maintaskthread.java

基于图形化的多线程下载器

import java.net.*;
import java.util.*;
import java.io.*;

/*
 * main task thread, start many subTaskThread according to the TaskInfo object
 * give the dstFile, url, and portionInfo to each subTaskThread and start;
 */
public class MainTaskThread extends Thread {
	private boolean debug = true;

	private HashSet<SubTaskThread> subTaskThreadList = null;
	private TaskInfo taskInfo = null;
	private boolean run = true;
	private boolean pause = false;

	public MainTaskThread(TaskInfo taskInfo) {
		this.taskInfo = taskInfo;
		subTaskThreadList = new HashSet<SubTaskThread>();
	}

	public void run() {
		if (taskInfo.finished())
			return;
		allocateSubTaskThread();
		while (run) {
			checkPause();
			if (taskInfo.finished() || taskInfo.getState()==TaskInfo.TASK_STATE_STOP) {
				setRun(false);
			}
		}
		if (debug)
			System.out
					.println("mainTaskThread " + this.getName() + " is died!");
	}

	private void allocateSubTaskThread() {

		if (debug)
			System.out.println("mainTaskThread " + this.getName() + " start!");
		Iterator<TaskPortionInfo> it = taskInfo.getPortionList().iterator();
		while (it.hasNext()) {
			TaskPortionInfo tpi = it.next();
			if (!tpi.finished()) {
				SubTaskThread stt = new SubTaskThread(tpi, taskInfo.getUrl(),
						taskInfo.getDstFile());
				subTaskThreadList.add(stt);
				stt.start();
			}
		}
	}

	private void checkPause() {
		synchronized (this) {
			while (pause) {
				if (debug)
					System.out.println("mainTaskThread " + this.getName()
							+ " pause!");
				try {
					this.wait();
				} catch (InterruptedException e) {
					e.printStackTrace();
				}
			}
		} // synchronized
	}

	public void setRun(boolean run) {
		Iterator it = subTaskThreadList.iterator();
		while(it.hasNext() && !subTaskThreadList.isEmpty()) {
			((SubTaskThread)it.next()).setRun(false);
		}
		this.run = run;
	}

	public void setPause(boolean p) {
		pause = p;

		// if pause be set false, pause all subthread and this thread
		if (pause == true) {
			Iterator<SubTaskThread> it = subTaskThreadList.iterator();
			while (it.hasNext() && !subTaskThreadList.isEmpty()) {
				SubTaskThread stt = (SubTaskThread) it.next();
				if (!stt.isAlive() || stt == null)
					continue;
				stt.setPause(true);
			}
		}
		// if pause be set true, active subthread
		// NOTE:this thread itself need be actived in another thread
		if (pause == false) {
			// unlock all SubTaskThread
			Iterator<SubTaskThread> it = subTaskThreadList.iterator();
			while (it.hasNext() && !subTaskThreadList.isEmpty()) {
				SubTaskThread stt = (SubTaskThread) it.next();
				if (!stt.isAlive() || stt == null)
					continue;
				synchronized (stt) {
					stt.setPause(false);
					stt.notify();
				}
			}
		}
	}

	public TaskInfo getTaskInfo() {
		return taskInfo;
	}

	public void setTaskInfo(TaskInfo taskInfo) {
		this.taskInfo = taskInfo;
	}
}