java 多執行緒基礎之一:多執行緒建立，執行，狀態管理
阿新 • • 發佈：2019-02-09
import java.lang.Thread.State;
public class Calculator implements Runnable {
private int number;
public Calculator(int number) {
this.number=number;
}
public void run() {
for (int i=1; i<=10; i++){
System.out.printf("%s: %d * %d = %d\n",Thread.currentThread().getName(),number,i,i*number);
}
}
public static void main(String[] args) {
System.out.printf("Minimum Priority: %s\n",Thread.MIN_PRIORITY);
System.out.printf("Normal Priority: %s\n",Thread.NORM_PRIORITY);
System.out.printf("Maximun Priority: %s\n",Thread.MAX_PRIORITY);
Thread threads[];
Thread.State status[];
//發起10個執行緒，5個最高優先順序，5個最低優先順序,並設定執行緒的名字
threads=new Thread[10];
status=new Thread.State[10];
for (int i=0; i<10; i++){
threads[i]=new Thread(new Calculator(i));
if ((i%2)==0){
threads[i].setPriority(Thread.MAX_PRIORITY);
} else {
threads[i].setPriority(Thread.MIN_PRIORITY);
}
threads[i].setName("Thread "+i+"執行緒");
}
// Wait for the finalization of the threads. Meanwhile,
// write the status of those threads in a file
try {
for (int i=0; i<10; i++){
System.out.println("Main : Status of Thread "+i+" : "+threads[i].getState());
status[i]=threads[i].getState();
}
for (int i=0; i<10; i++){
threads[i].start();
}
boolean finish=false;
while (!finish) {
for (int i=0; i<10; i++){
if (threads[i].getState()!=status[i]) {
writeThreadInfo(threads[i],status[i]);
status[i]=threads[i].getState();
}
}
finish=true;
for (int i=0; i<10; i++){
finish=finish &&(threads[i].getState()==State.TERMINATED);
}
}
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* 列印執行緒狀態
* @param thread : Thread
* @param state : Old state of the thread
*/
private static void writeThreadInfo(Thread thread, State state) {
System.out.printf("Main : Id %d - %s\n",thread.getId(),thread.getName());
System.out.printf("Main : Priority: %d\n",thread.getPriority());
System.out.printf("Main : Old State: %s\n",state);
System.out.printf("Main : New State: %s\n",thread.getState());
System.out.println("Main : ************************************\n");
}
}