Ant example source code file (Image.java)

This example Ant source code file (Image.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

arraylist, arraylist, buildexception, buildexception, error, file, file, fileoutputstream, fileset, io, specify, string, transformoperation, util, vector, vector

The Image.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.image;

import com.sun.media.jai.codec.FileSeekableStream;
import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.DirectoryScanner;
import org.apache.tools.ant.taskdefs.MatchingTask;
import org.apache.tools.ant.types.FileSet;
import org.apache.tools.ant.types.optional.image.Draw;
import org.apache.tools.ant.types.optional.image.ImageOperation;
import org.apache.tools.ant.types.optional.image.Rotate;
import org.apache.tools.ant.types.optional.image.Scale;
import org.apache.tools.ant.types.optional.image.TransformOperation;

import javax.media.jai.JAI;
import javax.media.jai.PlanarImage;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.Vector;

/**
 * A MatchingTask which relies on <a
 * href="http://java.sun.com/products/java-media/jai">JAI (Java
 * Advanced Imaging)</a> to perform image manipulation operations on
 * existing images.  The operations are represented as ImageOperation
 * DataType objects.  The operations are arranged to conform to the
 * Chaining Model of JAI.  Check out the <a
 * href="http://java.sun.com/products/java-media/jai/forDevelopers/jai1_0_1guide-unc/">
 * JAI Programming Guide</a>.
 *
 * @see org.apache.tools.ant.types.optional.image.ImageOperation
 * @see org.apache.tools.ant.types.DataType
 */
public class Image extends MatchingTask {
    // CheckStyle:VisibilityModifier OFF - bc
    protected Vector instructions = new Vector();
    protected boolean overwrite = false;
    protected Vector filesets = new Vector();
    protected File srcDir = null;
    protected File destDir = null;

    // CheckStyle:MemberNameCheck OFF - bc

    //cannot remove underscores due to protected visibility >:(
    protected String str_encoding = "JPEG";
    protected boolean garbage_collect = false;

    private boolean failonerror = true;

    // CheckStyle:MemberNameCheck ON

    // CheckStyle:VisibilityModifier ON

    /**
     * Add a set of files to be deleted.
     * @param set the FileSet to add.
     */
    public void addFileset(FileSet set) {
        filesets.addElement(set);
    }

    /**
     * Set whether to fail on error.
     * If false, note errors to the output but keep going.
     * @param failonerror true or false.
     */
    public void setFailOnError(boolean failonerror) {
        this.failonerror = failonerror;
    }

    /**
     * Set the source dir to find the image files.
     * @param srcDir the directory in which the image files reside.
     */
    public void setSrcdir(File srcDir) {
        this.srcDir = srcDir;
    }

    /**
     * Set the image encoding type.  <a
     * href="http://java.sun.com/products/java-media/jai/forDevelopers/jai1_0_1guide-unc/Encode.doc.html#56610">
     * See this table in the JAI Programming Guide</a>.
     * @param encoding the String image encoding.
     */
    public void setEncoding(String encoding) {
        str_encoding = encoding;
    }

    /**
     * Set whether to overwrite a file if there is a naming conflict.
     * @param overwrite whether to overwrite.
     */
    public void setOverwrite(boolean overwrite) {
        this.overwrite = overwrite;
    }

    /**
     * Set whether to invoke Garbage Collection after each image processed.
     * Defaults to false.
     * @param gc whether to invoke the garbage collector.
     */
    public void setGc(boolean gc) {
        garbage_collect = gc;
    }

    /**
     * Set the destination directory for manipulated images.
     * @param destDir The destination directory.
     */
    public void setDestDir(File destDir) {
        this.destDir = destDir;
    }

    /**
     * Add an ImageOperation to chain.
     * @param instr The ImageOperation to append to the chain.
     */
    public void addImageOperation(ImageOperation instr) {
        instructions.add(instr);
    }

    /**
     * Add a Rotate ImageOperation to the chain.
     * @param instr The Rotate operation to add to the chain.
     * @see org.apache.tools.ant.types.optional.image.Rotate
     */
    public void addRotate(Rotate instr) {
        instructions.add(instr);
    }

    /**
     * Add a Scale ImageOperation to the chain.
     * @param instr The Scale operation to add to the chain.
     * @see org.apache.tools.ant.types.optional.image.Scale
     */
    public void addScale(Scale instr) {
        instructions.add(instr);
    }

    /**
     * Add a Draw ImageOperation to the chain.  DrawOperation
     * DataType objects can be nested inside the Draw object.
     * @param instr The Draw operation to add to the chain.
     * @see org.apache.tools.ant.types.optional.image.Draw
     * @see org.apache.tools.ant.types.optional.image.DrawOperation
     */
    public void addDraw(Draw instr) {
        instructions.add(instr);
    }

    /**
    * Add an ImageOperation to chain.
    * @param instr The ImageOperation to append to the chain.
    * @since Ant 1.7
    */
    public void add(ImageOperation instr) {
        addImageOperation(instr);
    }

    /**
     * Executes all the chained ImageOperations on the file
     * specified.
     * @param file The file to be processed.
     */
    public void processFile(File file) {
        try {
            log("Processing File: " + file.getAbsolutePath());
            FileSeekableStream input = new FileSeekableStream(file);
            PlanarImage image = JAI.create("stream", input);
            for (int i = 0; i < instructions.size(); i++) {
                Object instr = instructions.elementAt(i);
                if (instr instanceof TransformOperation) {
                    image = ((TransformOperation) instr)
                        .executeTransformOperation(image);
                } else {
                    log("Not a TransformOperation: " + instr);
                }
            }
            input.close();

            if (str_encoding.toLowerCase().equals("jpg")) {
                str_encoding = "JPEG";
            } else if (str_encoding.toLowerCase().equals("tif")) {
                str_encoding = "TIFF";
            }
            if (destDir == null) {
                destDir = srcDir;
            }
            File newFile = new File(destDir, file.getName());

            if ((overwrite && newFile.exists()) && (!newFile.equals(file))) {
                newFile.delete();
            }
            FileOutputStream stream = new FileOutputStream(newFile);

            JAI.create("encode", image, stream, str_encoding.toUpperCase(),
                       null);
            stream.flush();
            stream.close();
        } catch (IOException err) {
            if (!failonerror) {
                log("Error processing file:  " + err);
            } else {
                throw new BuildException(err);
            }
        } catch (java.lang.RuntimeException rerr) {
            if (!failonerror) {
                log("Error processing file:  " + rerr);
            } else {
                throw new BuildException(rerr);
            }
        }
    }

    /**
     * Executes the Task.
     * @throws BuildException on error.
     */
    public void execute() throws BuildException {

        validateAttributes();

        try {
            DirectoryScanner ds = null;
            String[] files = null;
            ArrayList filesList = new ArrayList();

            // deal with specified srcDir
            if (srcDir != null) {
                ds = super.getDirectoryScanner(srcDir);

                files = ds.getIncludedFiles();
                for (int i = 0; i < files.length; i++) {
                    filesList.add(new File(srcDir, files[i]));
                }
            }
            // deal with the filesets
            for (int i = 0; i < filesets.size(); i++) {
                FileSet fs = (FileSet) filesets.elementAt(i);
                ds = fs.getDirectoryScanner(getProject());
                files = ds.getIncludedFiles();
                File fromDir = fs.getDir(getProject());
                for (int j = 0; j < files.length; j++) {
                    filesList.add(new File(fromDir, files[j]));
                }
            }
            if (!overwrite) {
                // remove any files that shouldn't be overwritten.
                ArrayList filesToRemove = new ArrayList();
                for (Iterator i = filesList.iterator(); i.hasNext();) {
                    File f = (File) i.next();
                    File newFile = new File(destDir, f.getName());
                    if (newFile.exists()) {
                        filesToRemove.add(f);
                    }
                }
                filesList.removeAll(filesToRemove);
            }
            // iterator through all the files and process them.
            for (Iterator i = filesList.iterator(); i.hasNext();) {
                File file = (File) i.next();

                processFile(file);
                if (garbage_collect) {
                    System.gc();
                }
            }
        } catch (Exception err) {
            err.printStackTrace();
            throw new BuildException(err.getMessage());
        }
    }

    /**
     * Ensure we have a consistent and legal set of attributes, and set
     * any internal flags necessary based on different combinations
     * of attributes.
     * @throws BuildException on error.
     */
    protected void validateAttributes() throws BuildException {
        if (srcDir == null && filesets.size() == 0) {
            throw new BuildException("Specify at least one source"
                                     + "--a srcDir or a fileset.");
        }
        if (srcDir == null && destDir == null) {
            throw new BuildException("Specify the destDir, or the srcDir.");
        }
    }
}