图解如何用IDEA创建Spring boot项目

创建项目并启动

新建ShowtimeController类，内容如下

package com.showtime.showtime;

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

/**
 * 描述:用于Spring Boot学习
 *
 * @author jianyiwei
 * @create 2018-04-22 3:35 PM
 */

@RestController
public class ShowtimeController {

    @RequestMapping(value = "/")
    public String say(){
        return "Hello Spring Boot!";
    }
}

运行ShowtimeApplication中的main方法，启动项目

package com.showtime.showtime;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class ShowtimeApplication {

    public static void main(String[] args) {
        SpringApplication.run(ShowtimeApplication.class, args);
    }
}

通过浏览器访问

属性文件配置

application.properties配置文件中加入如下内容：

# 服务端口
server.port=9080

# 访问路径
server.servlet.context-path=/showtime

此时在浏览器访问：

application.properties配置文件格式可以改为application.yml，此时内容如下：

server:
  port: 9080 # 服务端口
  servlet:
    context-path: /showtime

配置自定义变量

在application.yml中加入自定义变量：

username: jianyiwei

age: 27

ShowtimeController修改为：

@RestController
public class ShowtimeController {

    @Value("${username}")
    private String username;

    @Value("${age}")
    private String age;

    @RequestMapping(value = "/")
    public String say(){
        return "Hello Spring Boot! I am "+username+" I am "+age+"years old";
    }
}

浏览器访问：

自定义变量里引用自定义变量

username: jianyiwei

age: 27

content: "username: ${username}, age: ${age}"

代码修改：

@RestController
public class ShowtimeController {

    @Value("${content}")
    private String content;

    @RequestMapping(value = "/")
    public String say(){
        return content;
    }
}

配置分组

showtime:
  username: jianyiwei
  age: 27

新建ShowtimeProperties

// 注入配置
@Component
@ConfigurationProperties(prefix = "showtime")
public class ShowtimeProperties {

    private String username;

    private Integer age;

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }
}

ShowtimeController修改为:

@RestController
public class ShowtimeController {

    @Autowired
    private ShowtimeProperties showtimeProperties;

    @RequestMapping(value = "/")
    public String say(){
        return showtimeProperties.getUsername()+"  "+showtimeProperties.getAge();
    }
}