Had I not seen the Sun[我本可以忍受黑暗]
I could have borne the shade[如果我不曾见过太阳]
But Light a newer Wilderness[然而阳光已使我的荒凉]
My Wilderness has made[成为更新的荒凉]
——Emily Dickinson
之前我们引用spring里的bean都是通过@Autowired或者@Resource注解获取
这里可以使用第三种方式
首先写个工具类
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| package com.ruben.utils;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.DisposableBean;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Lazy;
import org.springframework.stereotype.Component;
import org.springframework.stereotype.Service;
import java.util.Optional;
@Lazy(false)
@Component("SpringContextHolder")
public class SpringContextHolder implements ApplicationContextAware, DisposableBean {
private static ApplicationContext applicationContext;
private static final String ERROR_MESSAGE = "applicationContext尚未注入";
@Override
public void destroy() {
applicationContext = null;
}
@Override
public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
SpringContextHolder.applicationContext = applicationContext;
}
public static <T> T getBean(Class<T> type) {
return Optional.ofNullable(applicationContext).orElseThrow(() -> new IllegalStateException(ERROR_MESSAGE)).getBean(type);
}
@SuppressWarnings("unchecked")
public static <T> T getBean(String name) {
return (T) Optional.ofNullable(applicationContext).orElseThrow(() -> new IllegalStateException(ERROR_MESSAGE)).getBean(name);
}
}
|
然后就可以通过
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| private static final UserService userService = SpringContextHolder.getBean(UserService.class);
|
获取到注入到spring容器的bean
注意，如果是单体架构项目需要在引用时在对应的组件上加@DependsOn("SpringContextHolder")注解
或者是分布式项目的话，直接写到最顶层依赖部分就行