java多个进程通信 java 多进程

Java多进程

Java多线程的实现

Java中的多线程由Thread类来实现，主要由两种方法。

• 声明一个类来继承Thread，重写run方法。然后通过子类实例启动一个新的进程。

public class MyThread extends Thread {
    @Override
    public void run() {
        //
    }
}

public static void main(String[] args) {
    Thread t1 = new MyThread();
    Thread t2 = new Thread() {
        @Overide
        public void run() {
            //
        }
    };
    t1.start();
    t2.start();
}

• 声明一个类来实现Runnable接口，实现run方法。创建Thread对象时传递实现类最为参数

public class MyRunnable implements Runnable {
    @Override
    public void run() {
        //
    }
}

public static void main(String[] args) {
    MyRunnable myRunnable = new MyRunnable();
    Thread thread = new Thread(myRunnable);
    thread.start();
}

Java中的进程的状态

A thread state. A thread can be in one of the following states:

• NEW
  A thread that has not yet started is in this state.
• RUNNABLE
  A thread executing in the Java virtual machine is in this state.
• BLOCKED
  A thread that is blocked waiting for a monitor lock is in this state.
• WAITING
  A thread that is waiting indefinitely for another thread to perform a particular action is in this state.
• TIMED_WAITING
  A thread that is waiting for another thread to perform an action for up to a specified waiting time is in this state.
• TERMINATED
  A thread that has exited is in this state.

A thread can be in only one state at a given point in time. These states are virtual machine states which do not reflect any operating system thread states.

线程同步