java其他线程获取main线程的状态 java获取线程名

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mob64ca14079fb3 2024-07-03 18:17:51

文章标签 java其他线程获取main线程的状态 System i++ 优先级 文章分类 Java 后端开发

1、线程属性

Thread类包含几个属性，这些属性所表示的信息能帮助我们识别线程、观察其状态、控制其优先级等。这些线程包括如下几种：

ID：该属性表示每个线程的唯一标识；
Name：该属性存储每个线程的名称；
Priority：该属性存储每个Thread对象的优先级。线程优先级分1到10十个级别，1表示最低优先级，10表示最高优先级。并不推荐修改线程的优先级，但是如果确实有这方面的需求，也可以尝试一下。
Status: 该属性存储线程的状态。线程共有六种不同的状态：新建（NEW）、运行（RUNNABLE）、阻塞（BLOCKED）、等待（WAITING）、限时等待（TIMED_WAITING）或者终止（TERMINATED）。线程的状态必定是其中一种。

2、代码实现

本例子展现了使用线程运行乘法口诀，获取和设置线程属性。线程类如下：

package com.xxx.util;

/**
 * Created with IntelliJ IDEA.
 * Date: 15-3-25
 * Time: 上午8:40
 * To change this template use File | Settings | File Templates.
 */
public class ThreadPrioritySet implements Runnable {

    private int num;

    public ThreadPrioritySet(int num){
        this.num = num;
    }

    @Override
    public void run() {
        for(int i=1;i<10;i++){
            System.out.printf("%s：%d*%d=%d\n",Thread.currentThread().getName(),num,i,i*num);
        }
    }
}

main类：

package com.xxx.util;


import java.io.*;
import java.util.Date;


/**
 * Created with IntelliJ IDEA.
 * Date: 15-3-25
 * Time: 上午8:47
 * To change this template use File | Settings | File Templates.
 */
public class ThreadPrioritySetMain {


    public static void main(String[] args){
        long startTime = new Date().getTime();
        System.out.printf("*******************开始时间%d******************************\n",startTime);
        Thread threads[] = new Thread[10];
        Thread.State status[] = new Thread.State[10];
        for(int i=1;i<10;i++){
            threads[i] = new Thread(new ThreadPrioritySet(i));
            if((i%2)==0){
                threads[i].setPriority(Thread.MAX_PRIORITY);
            }else {
                threads[i].setPriority(Thread.MIN_PRIORITY);
            }
            threads[i].setName("Tread "+i);
        }
        PrintWriter printWriter = null;
        File file = null;
        try {
            //System.getProperty("user.dir")是取得当前项目的根目录;
            File filePath = new File(System.getProperty("user.dir")+"\\data\\");
            if(!filePath.exists()){
                filePath.mkdirs();
            }
            file = new File(filePath+"\\threadPrioritySet.txt");
            if(!file.exists()){
                file.createNewFile();
            }
            //可是第二个参数设置追加（true），默认不追加，即覆盖
            FileWriter fileWriter = new FileWriter(file);
            printWriter = new PrintWriter(fileWriter);
            //BufferedWriter 提供缓冲，用以加速
            //printWriter = new PrintWriter(new BufferedWriter(fileWriter));
            for(int i=1;i<10;i++){
                printWriter.println("Main：Status of Thread "+i+"："+threads[i].getState());
                status[i] = threads[i].getState();
            }
            //启动线程
            for(int i=1;i<10;i++){
                threads[i].start();
            }
            boolean finish = false;
            while (!finish){
                for(int i=1;i<10;i++){
                    if(threads[i].getState()!=status[i]){//判断线程状态是否发生变化
                        System.out.println("+++++++++++start+++++++++++++"+i);
                        writeThreadInfo(printWriter,threads[i],status[i]);
                        System.out.println("+++++++++++end+++++++++++++"+i);
                        status[i] = threads[i].getState();
                    }
                }
                finish = true;
                 //判断线程是否TERMINATED，直到线程都运行完成，任何一个线程的状态发生变化，就会将它写入文件中
                for(int i=1;i<10;i++){
                    //赋值运算，获取线程状态，如果不是TERMINATED，finish=false再进行while循环
                    finish = finish&&(threads[i].getState()== Thread.State.TERMINATED);
                }
            }
        } catch (IOException e) {
            e.printStackTrace();  //To change body of catch statement use File | Settings | File Templates.
        }finally {
            if(printWriter!=null){
                printWriter.flush();
                printWriter.close();//需要关闭才能写入
                long endTime = new Date().getTime();
                System.out.printf("*******************结束时间%d******************************\n",new Date().getTime());
                System.out.printf("*******************耗时%d******************************\n", endTime - startTime);
                //readThreadInfo(file);
            }
        }
    }


    private static int flagNum = 0;
    /**
     * 写入文件信息
     * @param printWriter
     * @param thread
     * @param state
     */
    private static void writeThreadInfo(PrintWriter printWriter,Thread thread,Thread.State state){
        System.out.println("+++++++++ing+++++++++++"+(++flagNum));
        printWriter.printf("*******************Name=%s****************************\n",thread.getName());
        printWriter.printf("Main：Id：%d - Name：%s\n",thread.getId(),thread.getName());
        printWriter.printf("Main：Priority：%d\n", thread.getPriority());
        printWriter.printf("Main：Old State：%s\n", state);
        printWriter.printf("Main：New State：%s\n", thread.getState());
        printWriter.printf("*******************Name=%s****************************\n\n",thread.getName());
    }


    /**
     * 读取文件输出控制台
     * @param file
     */
    private static void readThreadInfo(File file){
        String str= null;
        FileReader fileReader = null;
        BufferedReader bufferedReader = null;
        try {
            fileReader = new FileReader(file);
            bufferedReader = new BufferedReader(fileReader);
            while((str=bufferedReader.readLine())!=null){
                System.out.printf("%s\n", str);
            }
        } catch (Exception e) {
            e.printStackTrace();  //To change body of catch statement use File | Settings | File Templates.
        }finally {
            if(bufferedReader!=null){
                try {
                    bufferedReader.close();
                } catch (IOException e) {
                    e.printStackTrace();  //To change body of catch statement use File | Settings | File Templates.
                }
            }
            if(fileReader!=null){
                try {
                    fileReader.close();
                } catch (IOException e) {
                    e.printStackTrace();  //To change body of catch statement use File | Settings | File Templates.
                }
            }
        }
    }


}

3、部分运行结果

（1）控制台结果

java其他线程获取main线程的状态 java获取线程名_优先级