**
 * Create a CAB archive.
 *
 */

public class Cab extends MatchingTask {

    private File cabFile;
    private File baseDir;
    private Vector filesets = new Vector();
    private boolean doCompress = true;
    private boolean doVerbose = false;
    private String cmdOptions;

    // CheckStyle:VisibilityModifier OFF - bc
    protected String archiveType = "cab";
    // CheckStyle:VisibilityModifier ON

    private static final FileUtils FILE_UTILS = FileUtils.getFileUtils();

    /**
     * The name/location of where to create the .cab file.
     * @param cabFile the location of the cab file.
     */
    public void setCabfile(File cabFile) {
        this.cabFile = cabFile;
    }

    /**
     * Base directory to look in for files to CAB.
     * @param baseDir base directory for files to cab.
     */
    public void setBasedir(File baseDir) {
        this.baseDir = baseDir;
    }

    /**
     * If true, compress the files otherwise only store them.
     * @param compress a <code>boolean value.
     */
    public void setCompress(boolean compress) {
        doCompress = compress;
    }

    /**
     * If true, display cabarc output.
     * @param verbose a <code>boolean value.
     */
    public void setVerbose(boolean verbose) {
        doVerbose = verbose;
    }

    /**
     * Sets additional cabarc options that are not supported directly.
     * @param options cabarc command line options.
     */
    public void setOptions(String options) {
        cmdOptions = options;
    }

    /**
     * Adds a set of files to archive.
     * @param set a set of files to archive.
     */
    public void addFileset(FileSet set) {
        if (filesets.size() > 0) {
            throw new BuildException("Only one nested fileset allowed");
        }
        filesets.addElement(set);
    }

    /*
     * I'm not fond of this pattern: "sub-method expected to throw
     * task-cancelling exceptions".  It feels too much like programming
     * for side-effects to me...
     */
    /**
     * Check if the attributes and nested elements are correct.
     * @throws BuildException on error.
     */
    protected void checkConfiguration() throws BuildException {
        if (baseDir == null && filesets.size() == 0) {
            throw new BuildException("basedir attribute or one "
                                     + "nested fileset is required!",
                                     getLocation());
        }
        if (baseDir != null && !baseDir.exists()) {
            throw new BuildException("basedir does not exist!", getLocation());
        }
        if (baseDir != null && filesets.size() > 0) {
            throw new BuildException(
                "Both basedir attribute and a nested fileset is not allowed");
        }
        if (cabFile == null) {
            throw new BuildException("cabfile attribute must be set!",
                                     getLocation());
        }
    }

    /**
     * Create a new exec delegate.  The delegate task is populated so that
     * it appears in the logs to be the same task as this one.
     * @return the delegate.
     * @throws BuildException on error.
     */
    protected ExecTask createExec() throws BuildException {
        ExecTask exec = new ExecTask(this);
        return exec;
    }

    /**
     * Check to see if the target is up to date with respect to input files.
     * @param files the list of files to check.
     * @return true if the cab file is newer than its dependents.
     */
    protected boolean isUpToDate(Vector files) {
        boolean upToDate = true;
        for (int i = 0; i < files.size() && upToDate; i++) {
            String file = files.elementAt(i).toString();
            if (FILE_UTILS.resolveFile(baseDir, file).lastModified()
                    > cabFile.lastModified()) {
                upToDate = false;
            }
        }
        return upToDate;
    }

    /**
     * Creates a list file.  This temporary file contains a list of all files
     * to be included in the cab, one file per line.
     *
     * <p>This method expects to only be called on Windows and thus
     * quotes the file names.</p>
     * @param files the list of files to use.
     * @return the list file created.
     * @throws IOException if there is an error.
     */
    protected File createListFile(Vector files)
        throws IOException {
        File listFile = FILE_UTILS.createTempFile("ant", "", null);
        listFile.deleteOnExit();

        PrintWriter writer = new PrintWriter(new FileOutputStream(listFile));

        int size = files.size();
        for (int i = 0; i < size; i++) {
            writer.println('\"' + files.elementAt(i).toString() + '\"');
        }
        writer.close();

        return listFile;
    }

    /**
     * Append all files found by a directory scanner to a vector.
     * @param files the vector to append the files to.
     * @param ds the scanner to get the files from.
     */
    protected void appendFiles(Vector files, DirectoryScanner ds) {
        String[] dsfiles = ds.getIncludedFiles();

        for (int i = 0; i < dsfiles.length; i++) {
            files.addElement(dsfiles[i]);
        }
    }

    /**
     * Get the complete list of files to be included in the cab.  Filenames
     * are gathered from the fileset if it has been added, otherwise from the
     * traditional include parameters.
     * @return the list of files.
     * @throws BuildException if there is an error.
     */
    protected Vector getFileList() throws BuildException {
        Vector files = new Vector();

        if (baseDir != null) {
            // get files from old methods - includes and nested include
            appendFiles(files, super.getDirectoryScanner(baseDir));
        } else {
            FileSet fs = (FileSet) filesets.elementAt(0);
            baseDir = fs.getDir();
            appendFiles(files, fs.getDirectoryScanner(getProject()));
        }

        return files;
    }

    /**
     * execute this task.
     * @throws BuildException on error.
     */
    public void execute() throws BuildException {

        checkConfiguration();

        Vector files = getFileList();

        // quick exit if the target is up to date
        if (isUpToDate(files)) {
            return;
        }

        log("Building " + archiveType + ": " + cabFile.getAbsolutePath());

        if (!Os.isFamily("windows")) {
            log("Using listcab/libcabinet", Project.MSG_VERBOSE);

            StringBuffer sb = new StringBuffer();

            Enumeration fileEnum = files.elements();

            while (fileEnum.hasMoreElements()) {
                sb.append(fileEnum.nextElement()).append("\n");
            }
            sb.append("\n").append(cabFile.getAbsolutePath()).append("\n");

            try {
                Process p = Execute.launch(getProject(),
                                           new String[] {"listcab"}, null,
                                           baseDir != null ? baseDir
                                                   : getProject().getBaseDir(),
                                           true);
                OutputStream out = p.getOutputStream();

                // Create the stream pumpers to forward listcab's stdout and stderr to the log
                // note: listcab is an interactive program, and issues prompts for every new line.
                //       Therefore, make it show only with verbose logging turned on.
                LogOutputStream outLog = new LogOutputStream(this, Project.MSG_VERBOSE);
                LogOutputStream errLog = new LogOutputStream(this, Project.MSG_ERR);
                StreamPumper    outPump = new StreamPumper(p.getInputStream(), outLog);
                StreamPumper    errPump = new StreamPumper(p.getErrorStream(), errLog);

                // Pump streams asynchronously
                (new Thread(outPump)).start();
                (new Thread(errPump)).start();

                out.write(sb.toString().getBytes());
                out.flush();
                out.close();

                int result = -99; // A wild default for when the thread is interrupted

                try {
                    // Wait for the process to finish
                    result = p.waitFor();

                    // Wait for the end of output and error streams
                    outPump.waitFor();
                    outLog.close();
                    errPump.waitFor();
                    errLog.close();
                } catch (InterruptedException ie) {
                    log("Thread interrupted: " + ie);
                }

                // Informative summary message in case of errors
                if (Execute.isFailure(result)) {
                    log("Error executing listcab; error code: " + result);
                }
            } catch (IOException ex) {
                String msg = "Problem creating " + cabFile + " " + ex.getMessage();
                throw new BuildException(msg, getLocation());
            }
        } else {
            try {
                File listFile = createListFile(files);
                ExecTask exec = createExec();
                File outFile = null;

                // die if cabarc fails
                exec.setFailonerror(true);
                exec.setDir(baseDir);

                if (!doVerbose) {
                    outFile = FILE_UTILS.createTempFile("ant", "", null);
                    outFile.deleteOnExit();
                    exec.setOutput(outFile);
                }

                exec.setExecutable("cabarc");
                exec.createArg().setValue("-r");
                exec.createArg().setValue("-p");

                if (!doCompress) {
                    exec.createArg().setValue("-m");
                    exec.createArg().setValue("none");
                }

                if (cmdOptions != null) {
                    exec.createArg().setLine(cmdOptions);
                }

                exec.createArg().setValue("n");
                exec.createArg().setFile(cabFile);
                exec.createArg().setValue("@" + listFile.getAbsolutePath());

                exec.execute();

                if (outFile != null) {
                    outFile.delete();
                }

                listFile.delete();
            } catch (IOException ioe) {
                String msg = "Problem creating " + cabFile + " " + ioe.getMessage();
                throw new BuildException(msg, getLocation());
            }
        }
    }
}