Java Bean定义不是从Spring ApplationConext.xml文件加载的

有了@Qualifier("queries")，我就能够"连接"所描述的(XML+)映射……如下所示:

package com.example.demo;

import java.util.Map;

import org.springframework.beans.factory.InitializingBean;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ImportResource;

@SpringBootApplication
@ImportResource("classpath:applicationContext.xml")
public class Demo {
    public static void main(String[] args) {
        SpringApplication.run(Demo.class, args);
    }

    @Bean
    InitializingBean hello(/*@Autowired*/ @Qualifier("queries") Map<String, String> queries) {
        return () -> System.err.println(queries);
    }
}

...没有强有力的论据，为什么它不应该在任何Bean/存储库/服务中工作.

不过，我不能这么快地重现这个错误:省略限定符至少会填充(以某种方式在默认的快速入门中)empty map .

要重现"失败的应用程序启动"，我们可以使用:

@Bean
InitializingBean hello2(Map x) {
  return () -> System.err.println(x);
}

，其中或:

• (参数)名称符合条件
• (Nor)声明的泛型类型参数.

它为我们提供了(在弹簧靴快速启动中):

...
***************************
APPLICATION FAILED TO START
***************************

Description:

Parameter 0 of method hello2 in com.example.demo.Demo required a single bean, but 5 were found:
        - queries: defined in unknown location
        - systemProperties: a programmatically registered singleton
        - systemEnvironment: a programmatically registered singleton
        - contextParameters: a programmatically registered singleton
        - contextAttributes: a programmatically registered singleton

@Value替代方案

这也是可能的:

//..somewhere in a spring bean (aware of applicationContext.xml)...
@Value("#{queries}") Map<String, String> queries;

...一个(org.springframework...)@Value + SpEL的"'查询' bean"+匹配字段/参数.