JAVA学习笔记-常用功能模块代码

多线程

package pack1;

class RunnableDemo implements Runnable {
    private Thread t;
    private String threadName;

    RunnableDemo(String name) {
        threadName = name;
        System.out.println("Creating " + threadName);
    }

    public void run() {
        System.out.println("Running " + threadName);
        try {
            for (int i = 4; i > 0; i--) {
                System.out.println("Thread: " + threadName + ", " + i);
                // 让线程睡眠一会
                Thread.sleep(50);
            }
        } catch (InterruptedException e) {
            System.out.println("Thread " + threadName + " interrupted.");
        }
//        System.out.println("Thread " + threadName + " exiting.");
    }

    public void start() {
//        System.out.println("Starting " + threadName);
//        if (t == null) {
            t = new Thread(this, threadName);
            t.start();
//        }
    }
}

public class TestThread {

    public static void main(String args[]) {
        RunnableDemo R1 = new RunnableDemo("Thread-1");
        R1.start();

        RunnableDemo R2 = new RunnableDemo("Thread-2");
        R2.start();
    }
}

文件写入内容

import java.io.*;

public class WriteFile {
    public static void main(String[] args)  {
        try {
            BufferedWriter out = new BufferedWriter(new FileWriter("runoob.txt"));
　　　　　　　　// 若是追加数据，则 在文件名 的后面再添加一个 参数  true 
            out.write("菜鸟教程");
            out.close();
            System.out.println("文件创建成功！");
        } catch (IOException e) {
        }
    }
}

读取文件内容

import java.io.*;

public class WriteFile {
    public static void main(String[] args)  {
        try {
            BufferedReader in = new BufferedReader(new FileReader("test.log"));
            String str;

            while ((str = in.readLine()) != null) {
                System.out.println(str);
            }
            System.out.println(str);
        } catch (IOException e) {
        }
    }
}

更多常用模块功能 https://www.runoob.com/java/java-examples.html