创建多进程

package thread;


import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.InputStreamReader;

//子进程
public class TestFile {

/**
* @param args
* @throws IOException
*/
public static void main(String[] args) throws IOException {

BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
System.out.println("由父进程调用的信息："+br.readLine());
// TODO Auto-generated method stub
File f=new File("D:/demo/testfile.txt");
f.createNewFile();
System.out.println("被调用成功！");
//System.in.read();
}

}


一、通过RunTimepackage thread;

import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.LineNumberReader;
import java.io.OutputStreamWriter;

//给子进程程序传递输入信息
public class TestRunTime2 {

/**
* @param args
* @throws IOException
*/
public static void main(String[] args) throws IOException {
// TODO Auto-generated method stub
System.out.println("主进程调用开始");
Runtime run=Runtime.getRuntime();
Process p=run.exec("java thread.TestFile");

//向子进程输入
BufferedWriter bw=new BufferedWriter(new OutputStreamWriter(p.getOutputStream()));
bw.write("Hello World!");
bw.flush();
bw.close();

//获取子进程信息
BufferedInputStream bi=new BufferedInputStream(p.getInputStream());
BufferedReader br=new BufferedReader(new InputStreamReader(bi));
//或执行下面一行也可以
//BufferedReader br=new BufferedReader(new InputStreamReader(p.getInputStream()));

String s;
while((s=br.readLine())!=null){
System.out.println("子进程输出："+s);
}
System.out.println("主进程调用结束");
br.close();
bi.close();
}

}

二、通过ProcessBuilder
package thread;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.LineNumberReader;
import java.io.OutputStreamWriter;

/**
* ProcessBuilder创建进程
* 与Runtime类似，不同的是一个是start一个是exec来启动子进程
* @author wxg1022
*
*/
public class TestProcessBuilder {

/**
* @param args
* @throws IOException
*/
public static void main(String[] args) throws IOException {
// TODO Auto-generated method stub
ProcessBuilder p=new ProcessBuilder("java","thread.TestFile");
Process process=p.start();

BufferedWriter bw=new BufferedWriter(new OutputStreamWriter(process.getOutputStream()));
bw.write("Hello java");
bw.flush();
bw.close();

BufferedReader br=new BufferedReader(new InputStreamReader(process.getInputStream()));
String s;
while((s=br.readLine())!=null){
System.out.println("输出："+s);
}
}

}