ReadWriteLock readWriteLock = new ReentrantReadWriteLock();

ReadWriteLock readWriteLock = new ReentrantReadWriteLock();
readWriteLock.readLock().lock();

ReadWriteLock readWriteLock = new ReentrantReadWriteLock();
readWriteLock.readLock().tryLock();
readWriteLock.readLock().tryLock(6L, TimeUnit.SECONDS);

ReadWriteLock readWriteLock = new ReentrantReadWriteLock();
readWriteLock.writeLock().lock();

ReadWriteLock readWriteLock = new ReentrantReadWriteLock();
readWriteLock.writeLock().tryLock();
readWriteLock.writeLock().tryLock(6L, TimeUnit.SECONDS);

public class LockManager {
    private final ReadWriteLock readWriteLock = new ReentrantReadWriteLock();
    public void write(String message,Long sleep) {
        try{
            if(readWriteLock.writeLock().tryLock()){
                try{
                    Thread.sleep(sleep);
                    System.out.println(Thread.currentThread().getName()+",寫(xiě)寫(xiě)寫(xiě)寫(xiě)寫(xiě)寫(xiě)寫(xiě)寫(xiě)寫(xiě)寫(xiě)，message="+message);
                }catch (Exception ex){
                    System.out.println(Thread.currentThread().getName()+",寫(xiě)入異常"+ex);
                }finally {
                    readWriteLock.writeLock().unlock();
                }
            }else{
                System.out.println(Thread.currentThread().getName()+",獲取寫(xiě)鎖失敗");
            }
        }catch (Exception ex){
            ex.printStackTrace();
        }
    }
    public void read(String message,Long sleep){
        try{
            if(readWriteLock.readLock().tryLock(6L, TimeUnit.SECONDS)){
                try{
                    Thread.sleep(sleep);
                    System.out.println(Thread.currentThread().getName()+",讀讀讀讀讀讀讀讀讀讀，message="+message);
                }catch (Exception ex){
                    System.out.println(Thread.currentThread().getName()+",讀取異常"+ex);
                }finally {
                    readWriteLock.readLock().unlock();
                }
            }else{
                System.out.println(Thread.currentThread().getName()+",獲取讀鎖失敗");
            }
        }catch (Exception ex){
            ex.printStackTrace();
        }
    }
}

@Test
public void testOnlyRead() throws Exception {
    LockManager lockManager = new LockManager();
    new Thread(()->lockManager.read("001",5000L)).start();
    new Thread(()->lockManager.read("002",4000L)).start();
    Thread.sleep(20000L);
}

@Test
public void testOnlyWrite() throws Exception {
    LockManager lockManager = new LockManager();
    new Thread(()->lockManager.write("001",5000L)).start();
    new Thread(()->lockManager.write("002",4000L)).start();
    Thread.sleep(20000L);
}

@Test
public void testReadWrite() throws Exception {
    LockManager lockManager = new LockManager();
    new Thread(()->lockManager.read("001",5000L)).start();
    new Thread(()->lockManager.write("002",4000L)).start();
    Thread.sleep(20000L);
}

@Test
public void testWriteRead() throws Exception {
    LockManager lockManager = new LockManager();
    new Thread(()->lockManager.write("001",5000L)).start();
    new Thread(()->lockManager.read("002",4000L)).start();
    Thread.sleep(20000L);
}