@Profile注解
Spring为我们提供的可以根据当前环境，动态的激活和切换一系列组件的功能。指定组件在哪个环境的情况下才能被注册到容器中，不指定则任何环境下都能注册这个组件。
可以通过如下四种方式指定Bean生效的环境。
ConfigurableEnvironment.setActiveProfiles AbstractEnvironment.ACTIVE_PROFILES_PROPERTY_NAME =spring.profiles.active web.xml配置 @ActiveProfiles注解
接口类如下：
@Target({ElementType.TYPE, ElementType.METHOD}) @Retention(RetentionPolicy.RUNTIME) @Documented @Conditional(ProfileCondition.class) public @interface Profile { /** * The set of profiles for which the annotated component should be registered. */ String[] value(); }
① 如果不加@Profile注解，则该bean在任何环境下都被注入
@Bean public Yellow yellow(){ return new Yellow(); }
② 如果指定了@Profile，则只有该环境被激活的时候bean才会被注入
@Profile("dev") @Bean("devDataSource") public DataSource dataSourceDev(@Value("${db.password}")String pwd) throws Exception{ ComboPooledDataSource dataSource = new ComboPooledDataSource(); dataSource.setUser(user); dataSource.setPassword(pwd); dataSource.setJdbcUrl("jdbc:mysql://localhost:3306/xian"); dataSource.setDriverClass(driverClass); return dataSource; }
③ 如果指定了@Profile(“default”)，那么默认环境下bean会被注入
@Profile("default") @Bean("testDataSource") public DataSource dataSourceTest(@Value("${db.password}")String pwd) throws Exception{ ComboPooledDataSource dataSource = new ComboPooledDataSource(); dataSource.setUser(user); dataSource.setPassword(pwd); dataSource.setJdbcUrl("jdbc:mysql://localhost:3306/test"); dataSource.setDriverClass(driverClass); return dataSource; }
④ 如果@Profile配置于类上，则该类下的bean想起作用，Spring激活的环境首先要与类配置@Profile指定的环境一致，其次再看类中方法上的@Profile注解配置。
@PropertySource("classpath:/dbconfig.properties") @Profile("dev") @Configuration public class MainConfigOfProfile implements EmbeddedValueResolverAware{ @Value("${db.user}") private String user; private StringValueResolver valueResolver; private String driverClass; @Bean public Yellow yellow(){ return new Yellow(); } @Profile("default") // @Profile("test") @Bean("testDataSource") public DataSource dataSourceTest(@Value("${db.password}")String pwd) throws Exception{ ComboPooledDataSource dataSource = new ComboPooledDataSource(); dataSource.setUser(user); dataSource.setPassword(pwd); dataSource.setJdbcUrl("jdbc:mysql://localhost:3306/test"); dataSource.setDriverClass(driverClass); return dataSource; } @Profile("dev") @Bean("devDataSource") public DataSource dataSourceDev(@Value("${db.password}")String pwd) throws Exception{ ComboPooledDataSource dataSource = new ComboPooledDataSource(); dataSource.setUser(user); dataSource.setPassword(pwd); dataSource.setJdbcUrl("jdbc:mysql://localhost:3306/xian"); dataSource.setDriverClass(driverClass); return dataSource; } }
激活环境的几种方式
① 虚拟机参数
② 代码激活
@Test public void test01(){ //1、创建一个applicationContext AnnotationConfigApplicationContext applicationContext = new AnnotationConfigApplicationContext(); //2、设置需要激活的环境 applicationContext.getEnvironment().setActiveProfiles("dev"); //3、注册主配置类 applicationContext.register(MainConfigOfProfile.class); //4、启动刷新容器 applicationContext.refresh(); String[] namesForType = applicationContext.getBeanNamesForType(DataSource.class); for (String string : namesForType) { System.out.println(string); } Yellow bean = applicationContext.getBean(Yellow.class); System.out.println(bean); applicationContext.close(); }
③ web.xml
<!-- 在上下文中设置profile的默认值 --> <context-param> <param-name>spring.profiles.default</param-name> <param-value>dev</param-value> </context-param> <servlet> <servlet-name>appServlet</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <!-- 在servlet中设置profile的默认值 --> <init-param> <param-name>spring.profiles.default</param-name> <param-value>dev</param-value> </init-param> <load-on-startup>1</load-on-startup> </servlet>
