SpringBoot入门：Hello World(一)

跟随SpringBoot的文档（http://docs.spring.io/spring-boot/docs/current-SNAPSHOT/reference/htmlsingle/#boot-documentation）学习，前后几章关联才调通代码，煞是痛苦，在这里记录结果，过程隐忍。

一、准备工作

1、根据Maven工程特点，建立文档结果

myFirstProject

+-src

+-main

+-java

+-resources

+-test

+-java

+-resources

2、再在src/main/java下依次建立文件夹com，example，myFirstProject，可以构成Maven工程包(package)–>com.example.myFirstProject,最后文档结构如图1



图1

3、编制pom.xml,存于myFirstProject文件夹下，与src同级

<?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.example</groupId>
<artifactId>myFirstproject</artifactId>
<version>0.0.1-SNAPSHOT</version>

<!-- Inherit defaults from Spring Boot -->
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.4.0.BUILD-SNAPSHOT</version>
</parent>

<!-- Add typical dependencies for a web application -->
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
</dependencies>

<!-- Package as an executable jar -->
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>

<!-- Add Spring repositories -->
<!-- (you don't need this if you are using a .RELEASE version) -->
<repositories>
<repository>
<id>spring-snapshots</id>
<url>http://repo.spring.io/snapshot</url>
<snapshots><enabled>true</enabled></snapshots>
</repository>
<repository>
<id>spring-milestones</id>
<url>http://repo.spring.io/milestone</url>
</repository>
</repositories>
<pluginRepositories>
<pluginRepository>
<id>spring-snapshots</id>
<url>http://repo.spring.io/snapshot</url>
</pluginRepository>
<pluginRepository>
<id>spring-milestones</id>
<url>http://repo.spring.io/milestone</url>
</pluginRepository>
</pluginRepositories>
</project>

文档内容从SpringBoot的文档拷贝

4、编制Application.java存于myFirstProject\src\main\java\com\example\myFirstProject下

package com.example.myFirstProject;

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

@SpringBootApplication
public class Application {

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

5、编制Example.java，存于myFirstProject\src\main\java\com\example\myFirstProject下

package com.example.myFirstProject;

import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@EnableAutoConfiguration
public class Example {

@RequestMapping("/")
String home() {
return "Hello World!";
}

@RequestMapping("/hello/{myName}")
String index(@PathVariable String myName) {
return "Hello "+myName+"!!!";
}
}

二、Maven工程导入

1、启动eclipse

1.1、java–>jdk1.7.0_80x64

1.2、maven–>Apache Maven 3.3.3

1.3、Eclipse Java EE IDE for Web Developers. Version: Mars Release (4.5.0)

1.4、为本练习，新建一个workgroup

2、在eclipse中，依次点击file–>import–>Maven–>Existing Maven Projects–>Next–>Browse–>定位到myFirstProject文件夹–>确定–Finish

3、导入结果如图2



图2

三、运行

1、在eclipse的工程myFirstProject上右击鼠标，选择Run as–>Java Application，如图3



2、在select Java Aplication中选择“Application -com.example.myFirstProject”，如图4



图4

3、再次点击“OK”按钮,在Eclipse的Console中开始打印如图5



图5

4、打开浏览器，输入http://localhost:8080，显示如图6



5、在浏览器中,输入http://localhost:8080/hello/SpringBoot



四、后记

痛则不通，通则不痛。这个例子非常之简单，为了这个简单，费事不少。为了这个例子能够成功，最好做以下准备

1、构建本地的Maven伺服，否则速度痛苦

2、Sonatype Nexus尽量和jdk相对应的版本，不要最求最新，否则可能启动不起来。

3、Sonatype Nexus搭建，参考