org.zkybase.kite.circuitbreaker.interceptor.CircuitBreakerSourcePointcut.java Source code

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Here is the source code for org.zkybase.kite.circuitbreaker.interceptor.CircuitBreakerSourcePointcut.java

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/*
 * Copyright (c) 2010 the original author or authors.
 *
 * 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.zkybase.kite.circuitbreaker.interceptor;

import java.io.Serializable;
import java.lang.reflect.Method;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.aop.support.StaticMethodMatcherPointcut;
import org.springframework.util.ObjectUtils;

/**
 * <p>
 * A circuit breaker pointcut that matches iff the underlying source has a breaker for the given method. 
 * </p>
 * 
 * @author Willie Wheeler
 * @since 1.0
 */
@SuppressWarnings("serial")
public class CircuitBreakerSourcePointcut extends StaticMethodMatcherPointcut implements Serializable {

    private static Logger log = LoggerFactory.getLogger(CircuitBreakerSourcePointcut.class);

    private CircuitBreakerSource source;

    public CircuitBreakerSource getSource() {
        return source;
    }

    public void setSource(CircuitBreakerSource source) {
        this.source = source;
    }

    /**
     * @param method
     *            method to evaluate
     * @param targetClass
     *            target class to evaluate (if <code>null</code>, then we
     *            evaluate against the method's declaring class
     * @return boolean indicating whether the target method is eligible for
     *         advice
     */
    public boolean matches(Method method, Class<?> targetClass) {
        if (source == null) {
            throw new IllegalStateException("source can't be null");
        }

        // Hm, the existence of a circuit breaker source is actually runtime
        // information, not static. Does that violate the spirit of the
        // StaticMethodMatcher contract? (The contract states explicitly that
        // we won't get runtime info about the method call, but I don't think it
        // says anything about other runtime information...) At any rate, it
        // definitely wouldn't make any sense to declare this as a
        // DynamicMethodMatcherPointcut since the method arguments never matter.
        boolean match = source.getBreaker(method, targetClass) != null;
        if (match) {
            Class<?> clazz = (targetClass != null ? targetClass : method.getDeclaringClass());
            log.debug("Found pointcut match for {}.{}", clazz.getName(), method.getName());
        }
        return match;
    }

    @Override
    public boolean equals(Object other) {
        if (this == other) {
            return true;
        }
        if (!(other instanceof CircuitBreakerSourcePointcut)) {
            return false;
        }
        CircuitBreakerSourcePointcut otherPc = (CircuitBreakerSourcePointcut) other;
        return ObjectUtils.nullSafeEquals(source, otherPc.source);
    }

    @Override
    public int hashCode() {
        return CircuitBreakerSourcePointcut.class.hashCode();
    }

    @Override
    public String toString() {
        return getClass().getName() + ": " + source;
    }
}