org.wso2.carbon.integration.common.extensions.utils.InputStreamHandler.java Source code

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Here is the source code for org.wso2.carbon.integration.common.extensions.utils.InputStreamHandler.java

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/*
*Copyright (c) 2005-2010, WSO2 Inc. (http://www.wso2.org) All Rights Reserved.
*
*WSO2 Inc. 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.wso2.carbon.integration.common.extensions.utils;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

/**
 * This class is used to consume the input streams and error streams of the
 * processes created by Runtime.exec() to avoid possible deadlock situations due
 * to unconsumed input streams.
 * An instance of this class will be created for input stream and output stream
 * of each process and it will log those streams to the standard output.
 */
public class InputStreamHandler implements Runnable {
    private String streamType;
    private InputStream inputStream;
    private StringBuilder stringBuilder;
    private static final String STREAM_TYPE_IN = "inputStream";
    private static final String STREAM_TYPE_ERROR = "errorStream";
    private volatile boolean running = true;

    private static final Log log = LogFactory.getLog(InputStreamHandler.class);

    public InputStreamHandler(String name, InputStream is) {
        this.streamType = name;
        this.inputStream = is;
        this.stringBuilder = new StringBuilder();
    }

    public void start() {
        Thread thread = new Thread(this);
        thread.start();
    }

    public void stop() {
        running = false;
    }

    public void run() {
        InputStreamReader inputStreamReader = null;
        try {

            inputStreamReader = new InputStreamReader(inputStream, "ISO-8859-1");
            BufferedReader bufferedReader = new BufferedReader(inputStreamReader);

            while (running) {
                if (bufferedReader.ready()) {
                    String s = bufferedReader.readLine();
                    stringBuilder.setLength(0);
                    if (s == null) {
                        break;
                    }
                    if (STREAM_TYPE_IN.equals(streamType)) {
                        stringBuilder.append(s).append("\n");
                        log.info(s);
                    } else if (STREAM_TYPE_ERROR.equals(streamType)) {
                        stringBuilder.append(s).append("\n");
                        log.error(s);
                    }
                }
            }
        } catch (Exception ex) {
            log.error("Problem reading the [" + streamType + "] due to: " + ex.getMessage(), ex);

        } finally {
            if (inputStreamReader != null) {
                try {
                    inputStream.close();
                } catch (IOException e) {
                    log.error("Error occured while closing the stream: " + e.getMessage(), e);
                }
            }

        }
    }

    public String getOutput() {
        return stringBuilder.toString();
    }

}