Java thread Basics

Why multithreading?

 

. Model simplification. For example, some programs run by multiple relatively independent tasks:

The appearance of the graphic interface, the obstruction of Input and Output

. Better use of multi-core CPU

. Asynchronous behavior needs

 

Java multithreading features:

Main itself is a thread.

. Threads are concurrent and unordered.

The threads are executed sequentially.

. Share Data

 

Java multithreading risks:

. Security Risk: because the operation sequence of the thread is uncertain, some programs that can run in a single thread may encounter unexpected results under multiple threads.

. Performance risks: Server throughput, responsiveness, and resource consumption

 

Java multi-thread API:

Java can create threads in two forms: 1. Implement the Runnable interface and 2. inherit the Thread class.

 

Sample Code for inheriting thread Creation

6. 0; I <10; I ++ ){
7. "Main:" + I );
13. 0; I <10; I ++ ){
14. "Thread:" + I );

 

Implement runnable thread creation code

9. 0; I <10; I ++ ){
10. "Main:" + I );
16. 0; I <10; I ++ ){
17. "Thread:" + I );

 

 

Java thread pool technology: Executors obtains the exceuctorservice thread pool code

8. 99 );
9. "T1 ");
11. "T2 ");