Thread-based conceptual stuff

1. What is a thread
* Thread is a path for program execution, one process can contain multiple threads
* Multi-threaded concurrent execution can improve the efficiency of the program, can complete a number of tasks at the same time
* 2. Multi-Threaded application scenarios
* Starscream sharing screen to multiple computers simultaneously
* Thunder open multiple threads to download together
* QQ at the same time and many people together video
* The server processes multiple client requests at the same time

# # #24.02_ Multithreading (differences between multithreading parallelism and concurrency) (learn)
* Parallel is two tasks at the same time, is a mission to carry out while the B task is also in progress. (Multi-core CPU required)
* Concurrency means that two tasks are requested to run, and the processor can only be subject to a task, the two tasks are scheduled to take turns, because of the short time interval, makes the sense that both tasks are running.
* For example, I chat with two netizens, left hand operation a computer with a chat, while the right hand with another computer with B chat, this is called parallel.
* If you use a computer I send a message first, and then immediately send a message to B, and then chat with a, and then chat with B. This is called concurrency .

There are two ways to implement threads:

1. Inherit thread
* Define class Inheritance Thread
* Override the Run method
* Write what the new thread is going to do in the Run method
* Create Thread Object
* Start a new thread and the Run method is automatically executed internally
*

public class Demo2_thread {

/**
* @param args
*/
public static void Main (string[] args) {
MyThread MT = new MyThread ();//4, creating an object of the custom class
Mt.start ();//5, opening thread

for (int i = 0; i <; i++) {
System.out.println ("BB");
}
}

}
Class MyThread extends Thread {//1, defining classes inheriting thread
public void Run () {//2, overriding the Run method
for (int i = 0; i < i++) {//3, code to be executed, written in the Run method
System.out.println ("aaaaaaaaaaaaaaaaaaaaaaaaaaaa");
}
}
}

2. Implement Runnable
* Define class implementation Runnable interface
* Implement the Run method
* Write what the new thread is going to do in the Run method
* Create a custom Runnable subclass object
* Create thread object, incoming runnable
* Call Start () to open a new thread, the internal will automatically call Runnable's Run () method

public class Demo3_runnable {
/**
* @param args
*/
public static void Main (string[] args) {
Myrunnable Mr = New Myrunnable ();//4, creating a custom class object
Runnable target = new myrunnable ();
Thread t = new thread (MR);//5, which is passed as an argument to the constructor of thread
T.start ();//6, opening thread

for (int i = 0; i <; i++) {
System.out.println ("BB");
}
}
}

Class Myrunnable implements Runnable {//1, custom class implementation Runnable interface
@Override
public void Run () {//2, overriding the Run method
for (int i = 0; i < i++) {//3, code to be executed, written in the Run method
System.out.println ("aaaaaaaaaaaaaaaaaaaaaaaaaaaa");
}
}

}

The way to implement two threads with anonymous inner classes

Inherit the thread class

The new Thread () {//1,new class () {} Inherits this class
public void Run () {//2, overriding the Run method
for (int i = 0; i < i++) {//3, code to be executed, written in the Run method
System.out.println ("aaaaaaaaaaaaaaaaaaaaaaaaaaaa");
}
}
}.start ();
* Implement Runnable interface

The new Thread (new Runnable () {//1,new interface () {} Implements this interface
public void Run () {//2, overriding the Run method
for (int i = 0; i < i++) {//3, code to be executed, written in the Run method
System.out.println ("BB");
}
}
}). Start ();

Multithreading (get first name and set name)

1. Get the name
* Get the name of the thread object through the GetName () method
* 2. Set the name
* A String type name can be passed through the constructor function
*
New Thread ("xxx") {
public void Run () {
for (int i = 0; i <; i++) {
System.out.println (This.getname () + ".... aaaaaaaaaaaaaaaaaaaaaaa");
}
}
}.start ();

New Thread ("yyy") {
public void Run () {
for (int i = 0; i <; i++) {
System.out.println (This.getname () + ".... bb");
}
}
}.start ();
* The name of the thread object can be set by the SetName (String) method
*
thread T1 = new Thread () {
public void Run () {
for (int i = 0; i <; i++) {
System.out.println (This.getname () + ".... aaaaaaaaaaaaaaaaaaaaaaa");
}
}
};

Thread t2 = new Thread () {
public void Run () {
for (int i = 0; i <; i++) {
System.out.println (This.getname () + ".... bb");
}
}
};
T1.setname ("Sister Furong");
T2.setname ("Sister Feng");

T1.start ();
T2.start ();

Gets the current thread with thread.current.

Thread.CurrentThread (), the main thread can also get
*
New Thread (New Runnable () {
public void Run () {
for (int i = 0; i <; i++) {
System.out.println (Thread.CurrentThread (). GetName () + "... aaaaaaaaaaaaaaaaaaaaa");
}
}
}). Start ();

New Thread (New Runnable () {
public void Run () {
for (int i = 0; i <; i++) {
System.out.println (Thread.CurrentThread (). GetName () + "... bb");
}
}
}). Start ();
Thread.CurrentThread (). SetName ("I am the main thread");//Get a reference to the main function thread and change the name
System.out.println (Thread.CurrentThread (). GetName ());

Use of the thread join method

The current thread pauses, waits for the specified thread to finish executing, and then continues

Final thread T1 = new Thread () {
public void Run () {
for (int i = 0; i < i++) {
System.out.println (This.getname () + "... aaa");
}
}
};
Thread t2 = new Thread () {
public void Run () {
for (int i = 0; i < i++) {
if (i = = 2) {
try {
T1.join ();
} catch (Interruptedexception e) {
TODO auto-generated Catch block
E.printstacktrace ();
}
}
System.out.println (This.getname () + ".... BBB");
}
}

};
T1.start ();
T2.start ();
}
}

Multi-threaded (sets the priority of the thread)
* SetPriority () Sets the priority of the thread

Thread-based conceptual stuff