springboot实现bean手动注入

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本文介绍了一个Spring Boot应用如何通过实现ApplicationListener<ContextRefreshedEvent>接口来监听上下文初始化事件，并展示了如何使用自定义工具类SpringContextUtil获取ApplicationContext及Bean实例。

1.springboot启动类实现接口ApplicationListener<ContextRefreshedEvent>，实现方法onApplicationEvent，初始化上下文

package test.projectTest;

import org.mybatis.spring.boot.autoconfigure.MybatisAutoConfiguration;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;
import org.springframework.boot.autoconfigure.jdbc.DataSourceTransactionManagerAutoConfiguration;
import org.springframework.boot.system.ApplicationPidFileWriter;
import org.springframework.context.ApplicationListener;
import org.springframework.context.event.ContextRefreshedEvent;

import test.projectTest.util.SpringContextUtil;

@EnableAutoConfiguration(exclude = {DataSourceAutoConfiguration.class,DataSourceTransactionManagerAutoConfiguration.class, MybatisAutoConfiguration.class})
@SpringBootApplication(scanBasePackages={"test.projectTest"})
public class TestApplication implements ApplicationListener<ContextRefreshedEvent>
{
public static void main( String[] args )
{
   SpringApplication application = new SpringApplication(TestApplication.class);
   application.addListeners(new ApplicationPidFileWriter());
   application.run(args);
System.out.println( "启动成功" );
}

   @Override
   public void onApplicationEvent(ContextRefreshedEvent event) {
       SpringContextUtil.setApplicationContext(event.getApplicationContext());

   }
}

2.SpringContextUtil工具类初始化ApplicationContext applicationContext

package test.projectTest.util;

import org.springframework.context.ApplicationContext;
/**
* 获取spring容器，以访问容器中定义的其他bean
*/
public class SpringContextUtil{
   //spring上下文
   private static ApplicationContext applicationContext;

   /**
   * 实现ApplicationContextAware接口的回调方法，设置上下文环境
   * @param applicationContext
   */
   public static void setApplicationContext(ApplicationContext applicationContext){
       if(null==SpringContextUtil.applicationContext)
           SpringContextUtil.applicationContext=applicationContext;
   }

   public static ApplicationContext getApplicationContext(){
       return applicationContext;
   }
   /**
* 通过name获取 Bean.
*
* @param name
* @return
*/
public static Object getBean(String name) {
return getApplicationContext().getBean(name);

}

/**
* 通过name获取 Bean.
*
* @param clazz
* @return
*/
public static <T> T getBean(Class<T> clazz) {
return getApplicationContext().getBean(clazz);
}

/**
* 通过name,以及Clazz返回指定的Bean
*
* @param name
* @param clazz
* @return
*/
public static <T> T getBean(String name, Class<T> clazz) {
return getApplicationContext().getBean(name, clazz);
}

}

3.获取bean

package test.projectTest.util;

import test.projectTest.mapper.slave.DailyDataMapper;

public class TestUtil{

   private static DailyDataMapper dailyDataMapper;

   static{//手动注入bean
       if(dailyDataMapper==null){
           dailyDataMapper = (DailyDataMapper)SpringContextUtil.getBean("dailyDataMapper");

       }
   }
   public static void test(){
       dailyDataMapper.selectByPrimaryKey(1);
   }


}