0.线程的生命周期
1.java实现多线程方式一：
2.java实现多线程方式二：
3.两种方式的比较：
package ThreadCompare;
public class MyThreadByRunnable implements Runnable {
private int ticket =
5;
@Override
public void run() {
while(ticket>
0) {
ticket--;
System.out.println(
MyThreadByThread.currentThread().getName()+
"卖了1张票，还剩"+ticket+
"张");
}
}
}
package ThreadCompare;
public class MyThreadByThread extends Thread {
private int ticket =
5;
@Override
public void run() {
while(ticket>
0) {
ticket--;
System.out.println(
MyThreadByThread.currentThread().getName()+
"卖了1张票，还剩"+ticket+
"张");
}
}
}
package ThreadCompare;
import java.util.Scanner;
public class MainTest {
public void testThread() {
MyThreadByThread mt1 =
new MyThreadByThread();
MyThreadByThread mt2 =
new MyThreadByThread();
MyThreadByThread mt3 =
new MyThreadByThread();
mt1.start();
mt2.start();
mt3.start();
}
public void testRunnable() {
MyThreadByRunnable mt =
new MyThreadByRunnable();
Thread t1 =
new Thread(mt,
"窗口1");
Thread t2 =
new Thread(mt,
"窗口2");
Thread t3 =
new Thread(mt,
"窗口3");
t1.start();
t2.start();
t3.start();
}
public void demonThreadTest() {
System.out.println(
"*********主线程开始执行了*********");
DemonThread dt =
new DemonThread();
Thread t =
new Thread(dt,
"demon");
t.setDaemon(
true);
t.start();
Scanner sc =
new Scanner(System.in);
sc.next();
System.out.println(
"*********主线程执行结束了*********");
}
public static void main(String[] args) {
new MainTest().demonThreadTest();
}
}
执行new MainTest().testRunnable()结果
执行new MainTest().testThread()结果
所以：
Runnable方式可以避免java单继承带来的缺陷，想实现就直接实现接口即可 Runnable实现的线程都是可以由该接口来进行连接，适用于多个线程处理同一个Runnable对象的情况
4.守护线程
Runnable实现方式设置守护线程 通过setDemon（true）方法实现（代码如上所示）。
package ThreadCompare;
public class DemonThread implements Runnable {
private int count =
0;
@Override
public void run() {
System.out.println(
"*********守护线程开始执行了*********");
while (count<
100) {
count++;
System.out.println(
"线程执行了 "+count+
" 次");
try {
Thread.sleep(
1000);
}
catch (InterruptedException e) {
e.printStackTrace();
}
}
System.out.println(
"*********守护线程执行结束了*********");
}
}
守护线程：
5.线程同步—synchronized用法
分析：
给方法加synchronized 会使得整个方法都是在锁保护（或者叫同步控制）之内，当方法较为冗长时开销较大 只给特定代码块添加synchronized效率高
