What is the concept of java read-write lock

This article mainly introduces the concept of java read-write lock is what the relevant knowledge, detailed and easy to understand, simple and fast operation, with a certain reference value, I believe that everyone reading this java read-write lock concept is what the article will have some harvest, let's take a look at it.

Read-write locks divide access to a resource (such as a file) into two locks, one read-write lock.

Because of read-write locks, read and write operations between multiple threads will not conflict.

ReadWriteLock is a read-write lock, it is an interface, RentrantReadWriteLock implements this interface.

examples

public class CacheDemo { private Map cache = new HashMap(); private ReadWriteLock readWriteLock = new ReentrantReadWriteLock(); public static void main(String[] args) { } public Object getData(String key) { Object value = null; //First open the read lock and fetch from the cache readWriteLock.readLock().lock(); try { value = cache.get(key); //If no read lock is released in cache, unwrite lock if (value == null) { //corresponds to queryDB() readWriteLock.readLock().unlock(); //Read lock must be unlocked before write lock can be acquired readWriteLock.writeLock().lock(); try { //corresponds to queryDB() value = queryDB(); } finally { //release write lock readWriteLock.writeLock().unlock(); } //and then read the lock again readWriteLock.readLock().lock(); } } finally { //finally release read lock readWriteLock.readLock().unlock(); } return value; } public Object queryDB() { return "aaaa"; }} About "Java read-write lock concept is what" the content of this article is introduced here, thank you for reading! I believe that everyone has a certain understanding of the "java read-write lock concept" knowledge, if you still want to learn more knowledge, welcome to pay attention to the industry information channel.