import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
public class SimpleCache<t> {
private final Map<string> m_objects;
private final Map<string> m_expiredObjects;
private final long m_lExpireTime;
private final ExecutorService m_executor;
public SimpleCache() {
this(500);
}
public SimpleCache(final int nExpireTime) {
m_objects = Collections.synchronizedMap(new HashMap<string>());
m_expiredObjects = Collections.synchronizedMap(new HashMap<string>());
m_lExpireTime = nExpireTime;
m_executor = Executors.newFixedThreadPool(256);
Executors.newScheduledThreadPool(5).scheduleWithFixedDelay(RemoveExpiredObjects(), m_lExpireTime / 2,
m_lExpireTime, TimeUnit.SECONDS);
}
private final Runnable RemoveExpiredObjects() {
return new Runnable() {
public void run() {
for (final String name : m_expiredObjects.keySet()) {
if (System.currentTimeMillis() > m_expiredObjects.get(name)) {
m_executor.execute(CreateRemoveRunnable(name));
}
}
}
};
}
private final Runnable CreateRemoveRunnable(final String name) {
return new Runnable() {
public void run() {
m_objects.remove(name);
m_expiredObjects.remove(name);
}
};
}
public long GetExpireTime() {
return m_lExpireTime;
}
public void Put(final String name, final T obj) {
Put(name, obj, m_lExpireTime);
}
public void Put(final String name, final T obj, final long expireTime) {
m_objects.put(name, obj);
m_expiredObjects.put(name, System.currentTimeMillis() + expireTime * 1000);
}
public T Get(final String name) {
final Long expireTime = m_expiredObjects.get(name);
if (expireTime == null)
return null;
if (System.currentTimeMillis() > expireTime) {
m_executor.execute(CreateRemoveRunnable(name));
return null;
}
return m_objects.get(name);
}
@SuppressWarnings("unchecked")
public <r> R Get(final String name, final Class<r> type) {
return (R) Get(name);
}
}</r></r></string></string></string></string></t>
Java免费学习笔记：立即使用
解锁 Java 大师之旅：从入门到精通的终极指南
