Tools/Java/Source/Cpptasks/net/sf/antcontrib/cpptasks/compiler/CaptureStreamHandler.java

/*
 * 
 * Copyright 2001-2004 The Ant-Contrib project
 *
 *  Licensed 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 net.sf.antcontrib.cpptasks.compiler;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.util.Vector;

import org.apache.tools.ant.taskdefs.Execute;
import org.apache.tools.ant.taskdefs.ExecuteStreamHandler;
/**
 * Implements ExecuteStreamHandler to capture the output of a Execute to an
 * array of strings
 * 
 * @author Curt Arnold
 */
public class CaptureStreamHandler implements ExecuteStreamHandler {
    /**
     * Runs an executable and captures the output in a String array
     * 
     * @param cmdline
     *            command line arguments
     * @return output of process
     */
    public static String[] run(String[] cmdline) {
        CaptureStreamHandler handler = new CaptureStreamHandler();
        Execute exec = new Execute(handler);
        exec.setCommandline(cmdline);
        try {
            int status = exec.execute();
        } catch (IOException ex) {
        }
        return handler.getOutput();
    }
    private InputStream errorStream;
    private InputStream fromProcess;
    public CaptureStreamHandler() {
    }
    public String[] getOutput() {
        String[] output;
        if (fromProcess != null) {
            Vector lines = new Vector(10);
            try {
                BufferedReader reader = new BufferedReader(
                        new InputStreamReader(errorStream));
                for (int i = 0; i < 2; i++) {
                    for (int j = 0; j < 100; j++) {
                        String line = reader.readLine();
                        if (line == null) {
                            reader = new BufferedReader(new InputStreamReader(
                                    fromProcess));
                            break;
                        }
                        lines.addElement(line);
                    }
                }
            } catch (IOException ex) {
            }
            output = new String[lines.size()];
            lines.copyInto(output);
            return output;
        }
        output = new String[0];
        return output;
    }
    /**
     * Install a handler for the error stream of the subprocess.
     * 
     * @param is
     *            input stream to read from the error stream from the
     *            subprocess
     */
    public void setProcessErrorStream(InputStream is) throws IOException {
        errorStream = is;
    }
    /**
     * Install a handler for the input stream of the subprocess.
     * 
     * @param os
     *            output stream to write to the standard input stream of the
     *            subprocess
     */
    public void setProcessInputStream(OutputStream os) throws IOException {
        os.close();
    }
    /**
     * Install a handler for the output stream of the subprocess.
     * 
     * @param is
     *            input stream to read from the error stream from the
     *            subprocess
     */
    public void setProcessOutputStream(InputStream is) throws IOException {
        fromProcess = is;
    }
    /**
     * Start handling of the streams.
     */
    public void start() throws IOException {
    }
    /**
     * Stop handling of the streams - will not be restarted.
     */
    public void stop() {
    }
}