Spring @Profile注解详解

package com.spring.config;
 
import java.beans.PropertyVetoException;
 
import javax.sql.DataSource;
 
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.EmbeddedValueResolverAware;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Profile;
import org.springframework.context.annotation.PropertySource;
import org.springframework.util.StringValueResolver;
 
import com.mchange.v2.c3p0.ComboPooledDataSource;
 
/**
 * Profile:
 * 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；
 * 
 * 开发环境develop、测试环境test、生产环境master
 * 数据源：(/dev) (/test) (/master)
 *
 * @Profile: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，任何环境下都能注册这个组件
 * 
 * 1) 加了环境标识的bean，只有这个环境被激活的时候才能注册到容器中。默认是default环境
 * 2) 写在配置类上，只有是指定的环境的时候，整个配置类里面的所有配置才能开始生效
 * 
 */
@PropertySource("classpath:/dbconfig.properties")
@Configuration
public class MainConfigOfProfile implements EmbeddedValueResolverAware{
 
 @Value("${db.user}")
 private String user;
 
 private String driverClass;
 
 @Profile("default")
 @Bean("test")
 public DataSource testDataSource(@Value("${db.password}")String password) throws PropertyVetoException {
 ComboPooledDataSource dataSource = new ComboPooledDataSource();
 dataSource.setUser(user);
 dataSource.setPassword(password);
 dataSource.setDriverClass(driverClass);
 return dataSource;
 }
 
 @Profile("dev")
 @Bean("dev")
 public DataSource devDataSource(@Value("${db.password}")String password) throws PropertyVetoException {
 ComboPooledDataSource dataSource = new ComboPooledDataSource();
 dataSource.setUser(user);
 dataSource.setPassword(password);
 dataSource.setDriverClass(driverClass);
 return dataSource;
 }
 
 @Profile("master")
 @Bean("master")
 public DataSource masterDataSource(@Value("${db.password}")String password) throws PropertyVetoException {
 ComboPooledDataSource dataSource = new ComboPooledDataSource();
 dataSource.setUser(user);
 dataSource.setPassword(password);
 dataSource.setDriverClass(driverClass);
 return dataSource;
 }
 
 public void setEmbeddedValueResolver(StringValueResolver resolver) {
 String driverClass = resolver.resolveStringValue("${db.driverClass}");
 this.driverClass = driverClass;
 }
 
}

package com.spring.test;
 
import java.util.Arrays;
 
import javax.sql.DataSource;
 
import org.junit.Test;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
 
import com.spring.config.MainConfigOfProfile;
 
 
public class IOCTestProfile {
 //1. 使用命令行动态参数：在虚拟机参数位置加载 -Dspring.profiles.active=test
 //2. 使用代码的方式激活某种环境；
 @Test
 public void test01() {
 AnnotationConfigApplicationContext applicationContext = new AnnotationConfigApplicationContext(MainConfigOfProfile.class);
 //1. 创建一个applicationContext
 //2. 设置需要激活的环境
 applicationContext.getEnvironment().setActiveProfiles("dev","master");
 //3. 注册主配置类
 applicationContext.register(MainConfigOfProfile.class);
 //4. 启动刷新容器
 applicationContext.refresh();
 
 String[] beanNamesForType = applicationContext.getBeanNamesForType(DataSource.class);
 System.out.println(Arrays.toString(beanNamesForType));
 
 applicationContext.close();
 }
 
 
  @Test
 public void test02() {
 AnnotationConfigApplicationContext applicationContext = new AnnotationConfigApplicationContext(MainConfigOfProfile.class);
 
 String[] beanNamesForType = applicationContext.getBeanNamesForType(DataSource.class);
 System.out.println(Arrays.toString(beanNamesForType));
 
 applicationContext.close();
 }
}