Java--线程的互斥实现（两种方法）

我们是利用synchronized的两种方法：声明一条语句或声明一个方法

方法——：同步语句，使用synchronized(对象)后面接语句即可

方法二 同步方法，使用synchronized（this）{ 方法体 }

附方法一代码如下：

package AcountThread;

public class Account {
  String name;
  private int balance;

  public String getName() {
    return name;
  }

  public int getBalance() {
    return balance;
  }

  public Account(String name) {
    this.name = name;
    this.balance = 0;
  }

  // 存钱
  public void put(int value) { // value为存入金额
    if (value > 0) {
      this.balance += value;
    }
  }

  // 取钱方法
  public double get(int value) {
    if (value > 0) {
      if (value < this.balance) {
        this.balance -= value;
      } else {
        value = this.balance; // 取走所有余额
        this.balance = 0;
      }
    }
    return value;
  }
}

package AcountThread;

public class FecthThread extends Thread {
  public Account account;
  public int value;

  public FecthThread(Account account, int value) {
    this.account = account;
    this.value = value;
  }

  public void run() {
    synchronized (account) {  //拿锁对象

      // 查看余额
      double howmatch = this.account.getBalance();
      // 取钱
      double v = this.account.get(value);
      // 查看余额
      System.out.println(this.account.name + "账户：现有" + howmatch + ",取走"
          + v + ",余额" + this.account.getBalance());

    } // 解锁对象
  }
}

package AcountThread;

public class SevaThread extends Thread {
  public Account account;
  public int value;

  public SevaThread(Account account, int value) {
    this.account = account;
    this.value = value;
  }

  public void run() {
    synchronized (account) {
      // 查看
      double howmatch = this.account.getBalance();
      // 存钱
      this.account.put(value);
      // 查看
      System.out.println(account.getName() + "账户：现有" + howmatch + ",存入"
          + this.value + "，余额" + this.account.getBalance());
      ;
    }
  }
}


package AcountThread;

public class MainThread {

  public static void main(String[] args) {
    Account wang = new Account("wang");
    (new SevaThread(wang, 100)).start();// 匿名对象等价于SevaThred t1 = new
                // SevaThread(wang,
                // 100);t1.start();
    (new SevaThread(wang, 200)).start();
    (new FecthThread(wang, 300)).start();

  }

}

附方法一代码如下：package AcountThread.v2;

public class Account {
  private String name;
  private int balance;

  public String getName() {
    return name;
  }

  public int getBalance() {
    return balance;
  }

  public Account(String name) {
    this.name = name;
    this.balance = 0;
  }

  // 存钱方法
  synchronized public void put(int value) { // value为存入金额

    if (value > 0) {
      double howmatch = balance; // 查看起初的金额
      this.balance += value;

      System.out.println(name + "账户：现有" + howmatch + ",存入" + value
          + "，余额" + balance);
      ;
    }

  }

  // 取钱方法
  synchronized public void get(int value) {

    int howmatch = balance; // 查看余额

    if (value > 0) {
      if (value < this.balance) {
        this.balance -= value; //
      } else {
        value = this.balance; // 取走所有余额
        this.balance = 0;
      }
    }

    System.out.println(name + "账户：现有" + howmatch + ",取走" + value + ",余额"
        + balance);

  }
}
package AcountThread.v2;

public class FecthThread extends Thread {
  public Account account;
  public int value;

  public FecthThread(Account account, int value) {
    this.account = account;
    this.value = value;
  }

  public void run() {
    // 取钱
    this.account.get(value);
  }
}
package AcountThread.v2;

public class SevaThread extends Thread {
  public Account account;
  public int value;

  public SevaThread(Account account, int value) {
    this.account = account;
    this.value = value;
  }

  public void run() {
    // 存钱
    this.account.put(value);

  }
}

package AcountThread.v2;

public class MainThread {

  public static void main(String[] args) {
    Account wang = new Account("wang");

    (new SevaThread(wang, 100)).start(); // 匿名对象等价于SevaThred t1 = new
                 // SevaThread(wang,
                 // 100);t1.start();
    (new SevaThread(wang, 200)).start();
    (new FecthThread(wang, 300)).start();

  }

}