com.payu.ratel.client.ContextAnnotationAutowireCandidateResolver.java Source code

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Here is the source code for com.payu.ratel.client.ContextAnnotationAutowireCandidateResolver.java

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/*
 * Copyright 2015 PayU
 *
 * 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 com.payu.ratel.client;

import org.springframework.aop.TargetSource;
import org.springframework.aop.framework.ProxyFactory;
import org.springframework.beans.factory.annotation.QualifierAnnotationAutowireCandidateResolver;
import org.springframework.beans.factory.config.DependencyDescriptor;
import org.springframework.beans.factory.support.DefaultListableBeanFactory;
import org.springframework.context.annotation.Lazy;
import org.springframework.core.MethodParameter;
import org.springframework.core.annotation.AnnotationUtils;
import org.springframework.util.Assert;

import java.lang.annotation.Annotation;
import java.lang.reflect.Method;

/**
 * Complete implementation of the
 * {@link org.springframework.beans.factory.support.AutowireCandidateResolver} strategy
 * interface, providing support for qualifier annotations as well as for lazy resolution
 * driven by the {@link org.springframework.context.annotation.Lazy} annotation in the {@code context.annotation} package.
 *
 * @author Juergen Hoeller
 * @since 4.0
 * Backport to Spring 3
 */
class ContextAnnotationAutowireCandidateResolver extends QualifierAnnotationAutowireCandidateResolver {

    @Override
    public Object getLazyResolutionProxyIfNecessary(DependencyDescriptor descriptor, String beanName) {
        return (isLazy(descriptor) ? buildLazyResolutionProxy(descriptor, beanName) : null);
    }

    protected boolean isLazy(DependencyDescriptor descriptor) {
        for (Annotation ann : descriptor.getAnnotations()) {
            Lazy lazy = AnnotationUtils.getAnnotation(ann, Lazy.class);
            if (lazy != null && lazy.value()) {
                return true;
            }
        }
        MethodParameter methodParam = descriptor.getMethodParameter();
        if (methodParam == null) {
            return false;
        }
        Method method = methodParam.getMethod();
        if (method == null || void.class.equals(method.getReturnType())) {
            Lazy lazy = AnnotationUtils.getAnnotation(methodParam.getAnnotatedElement(), Lazy.class);
            if (lazy != null && lazy.value()) {
                return true;
            }
        }

        return false;
    }

    protected Object buildLazyResolutionProxy(final DependencyDescriptor descriptor, final String beanName) {
        Assert.state(getBeanFactory() instanceof DefaultListableBeanFactory,
                "BeanFactory needs to be a DefaultListableBeanFactory");
        final DefaultListableBeanFactory beanFactory = (DefaultListableBeanFactory) getBeanFactory();
        TargetSource ts = new TargetSource() {
            @Override
            public Class<?> getTargetClass() {
                return descriptor.getDependencyType();
            }

            @Override
            public boolean isStatic() {
                return false;
            }

            @Override
            public Object getTarget() {
                return beanFactory.doResolveDependency(descriptor, beanName, null, null);
            }

            @Override
            public void releaseTarget(Object target) {
            }
        };
        ProxyFactory pf = new ProxyFactory();
        pf.setTargetSource(ts);
        Class<?> dependencyType = descriptor.getDependencyType();
        if (dependencyType.isInterface()) {
            pf.addInterface(dependencyType);
        }
        return pf.getProxy(beanFactory.getBeanClassLoader());
    }

}