loopedstreams.java

数据库远程同步软件NetBeans项目源文件 项目采用Jdesktop集成组件（JDesktop Integration Components

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package databasesyncdesktopapplication.stream;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PipedInputStream;
import java.io.PipedOutputStream;

/**
 *
 * @author mjw917
 */
public class LoopedStreams {
 private PipedOutputStream pipedOS =
        new PipedOutputStream();
    private boolean keepRunning = true;
    private ByteArrayOutputStream byteArrayOS =
        new ByteArrayOutputStream() {
        public void close() {
            keepRunning = false;
            try {
                super.close();
                pipedOS.close();
            }
            catch(IOException e) {
                // 记录错误或其他处理
                // 为简单计，此处我们直接结束
                System.exit(1);
            }
        }
    };
    private PipedInputStream pipedIS = new PipedInputStream() {
        public void close() {
            keepRunning = false;
            try    {
                super.close();
            }
            catch(IOException e) {
                // 记录错误或其他处理
                // 为简单计，此处我们直接结束
                System.exit(1);
            }
        }
    };
    public LoopedStreams() throws IOException {
        pipedOS.connect(pipedIS);
        startByteArrayReaderThread();
    } // LoopedStreams()
    public InputStream getInputStream() {
        return pipedIS;
    } // getInputStream()
    public OutputStream getOutputStream() {
        return byteArrayOS;
    } // getOutputStream()
    private void startByteArrayReaderThread() {
        new Thread(new Runnable() {
            public void run() {
                while(keepRunning) {
                    // 检查流里面的字节数
                    if(byteArrayOS.size() > 0) {
                        byte[] buffer = null;
                        synchronized(byteArrayOS) {
                            buffer = byteArrayOS.toByteArray();
                            byteArrayOS.reset(); // 清除缓冲区
                        }
                        try {
                            // 把提取到的数据发送给PipedOutputStream
                            pipedOS.write(buffer, 0, buffer.length);
                        }
                        catch(IOException e) {
                            // 记录错误或其他处理
                            // 为简单计，此处我们直接结束
                            System.exit(1);
                        }
                    }
                    else // 没有数据可用，线程进入睡眠状态
                        try {
                            // 每隔1秒查看ByteArrayOutputStream检查新数据
                            Thread.sleep(1000);
                        }
                        catch(InterruptedException e) {}
                    }
             }
        }).start();
    } // startByteArrayReaderThread()
} // LoopedStreams