com.xiaoleilu.hutool.lang.SimpleCache Maven / Gradle / Ivy
package com.xiaoleilu.hutool.lang;
import java.util.Map;
import java.util.WeakHashMap;
import java.util.concurrent.locks.ReentrantReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock.ReadLock;
import java.util.concurrent.locks.ReentrantReadWriteLock.WriteLock;
/**
* 简单缓存，无超时实现，使用{@link WeakHashMap}实现缓存自动清理
* @author Looly
*
* @param 键类型
* @param 值类型
*/
public class SimpleCache {
/** 池 */
private final Map cache = new WeakHashMap<>();
private final ReentrantReadWriteLock cacheLock = new ReentrantReadWriteLock();
private final ReadLock readLock = cacheLock.readLock();
private final WriteLock writeLock = cacheLock.writeLock();
/**
* 从缓存池中查找值
*
* @param key 键
* @return 值
*/
public V get(K key) {
// 尝试读取缓存
readLock.lock();
V value;
try {
value = cache.get(key);
} finally {
readLock.unlock();
}
return value;
}
/**
* 放入缓存
* @param key 键
* @param value 值
* @return 值
*/
public V put(K key, V value){
writeLock.lock();
try {
cache.put(key, value);
} finally {
writeLock.unlock();
}
return value;
}
/**
* 移除缓存
*
* @param key 键
* @return 移除的值
*/
public V remove(K key) {
writeLock.lock();
try {
return cache.remove(key);
} finally {
writeLock.unlock();
}
}
/**
* 清空缓存池
*/
public void clear() {
writeLock.lock();
try {
this.cache.clear();
} finally {
writeLock.unlock();
}
}
}