一、註解方式

編寫實體類：

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註解為自動裝載，註解ConfigurationProperties的prefix = “hello”可以在application.yml或application.properties中進行賦值，如：hello.msg = Loser100。若不賦值則預設為”hello”!

二、配置檔案方式
編寫實體:
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檔案，內容為：

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

三、使用
使用時直接使用@Autowired標籤即可，如：

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

附上學習工程截圖：