自己实现简单java缓存类文件_java怎么把数据存到缓存中

import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;
/** * @Author: lixk * @Date: 2018/5/9 15:03 * @Description: 简单的内存缓存工具类 */
public class Cache { 

/** * 键值对集合 */
private final static Map<String, Entity> map = new HashMap<>();
/** * 定时器线程池，用于清除过期缓存 */
private final static ScheduledExecutorService executor = Executors.newSingleThreadScheduledExecutor();
/** * 添加缓存 * * @param key 键 * @param data 值 */
public synchronized static void put(String key, Object data) { 

Cache.put(key, data, 0);
}
/** * 添加缓存 * * @param key 键 * @param data 值 * @param expire 过期时间，单位：毫秒， 0表示无限长 */
public synchronized static void put(String key, Object data, long expire) { 

//清除原键值对
Cache.remove(key);
//设置过期时间
if (expire > 0) { 

Future future = executor.schedule(new Runnable() { 

@Override
public void run() { 

//过期后清除该键值对
synchronized (Cache.class) { 

map.remove(key);
}
}
}, expire, TimeUnit.MILLISECONDS);
map.put(key, new Entity(data, future));
} else { 

//不设置过期时间
map.put(key, new Entity(data, null));
}
}
/** * 读取缓存 * * @param key 键 * @return */
public synchronized static <T> T get(String key) { 

Entity entity = map.get(key);
return entity == null ? null : (T) entity.value;
}
/** * 清除缓存 * * @param key 键 * @return */
public synchronized static <T> T remove(String key) { 

//清除原缓存数据
Entity entity = map.remove(key);
if (entity == null) { 

return null;
}
//清除原键值对定时器
if (entity.future != null) { 

entity.future.cancel(true);
}
return (T) entity.value;
}
/** * 查询当前缓存的键值对数量 * * @return */
public synchronized static int size() { 

return map.size();
}
/** * 缓存实体类 */
private static class Entity { 

/** * 键值对的value */
public Object value;
/** * 定时器Future */
public Future future;
public Entity(Object value, Future future) { 

this.value = value;
this.future = future;
}
}
}

import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.atomic.AtomicInteger;
/** * @Author: lixk * @Date: 2018/5/9 16:40 * @Description: 缓存工具类测试 */
public class CacheTest { 

/** * 测试 * * @param args */
public static void main(String[] args) throws InterruptedException { 

String key = "id";
//不设置过期时间
System.out.println("***********不设置过期时间**********");
Cache.put(key, 123);
System.out.println("key:" + key + ", value:" + Cache.get(key));
System.out.println("key:" + key + ", value:" + Cache.remove(key));
System.out.println("key:" + key + ", value:" + Cache.get(key));
//设置过期时间
System.out.println("\n***********设置过期时间**********");
Cache.put(key, "123456", 1000);
System.out.println("key:" + key + ", value:" + Cache.get(key));
Thread.sleep(2000);
System.out.println("key:" + key + ", value:" + Cache.get(key));
System.out.println("\n***********100w读写性能测试************");
//创建有10个线程的线程池，将1000000次操作分10次添加到线程池
int threads = 10;
ExecutorService pool = Executors.newFixedThreadPool(threads);
//每批操作数量
int batchSize = 100000;
//添加
{ 

CountDownLatch latch = new CountDownLatch(threads);
AtomicInteger n = new AtomicInteger(0);
long start = System.currentTimeMillis();
for (int t = 0; t < threads; t++) { 

pool.submit(() -> { 

for (int i = 0; i < batchSize; i++) { 

int value = n.incrementAndGet();
Cache.put(key + value, value, 300000);
}
latch.countDown();
});
}
//等待全部线程执行完成，打印执行时间
latch.await();
System.out.printf("添加耗时：%dms\n", System.currentTimeMillis() - start);
}
//查询
{ 

CountDownLatch latch = new CountDownLatch(threads);
AtomicInteger n = new AtomicInteger(0);
long start = System.currentTimeMillis();
for (int t = 0; t < threads; t++) { 

pool.submit(() -> { 

for (int i = 0; i < batchSize; i++) { 

int value = n.incrementAndGet();
Cache.get(key + value);
}
latch.countDown();
});
}
//等待全部线程执行完成，打印执行时间
latch.await();
System.out.printf("查询耗时：%dms\n", System.currentTimeMillis() - start);
}
System.out.println("当前缓存容量：" + Cache.size());
}
}

***********不设置过期时间**********
key:id, value:123
key:id, value:123
key:id, value:null
***********设置过期时间**********
key:id, value:123456
key:id, value:null
***********100w读写性能测试************
添加耗时：1729ms
查询耗时：283ms
当前缓存容量：1000000