Ant example source code file (Echo.java)

This example Ant source code file (Echo.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

bufferedwriter, bufferedwriter, buildexception, buildexception, echo, echolevel, file, fileoutputstream, io, ioexception, outputstreamwriter, string, string, task, writer

The Echo.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;

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.io.Writer;
import java.io.BufferedWriter;
import java.io.OutputStreamWriter;
import java.io.FileOutputStream;

import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.Project;
import org.apache.tools.ant.Task;
import org.apache.tools.ant.util.FileUtils;
import org.apache.tools.ant.types.LogLevel;

/**
 * Writes a message to the Ant logging facilities.
 *
 * @since Ant 1.1
 *
 * @ant.task category="utility"
 */
public class Echo extends Task {
    // CheckStyle:VisibilityModifier OFF - bc
    protected String message = "";
    protected File file = null;
    protected boolean append = false;
    /** encoding; set to null or empty means 'default' */
    private String encoding = "";

    // by default, messages are always displayed
    protected int logLevel = Project.MSG_WARN;
    // CheckStyle:VisibilityModifier ON

    /**
     * Does the work.
     *
     * @exception BuildException if something goes wrong with the build
     */
    public void execute() throws BuildException {
        if (file == null) {
            log(message, logLevel);
        } else {
            Writer out = null;
            try {
                String filename = file.getAbsolutePath();
                if (encoding == null || encoding.length() == 0) {
                    out = new FileWriter(filename, append);
                } else {
                    out = new BufferedWriter(
                            new OutputStreamWriter(
                                new FileOutputStream(filename, append), encoding));
                }
                out.write(message, 0, message.length());
            } catch (IOException ioe) {
                throw new BuildException(ioe, getLocation());
            } finally {
                FileUtils.close(out);
            }
        }
    }

    /**
     * Message to write.
     *
     * @param msg Sets the value for the message variable.
     */
    public void setMessage(String msg) {
        this.message = msg;
    }

    /**
     * File to write to.
     * @param file the file to write to, if not set, echo to
     *             standard output
     */
    public void setFile(File file) {
        this.file = file;
    }

    /**
     * If true, append to existing file.
     * @param append if true, append to existing file, default
     *               is false.
     */
    public void setAppend(boolean append) {
        this.append = append;
    }

    /**
     * Set a multiline message.
     * @param msg the CDATA text to append to the output text
     */
    public void addText(String msg) {
        message += getProject().replaceProperties(msg);
    }

    /**
     * Set the logging level. Level should be one of
     * <ul>
     *  <li>error
     *  <li>warning
     *  <li>info
     *  <li>verbose
     *  <li>debug
     * </ul>
     * <p>The default is "warning" to ensure that messages are
     * displayed by default when using the -quiet command line option.</p>
     * @param echoLevel the logging level
     */
    public void setLevel(EchoLevel echoLevel) {
        logLevel = echoLevel.getLevel();
    }

    /**
     * Declare the encoding to use when outputting to a file;
     * Use "" for the platform's default encoding.
     * @param encoding the character encoding to use.
     * @since 1.7
     */
    public void setEncoding(String encoding) {
        this.encoding = encoding;
    }

    /**
     * The enumerated values for the level attribute.
     */
    public static class EchoLevel extends LogLevel {
    }
}