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: 
SpringBoot配置Bean的两种方式--注解以及配置文件
原文:https://www.cnblogs.com/jpfss/p/9066522.html