如何读取Spring boot application.properties 配置内容

有些同学可能需要从 application.properties 配置文件中读取自定义配置，可使用如下方法获取

配置文件内容

hello.world = hi spring boot!

java 代码如下

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.env.Environment;
import org.springframework.http.MediaType;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class SampleController {
    @Autowired
    private Environment environment;
    @RequestMapping(value = "/say", produces = MediaType.APPLICATION_JSON_UTF8_VALUE)
    public String say() {
        String msg = environment.getProperty("hello.world");
        return msg;
    }
}