多线程数据库

import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

public class ThreadSafeCounter {
    private int count = 0;
    private final Lock lock = new ReentrantLock();

    public void increment() {
        lock.lock();
        try {
            count++;
        } finally {
            lock.unlock();
        }
    }

    public int getCount() {
        return count;
    }
}

import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

public class DeadlockAvoidance {
    private final Lock lock1 = new ReentrantLock();
    private final Lock lock2 = new ReentrantLock();

    public void method1() throws InterruptedException {
        if (lock1.tryLock(1, TimeUnit.SECONDS)) {
            try {
                if (lock2.tryLock(1, TimeUnit.SECONDS)) {
                    try {
                        // 执行操作
                    } finally {
                        lock2.unlock();
                    }
                }
            } finally {
                lock1.unlock();
            }
        }
    }

    public void method2() throws InterruptedException {
        if (lock2.tryLock(1, TimeUnit.SECONDS)) {
            try {
                if (lock1.tryLock(1, TimeUnit.SECONDS)) {
                    try {
                        // 执行操作
                    } finally {
                        lock1.unlock();
                    }
                }
            } finally {
                lock2.unlock();
            }
        }
    }
}