1. Spring Boot简介

关于Spring Boot介绍，引用官网的一段话如下：

Spring Boot makes it easy to create stand-alone, production-grade Spring based Applications that you can “just run”. We take an opinionated view of the Spring platform and third-party libraries so you can get started with minimum fuss. Most Spring Boot applications need very little Spring configuration.

You can use Spring Boot to create Java applications that can be started using java -jar or more traditional war deployments. We also provide a command line tool that runs “spring scripts”.

Our primary goals are:

Provide a radically faster and widely accessible getting started experience for all Spring development.Be opinionated out of the box, but get out of the way quickly as requirements start to diverge from the defaults.Provide a range of non-functional features that are common to large classes of projects (e.g. embedded servers, security, metrics, health checks, externalized configuration).Absolutely no code generation and no requirement for XML configuration. Spring Boot的宗旨是简化Spring 应用的开发，只需要使用极少的Spring 配置就能将项目运行起来。相对于传统Spring项目，Spring Boot去除了繁杂的xml文件配置而采用注解替代。 在运行方式上，既可以采用 java -jar直接运行，也可以用传统war包的方式来部署，当然还可以通过Spring 脚本来部署。

2. Spring Boot 简单例子

2.1 创建一个maven项目

创建一个maven项目，结构如下：

2.2 pom.xml配置

<?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.gallenzhang</groupId> <artifactId>springboot-demo</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>jar</packaging> <name>springboot-demo</name> <description>A simple demo of Spring Boot</description> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>1.4.0.RELEASE</version> <relativePath /> </parent> <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>

2.3 Controller代码

package com.gallenzhang.controller; import java.util.HashMap; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestParam; import org.springframework.web.bind.annotation.RestController; @RestController @RequestMapping(value = "/hello") public class HelloController { @RequestMapping public String index(){ return "This is a simple demo of spring boot."; } @RequestMapping(value = "/get") public HashMap<String, Object> get(@RequestParam String name){ HashMap<String,Object> map = new HashMap<String, Object>(); map.put("msg", "hello " + name); return map; } }

2.4 启动类

package com.gallenzhang; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; @SpringBootApplication public class SpringBootDemoApplication { public static void main(String[] args) { SpringApplication.run(SpringBootDemoApplication.class, args); } }

3. 启动

启动的方式非常简单，直接右键运行SpringBootDemoApplication 类即可。

4. 测试

浏览器访问   http://localhost:8080/hello , 可以看到页面输出： This is a simple demo of spring boot. http://localhost:8080/hello/get?name=zhangsan , 页面输出：   {"msg":"hello zhangsan"}