Java 命令行工具

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Java

SwingWorker 并行并发执行本地命令 cmd

我使用JAVA swing做了一个命令行工具:

使用的核心技术是SwingWorker,运行效果:

核心工具类:

public class ShellSwingWorker extends SwingWorker<Boolean, Character> {
	/***
	 * 执行命令的正常输出（对程序来说是输入）
	 */
	private BufferedReader br_right = null;
	/***
	 * 执行命令的错误输出（对程序来说是输入）
	 */
	private BufferedReader br_error = null;
	/***
	 * 进程封装类
	 */
	private MyProcess myprocess = null;
	private char word = ' ';
	private int tmp = 0;
	private boolean isPrintVerbose = false;
	private StringBuffer stringbuf = new StringBuffer();
	private JTextPane resultTP = null;
	/***
	 * result textarea' document
	 */
	private Document docment;
	/***
	 * charset of result
	 */
	private String encoding;
	/***
	 * logging
	 */
	protected Logger logger = Logger.getLogger(this.getClass());
	/***
	 * 命令前缀
	 */
	
	public ShellSwingWorker(MyProcess myprocess, BufferedReader br) {
		this.br_right = br;
		this.myprocess = myprocess;

	}

	/***
	 * 构造方法.
	 * 
	 * @param process
	 * @param textPane
	 * @param encoding
	 */
	public ShellSwingWorker(Process process, JTextPane textPane,
			String encoding)
	{
		MyProcess proc = null;
		proc=new MyProcess(process);
		construct(proc,textPane,encoding);
	}
	/***
	 * 构造方法.
	 * 
	 * @param myprocess
	 * @param textPane
	 * @param encoding
	 */
	public ShellSwingWorker(MyProcess myprocess, JTextPane textPane,
			String encoding) {
		construct(myprocess, textPane, encoding);

	}

	private void construct(MyProcess myprocess, JTextPane textPane,
			String encoding){
		this.myprocess = myprocess;
		if (ValueWidget.isNullOrEmpty(encoding)) {
			encoding = SystemHWUtil.CURR_ENCODING;
		}
		this.encoding = encoding;
		try {
			br_right = new BufferedReader(new InputStreamReader(
					myprocess.getInputStream(), this.encoding), 4096);
		} catch (UnsupportedEncodingException e) {
			e.printStackTrace();
		}
		try {
			br_error = new BufferedReader(new InputStreamReader(
					myprocess.getErrorStream(), this.encoding), 4096);
		} catch (UnsupportedEncodingException e) {
			e.printStackTrace();
		}
		this.resultTP = textPane;
		docment = this.resultTP.getDocument();
	}
	@Override
	protected Boolean doInBackground() throws Exception {
		while ((tmp = br_right.read()) != -1) {
			word = (char) tmp;
			publish(word);
		}
		while ((tmp = br_error.read()) != -1) {
			word = (char) tmp;
			publish(word);
		}
		if (isPrintVerbose)// 是否打印详细信息
		{
			System.out.println("doInBackground() over");
		}
		return true;
	}

	@Override
	protected void process(List<Character> chunks) {
		for (char temp : chunks) {
			{
				// System.out.print(temp);
				// this.resultTP.setText(this.stringbuf.toString());//效率低
				int leng2 = this.stringbuf.length();
				try {
					// 追加
					docment.insertString(leng2, String.valueOf(temp), null);
				} catch (BadLocationException e) {
					GUIUtil23.warningDialog(e.getMessage());
					e.printStackTrace();
				}
				this.stringbuf.append(temp);
			}
		}
	}

	public StringBuffer getStringbuf() {
		return stringbuf;
	}

	/***
	 * main thread can't execute next command(below waitFor()) until done() is
	 * executed;if done() hasn't be executed,this.myprocess.waitFor() will wait
	 */
	@Override
	protected void done() {
		if (isPrintVerbose) {
			System.out.println("done() is executed");
		}
		if (!ValueWidget.isNullOrEmpty(br_right)) {
			try {
				br_right.close();
				br_error.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
		String logMesg=this.getClass().getSimpleName()+".done() is executed successfully.";
		logger.debug(logMesg);
		System.out.println(logMesg);
		this.myprocess.stopLoop();
	}

	public MyProcess getProcess() {
		return myprocess;
	}

项目采用maven构建,结构如下:

笔记:

遇到的问题

（1）卡了？

为什么呢？确实是使用的线程啊？

原因：

@Override

protectedvoid process(List<Character> chunks)

{

for (char temp : chunks)

{

// System.out.print(temp);

this.stringbuf.append(temp);

this.resultTP.setText(this.stringbuf.toString());

}

标红的代码影响性能

解决方法：

swingwork中done()方法还没有完全执行完毕，就执行proc.waitFor()后面的语句

使用swingwork 可以在界面上异步的看到执行结果，而不是等待执行完之后才一次性打印出来，影响用户体验。这就是swingwork存在的目的。

解决方法：

对Process进行封装，看下面标黄的代码，若loop为true则会死循环，一直等待。

package com.common.util;

import java.io.InputStream;

import java.io.OutputStream;

publicclass MyProcess extends Process

{

private Process proc;

privatebooleanloop=true;

public Process getProc()

{

returnproc;

}

publicboolean isLoop()

{

returnloop;

}

/***

* should be invoked in end

public int waitFor()

throws InterruptedException{

int waitFor_exitcode= proc.waitFor();

/*must wait until ShellSwingWorker.done() is executed. */

while (loop)

{

Thread.sleep(100);

}

return waitFor_exitcode;

}

publicvoid stopLoop(){

loop=false;

}

public OutputStream getOutputStream(){

returnproc.getOutputStream();

}

public InputStream getInputStream(){

returnproc.getInputStream();

}

public InputStream getErrorStream(){

returnproc.getErrorStream();

}

public int exitValue(){

returnproc.exitValue();

}

public MyProcess(Process proc)

{

super();

this.proc = proc;

}

@Override

publicvoid destroy()

{

this.proc.destroy();

}

那么时候终止循环呢？

在swingwork的done（）方法中：

@Override

protectedvoid done() {

if (isPrintVerbose) {

System.out.println("done() is executed");

}

if (!ValueWidget.isNullOrEmpty(br_right)) {

try {

br_right.close();

br_error.close();

} catch (IOException e) {

e.printStackTrace();

}

this.myprocess.stopLoop();

}

下面是有问题的：

Process p3=pb.start();

ShellSwingWorker worker = new ShellSwingWorker(p3, resultTP,

encoding);

worker.execute();

Process proc = worker.getProcess();

p3.waitFor();

System.out.println("proc.waitFor() is executed.");

// result2 = worker.getStringbuf().toString();

int exitCode2 = proc.exitValue();

执行结果：

下面的事正确的：

ShellSwingWorker worker = new ShellSwingWorker(pb.start(), resultTP,

encoding);

worker.execute();

Process proc = worker.getProcess();

proc.waitFor();

System.out.println("proc.waitFor() is executed.");

// result2 = worker.getStringbuf().toString();

int exitCode2 = proc.exitValue();

执行结果如下：