Java learning notes thread (1), java learning notes thread

Java learning notes thread (1), java learning notes thread
Thread (1) I. Thread definition in composition:

1. Create tasks and threads:

1 TaskThread task = new TaskThread (); // create task 2 Thread taskThread = new Thread (task); // create the corresponding execution Thread Based on the task

2. Implement the Runnable interface for tasks

Override run () method

1 class TaskThread implements Runnable {2... 3 public void run () {4 // execution body, telling the system how to execute thread 5} 6} 7

3. Within the class of the execution thread, the start () method is called to execute the thread.

1 threadtask. start () // main program startup thread

Ii. Thread class

1. Method:

1 Thread () // create an empty Thread 2 Thread (task: Runnable) // create a specified task Thread 3 start (): void // start the Thread run () jvm executes 4 isAlive (): boolean // test whether the current thread is executing 5 join (): void // wait until the thread ends 6 setPriority (p: int ): void // set thread priority, 7 sleep (mills: long): void // thread sleep mills millisecond 8 yield (): void // pause the current thread and allow other threads to execute 9 interrupt (): void // interrupt the thread

2. sleep ()

Sleep () may throw a required check exception for InterruptException, and force a try/catch check exception in java.

3. thread priority

The int constants defined in Thread correspond to different priorities:

MIN_PRIORITY indicates 1;

NORM_PRIORITY indicates 5;

MAX_PRIORITY stands for 10;

Thread. NORM_PRIORITY is the main Thread priority.

The JVM always executes threads with a higher priority and then executes low ones. When the thread priority is the same, put the thread into the loop queue for cyclic scheduling.

Iii. Thread Pool

WeCreate a thread for a taskIs usedThreadClass, and we wantMultiple tasksWhen creating a thread, we need to useThread Pool

Executor InterfaceExecute tasks in the thread pool

ExecutorService is a sub-interface of Executor.

ExecutorsClass,Static MethodNewFixedThreadPool (int threadNum)Create Executor object // create a fixed number of threads in the thread pool

1 import java. util. concurrent. executorService; 2 import static java. util. concurrent. executors. newFixedThreadPool; 3 public class ExecutorDemo {4 public static void main (String [] args) {5 ExecutorService excutor = newFixedThreadPool (3); // The static method does not need a new object, call newFixedThreadPool () directly. The maximum number of threads is 3 6 excutor.exe cute (new PrintChar ('A', 100 )); // Add the first thread to the thread pool 7 excutor.exe cute (new PrintChar ('B', 100); 8 excutor.exe cute (new PrintNum (100); 9 excutor. shutdown (); // actuator off 10} 11}