java模拟dos窗口

2019独角兽企业重金招聘Python工程师标准>>>

原来这么简单：

package runtimeTest;

import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Scanner;

public class ProcTest {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		Process process = null;
		try {
			process = Runtime.getRuntime().exec("cmd");
		} catch (IOException e) {
			e.printStackTrace();
		}
		new Thread(new ProcRunnable(process.getInputStream())).start();
		new Thread(new ProcRunnable(process.getErrorStream())).start();

		PrintWriter out = new PrintWriter(process.getOutputStream());
		java.util.Scanner in = new java.util.Scanner(System.in);

		while(in.hasNextLine()){
			out.println(in.nextLine());
			out.flush();

		}
	}
}
class ProcRunnable implements Runnable{

	InputStream inputStream = null;
	String name;
	public ProcRunnable(InputStream inputStream){
		this.inputStream = inputStream;
	}
	@Override
	public void run() {
		Scanner scanner = new Scanner(inputStream);
		while(scanner.hasNextLine()){
			System.out.println(scanner.nextLine());
		}
		try {
			inputStream.close();
		} catch (IOException e) {
			e.printStackTrace();
		}
		scanner.close();
	}
}

这种方法最直接，但是没有下一行时，scanner.hasNextLine()会阻塞在那边，直到下一个换行符。
所以这样感觉和dos窗口有少许区别：dos窗口有一个如“c:\Users\macondo>_”这样的东西提示你输入下一个命令；而以上程序效果是你输入命令后那个提示才出来。原因是那个提示后面没有换行符，等到有换行符时才会被输出。

下面是一种解决方法：用timer定时检查inputstream，有东西就把它输出来：

package cmd;

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;

public class cmd {
	public static void main(String...args) {
		Process process = null;
		PrintWriter writer = null;
		
		final byte[] b = new byte[1024];
		try {
			process = Runtime.getRuntime().exec("cmd");
			writer = new PrintWriter(process.getOutputStream());
			
		} catch (IOException e1) {
			// TODO Auto-generated catch block
			e1.printStackTrace();
		}

		final InputStream inputStream = process.getInputStream();
		final InputStream err = process.getErrorStream();
		java.util.Scanner scanner = new java.util.Scanner(System.in);
		javax.swing.Timer timer = new javax.swing.Timer(500,new ActionListener() {
			
			@Override
			public void actionPerformed(ActionEvent e) {
				// TODO Auto-generated method stub
				try{
					while(inputStream.available()>0){
						int c = inputStream.read(b,0,b.length);
						System.out.print(new String(b,0,c));
					}
				}catch (Exception ee) {
					// TODO: handle exception
				}
				try{
					while(err.available()>0){
						int c = err.read(b,0,b.length);
						System.out.print(new String(b,0,c));
					}
				}catch (Exception ee) {
					// TODO: handle exception
				}
			}
		});
		timer.start();
		while(scanner.hasNextLine()){			
			writer.println(scanner.nextLine());
			writer.flush();
		}
	}
}

以上两种方法都有一个和dos不同的地方，因为在同一个console里面输入，你输入一个命令，outputstream又会把那个命令重复输出一遍。这个好解决，不用让它输出到console,做个jframe，从jtextfield里输入，输出到jtextarea就行了

另外，按下tab建没有自动提示功能，要做到这个可能有难度

转载于:https://my.oschina.net/soitravel/blog/35126