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;}@Overridepublic 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 blocke1.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() {@Overridepublic void actionPerformed(ActionEvent e) {// TODO Auto-generated method stubtry{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