package com.pccw.hessian.support.cache;
import java.lang.reflect.Method;
import java.util.HashMap;
import com.pccw.hessian.support.cache.CacheHandler;
import com.pccw.hessian.support.cache.CachePolicy;
public class DefaultCacheHandler implements CacheHandler{
private class CacheContainner{
long brith;
Object obj;
public CacheContainner(long brith,Object obj) {
this.brith=brith;
this.obj=obj;
}
}
private HashMap<String,CacheContainner> cache=new HashMap<String, CacheContainner>();
//不需要判断policy为null,policy为null,认定为不适用缓存，不会掉用此方法
@Override
public boolean ifReturnFromCahce(Method method, Object[] args) {
CachePolicy policy=method.getAnnotation(CachePolicy.class);
if(policy.expires() < 0){
System.out.println("没有有效期,false");
return false;
}
try {
String key=getCacheKey(method,args);
//String key=policy.keyGenerater().newInstance().generatKey(method, args);System.out.println("生成的缓存key:"+key);
if(cache.containsKey(key)==false){System.out.println("有缓存规则,但缓存中不存在false");
return false;
}
CacheContainner cc=cache.get(key);
if((System.currentTimeMillis()-cc.brith) < policy.expires()){System.out.println("有缓存规则,且缓存中存在,且没过期true");
return true;
}
} catch (Exception e) {
e.printStackTrace();
}
System.out.println("有缓存规则,且缓存中存在,但可能过期,false");
return false;
}
@Override
public Object returnFromCahce(Method method, Object[] args) {
try {
String key=getCacheKey(method,args);
System.out.println("从缓存中获取");
CacheContainner cc=cache.get(key);
return cc==null?null:cc.obj;
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
@Override
public void onExecuteSuccess(Method method, Object[] args, Object result) {
try {
String key=getCacheKey(method,args);
System.out.println("放入缓存:"+key);
cache.put(key, new CacheContainner(System.currentTimeMillis(), result));
} catch (Exception e) {
e.printStackTrace();
}
}
private String getCacheKey(Method method, Object[] args) throws InstantiationException, IllegalAccessException{
CachePolicy policy=method.getAnnotation(CachePolicy.class);
return "".equals(policy.key())?policy.keyGenerater().newInstance().generatKey(method, args):policy.key();
}
}