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import java.io.Serializable;
import net.sf.ehcache.Cache;
import net.sf.ehcache.Element;
import org.aopalliance.intercept.MethodInterceptor;
import org.aopalliance.intercept.MethodInvocation;
import org.springframework.beans.factory.InitializingBean;
/**
* 攔截器,用于緩存方法返回結果.
*
* @version $Id: MethodCacheInterceptor.java v 1.0 2004-11-28 14:57:00 Znjq Exp $
* @author <a href="mailto:znjq1980@etang.com">Znjq </a>
*/
public class MethodCacheInterceptor implements MethodInterceptor,
InitializingBean {
private Cache cache;
/**
* sets cache name to be used
*/
public void setCache(Cache cache) {
this.cache = cache;
}
/*
* (non-Javadoc)
*
* @see org.aopalliance.intercept.MethodInterceptor#invoke(org.aopalliance.intercept.MethodInvocation)
*/
public Object invoke(MethodInvocation invocation) throws Throwable {
String targetName = invocation.getThis().getClass().getName();
String methodName = invocation.getMethod().getName();
Object[] arguments = invocation.getArguments();
Object result;
String cacheKey = getCacheKey(targetName, methodName, arguments);
Element element = cache.get(cacheKey);
if (element == null) {
//call target/sub-interceptor
result = invocation.proceed();
//cache method result
element = new Element(cacheKey, (Serializable) result);
cache.put(element);
}
return element.getValue();
}
/**
* creates cache key: targetName.methodName.argument0.argument1...
*/
private String getCacheKey(String targetName, String methodName,
Object[] arguments) {
StringBuffer sb = new StringBuffer();
sb.append(targetName).append(".").append(methodName);
if ((arguments != null) && (arguments.length != 0)) {
for (int i = 0; i < arguments.length; i++) {
sb.append(".").append(arguments[i]);
}
}
return sb.toString();
}
/*
* (non-Javadoc)
*
* @see org.springframework.beans.factory.InitializingBean#afterPropertiesSet()
*/
public void afterPropertiesSet() throws Exception {
// TODO Auto-generated method stub
}
} |