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();

	}

}