SpringBoot配置Bean的两种方式--注解以及配置文件

约定不等于承诺〃 2022-06-07 03:47 430阅读 0赞

一、注解方式

编写实体类：

package com.example.bean;
    
    
    import org.springframework.boot.context.properties.ConfigurationProperties;
    
    /** * Created by Loser100 on 2017/10/9. */
    @Component
    @ConfigurationProperties(prefix = "hello")
    public class HelloServiceProperties { 
    
        private static final String MSG = "hello";
    
        private String msg = MSG;
    
        public String getMsg() {
            return msg;
        }
    
        public void setMsg(String msg) {
            this.msg = msg;
        }
    }

其中Component注解为自动装载，注解ConfigurationProperties的prefix = “hello”可以在application.yml或application.properties中进行赋值，如：hello.msg = Loser100。若不赋值则默认为”hello”!

二、配置文件方式  
编写实体:  
package com.example.services;

/\*\*  
\* Created by Loser100 on 2017/10/9.  
\*/  
public class HelloService \{

private String msg;
    
    public String sayHello(){
        return "HELLO" + msg;
    }
    
    public String getMsg() {
        return msg;
    }
    
    public void setMsg(String msg) {
        this.msg = msg;
    }

\}  
rce.META-INF下新建spring.factories文件，内容为：

org.springframework.boot.autoconfigure.EnableAutoConfiguration=main.java.com.example.services.HelloService

三、使用  
使用时直接使用@Autowired标签即可，如：

@Autowired
        private HelloService helloServiceProperties;
        String sayHello(){
           return helloServiceProperties.sayHello();
        }

附上学习工程截图：  
![工程截图][SouthEast]

[SouthEast]: /images/20220607/3bcb410743b54fb69516ccaaf73d341f.png