idea创建springboot项目

首先配置jdk和maven   在这里就不说了自己在网搜一大片

下面直接代码和图     有图有真相

 

 

项目结构为：

项目默认的 maven pom.xml文件

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>

<groupId>com.jxust</groupId>
<artifactId>spirngbootdemo</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>

<name>spirngbootdemo</name>
<description>Demo project for Spring Boot</description>

<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.4.2.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>

<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
</properties>

<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>

<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>

<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>

运行SpirngbootdemoApplication的main方法，就能开始运行。

其他启动方式，请看视频教程http://www.imooc.com/learn/767

控制台输出：

"C:Program FilesJavajdk1.8.0_91injava" ....

. ____ _ __ _ _
/\ / ___'_ __ _ _(_)_ __ __ _
( ( )\___ | '_ | '_| | '_ / _` |
\/ ___)| |_)| | | | | || (_| | ) ) ) )
' |____| .__|_| |_|_| |_\__, | / / / /
=========|_|==============|___/=/_/_/_/
:: Spring Boot :: (v1.4.2.RELEASE)
2016-12-16 14:56:52.083 INFO 15872 --- [ main] o.s.j.e.a.AnnotationMBeanExporter : Registering beans for JMX exposure on startup
2016-12-16 14:56:52.215 INFO 15872 --- [ main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat started on port(s): 8080 (http)
2016-12-16 14:56:52.255 INFO 15872 --- [ main] com.jxust.SpirngbootdemoApplication : Started SpirngbootdemoApplication in 7.795 seconds (JVM running for 9.177)

创建一个HelloController，位于controller包下

HelloController.java

package com.jxust.controller;

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

/**
* Created by Peng
* Time: 2016/12/16 15:45
*/
@RestController
public class HelloController {

@RequestMapping("/hello")
public String say(){
return "Hello SpringBoot!";
}
}

@RestController Spring4 之后新加的注解,原来返回json需要@ResponseBody配合@Controller,现在一个顶俩

在浏览器中输入http://localhost:8080/hello就能输出Hello SpringBoot!这句话。

自定义属性配置

用到的是application.properties这个文件

配置端口号和访问前缀

application.properties

server.port=8081
server.context-path=/springboot

除了使用.properties格式的文件，还可以使用.yml格式的配置文件(推荐)，更加简便
application.yml

把原来的application.properties文件删除
注意格式，空格不能少

获取配置文件中的属性值
我们也可以在配置文件中，配置数据，在 Controller 中获取,比如：
application.yml

server:
port: 8081
context-path: /springboot
name: 小胖

HelloController 获取配置文件中的值

HelloController.java

....
@RestController
public class HelloController {

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

@RequestMapping(value = "/hello",method = RequestMethod.GET)
public String say(){
return name;
}
}

配置文件中值配置方式的多样化
配置文件的值可以是多个，也可以是组合，如：

application.yml
name: 小胖
age: 22
1
2
或者

application.yml
name: 小胖
age: 22
content: "name: ${name},age: ${age}"
1
2
3
或者

application.yml
server:
port: 8081
context-path: /springboot
person:
name: 小胖
age: 22

前两种配置获取值的方式都是一样的,但是对于这种方式，person 有相应的两个属性，需要这样处理

PersonProperties.java

package com.jxust;

import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;

/**
* Created by Peng
* Time: 2016/12/16 16:34
*/
@Component
@ConfigurationProperties(prefix = "person")
public class PersonProperties {
private String name;
private Integer age;

public String getName() {
return name;
}

public void setName(String name) {
this.name = name;
}

public Integer getAge() {
return age;
}

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


Alt+insert快捷键提示生成 Getter and Setter

pom.xml需要加入下面的依赖,处理警告

<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-configuration-processor</artifactId>
<optional>true</optional>
</dependency>

HelloController.java

package com.jxust.controller;

import com.jxust.PersonProperties;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

/**
* Created by Peng
* Time: 2016/12/15 20:55
*/
@RestController
public class HelloController {

@Autowired
private PersonProperties personProperties;

@RequestMapping(value = "/hello",method = RequestMethod.GET)
public String say(){
return personProperties.getName()+personProperties.getAge();
}
}

 

关于配置文件application.yml的多套配置

由application.yml配置文件决定使用那套配置文件。

application.yml

spring:
profiles:
active: a

application-a.yml

server:
port: 8081
context-path: /springboot
person:
name: 小雷
age: 21

application-b.yml

server:
port: 8081
context-path: /springboot
person:
name: 小胖
age: 22

转自https://blog.csdn.net/peng_hong_fu/article/details/53691705