Ant example source code file (LeadPipeInputStream.java)

This example Ant source code file (LeadPipeInputStream.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

io, ioexception, ioexception, leadpipeinputstream, leadpipeinputstream, pipedinputstream, pipedinputstream, projectcomponent, projectcomponent

The LeadPipeInputStream.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.util;

import java.io.IOException;
import java.io.PipedInputStream;
import java.io.PipedOutputStream;

import org.apache.tools.ant.ProjectComponent;
import org.apache.tools.ant.Task;
import org.apache.tools.ant.Project;

/**
 * Special <code>PipedInputStream that will not die
 * when the writing <code>Thread is no longer alive.
 * @since Ant 1.6.2
 */
public class LeadPipeInputStream extends PipedInputStream {
    private ProjectComponent managingPc;

    /**
     * Construct a new <code>LeadPipeInputStream.
     */
    public LeadPipeInputStream() {
        super();
    }

    /**
     * Construct a new <code>LeadPipeInputStream
     * with the specified buffer size.
     * @param size   the size of the circular buffer.
     */
    public LeadPipeInputStream(int size) {
        super();
        setBufferSize(size);
    }

    /**
     * Construct a new <code>LeadPipeInputStream to pull
     * from the specified <code>PipedOutputStream.
     * @param src   the <code>PipedOutputStream source.
     * @throws IOException if unable to construct the stream.
     */
    public LeadPipeInputStream(PipedOutputStream src) throws IOException {
        super(src);
    }

    /**
     * Construct a new <code>LeadPipeInputStream to pull
     * from the specified <code>PipedOutputStream, using a
     * circular buffer of the specified size.
     * @param src    the <code>PipedOutputStream source.
     * @param size   the size of the circular buffer.
     * @throws IOException if there is an error.
     */
    public LeadPipeInputStream(PipedOutputStream src, int size) throws IOException {
        super(src);
        setBufferSize(size);
    }

    //inherit doc
    /**
     * Read a byte from the stream.
     * @return the byte (0 to 255) or -1 if there are no more.
     * @throws IOException if there is an error.
     */
    public synchronized int read() throws IOException {
        int result = -1;
        try {
            result = super.read();
        } catch (IOException eyeOhEx) {
            if ("write end dead".equalsIgnoreCase(eyeOhEx.getMessage())) {
                if (super.in > 0 && super.out < super.buffer.length
                    && super.out > super.in) {
                    result = super.buffer[super.out++] & 0xFF;
                }
            } else {
                log("error at LeadPipeInputStream.read():  "
                    + eyeOhEx.getMessage(), Project.MSG_INFO);
            }
        }
        return result;
    }

    /**
     * Set the size of the buffer.
     * @param size   the new buffer size.  Ignored if <= current size.
     */
    public synchronized void setBufferSize(int size) {
        if (size > buffer.length) {
            byte[] newBuffer = new byte[size];
            if (in >= 0) {
                if (in > out) {
                    System.arraycopy(buffer, out, newBuffer, out, in - out);
                } else {
                    int outlen = buffer.length - out;
                    System.arraycopy(buffer, out, newBuffer, 0, outlen);
                    System.arraycopy(buffer, 0, newBuffer, outlen, in);
                    in += outlen;
                    out = 0;
                }
            }
            buffer = newBuffer;
        }
    }

    /**
     * Set a managing <code>Task for
     * this <code>LeadPipeInputStream.
     * @param task   the managing <code>Task.
     */
    public void setManagingTask(Task task) {
        setManagingComponent(task);
    }

    /**
     * Set a managing <code>ProjectComponent for
     * this <code>LeadPipeInputStream.
     * @param pc   the managing <code>ProjectComponent.
     */
    public void setManagingComponent(ProjectComponent pc) {
        this.managingPc = pc;
    }

    /**
     * Log a message with the specified logging level.
     * @param message    the <code>String message.
     * @param loglevel   the <code>int logging level.
     */
    public void log(String message, int loglevel) {
        if (managingPc != null) {
            managingPc.log(message, loglevel);
        } else {
            if (loglevel > Project.MSG_WARN) {
                System.out.println(message);
            } else {
                System.err.println(message);
            }
        }
    }
}