/* ServiceWrapperInterceptor.java
*
* Copyright 2009-2012 Comcast Interactive Media, LLC.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.fishwife.jrugged.spring;
import java.util.Map;
import java.util.concurrent.Callable;
import org.aopalliance.intercept.MethodInterceptor;
import org.aopalliance.intercept.MethodInvocation;
import org.fishwife.jrugged.CircuitBreaker;
import org.fishwife.jrugged.PerformanceMonitor;
import org.fishwife.jrugged.ServiceWrapper;
/**
* A Spring interceptor that allows wrapping a method invocation with
* a {@link ServiceWrapper} (for example, a {@link CircuitBreaker} or
* {@link PerformanceMonitor}).
*/
public class ServiceWrapperInterceptor implements MethodInterceptor {
private Map<String, ServiceWrapper> methodMap;
/** See if the given method invocation is one that needs to be
* called through a {@link ServiceWrapper}, and if so, do so.
* @param invocation the {@link MethodInvocation} in question
* @return whatever the underlying method call would normally
* return
* @throws Throwable that the method call would generate, or
* that the {@link ServiceWrapper} would generate when tripped.
*/
public Object invoke(final MethodInvocation invocation) throws Throwable {
String methodName = invocation.getMethod().getName();
if (!shouldWrapMethodCall(methodName)) {
return invocation.proceed();
}
else {
ServiceWrapper wrapper = methodMap.get(methodName);
return wrapper.invoke(new Callable<Object>() {
public Object call() throws Exception {
try {
return invocation.proceed();
} catch (Throwable e) {
if (e instanceof Exception)
throw (Exception) e;
else if (e instanceof Error)
throw (Error) e;
else
throw new RuntimeException(e);
}
}
});
}
}
private boolean shouldWrapMethodCall(String methodName) {
if (methodMap == null) {
return true; // Wrap all by default
}
if (methodMap.get(methodName) != null) {
return true; //Wrap a specific method
}
// If I get to this point, I should not wrap the call.
return false;
}
/** Specifies which methods will be wrapped with which ServiceWrappers.
* @param methodMap the mapping!
*/
public void setMethods(Map<String, ServiceWrapper> methodMap) {
this.methodMap = methodMap;
}
}