Spring中基于Java的配置@Configuration和@Bean用法

Spring中为了减少xml中配置，可以创建一个配置类（例如ExampleConfiguration）来对bean进行配置。
1、配置spring配置文件来启用Java注解

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
	xmlns:batch="http://www.springframework.org/schema/batch"
	xmlns:context="http://www.springframework.org/schema/context"
	xmlns:jdbc="http://www.springframework.org/schema/jdbc"
	xsi:schemaLocation="
	 http://www.springframework.org/schema/batch http://www.springframework.org/schema/batch/spring-batch-2.1.xsd
	 http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-3.0.xsd
	 http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
	 http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd">

	<context:component-scan base-package="com.shanhy.demo" />

</beans>

2、定义一个配置类

@Configuration
public class ExampleConfiguration {

	@Value("${batch.jdbc.driver}")
	private String driverClassName;

	@Value("${batch.jdbc.url}")
	private String driverUrl;

	@Value("${batch.jdbc.user}")
	private String driverUsername;

	@Value("${batch.jdbc.password}")
	private String driverPassword;

	@Bean(name = "dataSource")
	public DataSource dataSource() {
		BasicDataSource dataSource = new BasicDataSource();
		dataSource.setDriverClassName(driverClassName);
		dataSource.setUrl(driverUrl);
		dataSource.setUsername(driverUsername);
		dataSource.setPassword(driverPassword);
		return dataSource;
	}

	@Bean
	public PlatformTransactionManager transactionManager() {
		return new DataSourceTransactionManager(dataSource());
	}

}

3、说明
用@Configuration注解的类，等价 与XML中配置beans；用@Bean标注方法等价于XML中配置的bean。