org.springframework.batch.core.configuration.annotation.SimpleBatchConfiguration Maven / Gradle / Ivy
/*
* Copyright 2012-2013 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
*
* https://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.springframework.batch.core.configuration.annotation;
import java.util.concurrent.atomic.AtomicReference;
import org.aopalliance.intercept.MethodInterceptor;
import org.aopalliance.intercept.MethodInvocation;
import org.springframework.aop.framework.ProxyFactory;
import org.springframework.aop.target.AbstractLazyCreationTargetSource;
import org.springframework.batch.core.configuration.JobRegistry;
import org.springframework.batch.core.configuration.support.MapJobRegistry;
import org.springframework.batch.core.explore.JobExplorer;
import org.springframework.batch.core.launch.JobLauncher;
import org.springframework.batch.core.repository.JobRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.transaction.PlatformTransactionManager;
/**
* Base {@code Configuration} class providing common structure for enabling and using Spring Batch. Customization is
* available by implementing the {@link BatchConfigurer} interface. The main components are created as lazy proxies that
* only initialize when a method is called. This is to prevent (as much as possible) configuration cycles from
* developing when these components are needed in a configuration resource that itself provides a
* {@link BatchConfigurer}.
*
* @author Dave Syer
* @since 2.2
* @see EnableBatchProcessing
*/
@Configuration(proxyBeanMethods = false)
public class SimpleBatchConfiguration extends AbstractBatchConfiguration {
@Autowired
private ApplicationContext context;
private boolean initialized = false;
private AtomicReference jobRepository = new AtomicReference<>();
private AtomicReference jobLauncher = new AtomicReference<>();
private AtomicReference jobRegistry = new AtomicReference<>();
private AtomicReference transactionManager = new AtomicReference<>();
private AtomicReference jobExplorer = new AtomicReference<>();
@Override
@Bean
public JobRepository jobRepository() throws Exception {
return createLazyProxy(jobRepository, JobRepository.class);
}
@Override
@Bean
public JobLauncher jobLauncher() throws Exception {
return createLazyProxy(jobLauncher, JobLauncher.class);
}
@Override
@Bean
public JobRegistry jobRegistry() throws Exception {
return createLazyProxy(jobRegistry, JobRegistry.class);
}
@Override
@Bean
public JobExplorer jobExplorer() {
return createLazyProxy(jobExplorer, JobExplorer.class);
}
@Override
@Bean
public PlatformTransactionManager transactionManager() throws Exception {
return createLazyProxy(transactionManager, PlatformTransactionManager.class);
}
private T createLazyProxy(AtomicReference reference, Class type) {
ProxyFactory factory = new ProxyFactory();
factory.setTargetSource(new ReferenceTargetSource<>(reference));
factory.addAdvice(new PassthruAdvice());
factory.setInterfaces(new Class[] { type });
@SuppressWarnings("unchecked")
T proxy = (T) factory.getProxy();
return proxy;
}
/**
* Sets up the basic components by extracting them from the {@link BatchConfigurer configurer}, defaulting to some
* sensible values as long as a unique DataSource is available.
*
* @throws Exception if there is a problem in the configurer
*/
protected void initialize() throws Exception {
if (initialized) {
return;
}
BatchConfigurer configurer = getConfigurer(context.getBeansOfType(BatchConfigurer.class).values());
jobRepository.set(configurer.getJobRepository());
jobLauncher.set(configurer.getJobLauncher());
transactionManager.set(configurer.getTransactionManager());
jobRegistry.set(new MapJobRegistry());
jobExplorer.set(configurer.getJobExplorer());
initialized = true;
}
private class PassthruAdvice implements MethodInterceptor {
@Override
public Object invoke(MethodInvocation invocation) throws Throwable {
return invocation.proceed();
}
}
private class ReferenceTargetSource extends AbstractLazyCreationTargetSource {
private AtomicReference reference;
public ReferenceTargetSource(AtomicReference reference) {
this.reference = reference;
}
@Override
protected Object createObject() throws Exception {
initialize();
return reference.get();
}
}
}