JAVA---创建线程的4种方式

1.创建线程的4种方式

方式一：

继承Thread,缺点，java是单继承，如果继承了Thread就不能继承其他类

方式二：

实现runnable()接口，通常不直接在类上实现runnable接口，与类的耦合度高

方式三：实现callable()接口 和futrue使用

与实现runnable接口相比，callable()有返回值，且自带异常处理

方式四：使用线程池

2.各种锁的java实现方式

 通俗易懂 悲观锁、乐观锁、可重入锁、自旋锁、偏向锁、轻量/重量级锁、读写锁、各种锁及其Java实现！

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ThreadDemo类

package com.javasm;

import java.io.Serializable;
import java.util.concurrent.TimeUnit;

public class UserInfo {

    final Object object = new Object();
    private Integer age;
    private String name;
    private Integer balance;

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Integer getBalance() {
        return balance;
    }

    public void setBalance(Integer balance) {
        this.balance = balance;
    }

    public UserInfo(Integer age, String name, Integer balance) {
        this.age = age;
        this.name = name;
        this.balance = balance;
    }

    public boolean isFlag() {
        return flag;
    }

    public void setFlag(boolean flag) {
        this.flag = flag;
    }

    protected boolean flag = true;
    int count = 0;

    public void getMoney() {


        while (flag) {
            synchronized (this) {
                if (balance <= 0) {
                    System.out.println("余额不足");
                    flag = false;
                    return;
                }
                count++;
                balance -= 1000;
                System.out.println(Thread.currentThread().getName() + "取走了"+name+"1000元" + "剩余：" + balance + "-" + "第" + count + "次取钱");
            }
            try {
                TimeUnit.SECONDS.sleep(3);
            } catch (InterruptedException e) {
                throw new RuntimeException(e);
            }

        }

    }

    public void setMoney() {
        balance += 1000;
        System.out.println(Thread.currentThread().getName() + "往账户存入1000" + "剩余：" + balance+"元");
        try {
            TimeUnit.SECONDS.sleep(1);
        } catch (InterruptedException e) {
            throw new RuntimeException(e);
        }


    }
}

--------------------------

UserInfo类

package com.javasm;

import java.io.Serializable;
import java.util.concurrent.TimeUnit;

public class UserInfo {

    final Object object = new Object();
    private Integer age;
    private String name;
    private Integer balance;

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Integer getBalance() {
        return balance;
    }

    public void setBalance(Integer balance) {
        this.balance = balance;
    }

    public UserInfo(Integer age, String name, Integer balance) {
        this.age = age;
        this.name = name;
        this.balance = balance;
    }

    public boolean isFlag() {
        return flag;
    }

    public void setFlag(boolean flag) {
        this.flag = flag;
    }

    protected boolean flag = true;
    int count = 0;

    public void getMoney() {


        while (flag) {
            synchronized (this) {
                if (balance <= 0) {
                    System.out.println("余额不足");
                    flag = false;
                    return;
                }
                count++;
                balance -= 1000;
                System.out.println(Thread.currentThread().getName() + "取走了"+name+"1000元" + "剩余：" + balance + "-" + "第" + count + "次取钱");
            }
            try {
                TimeUnit.SECONDS.sleep(3);
            } catch (InterruptedException e) {
                throw new RuntimeException(e);
            }

        }

    }

    public void setMoney() {
        balance += 1000;
        System.out.println(Thread.currentThread().getName() + "往账户存入1000" + "剩余：" + balance+"元");
        try {
            TimeUnit.SECONDS.sleep(1);
        } catch (InterruptedException e) {
            throw new RuntimeException(e);
        }


    }
}

2.如何解决线程安全问题？