01. Hello World!

一、环境准备

        1、JDK1.8

        2、开发工具STS3.8.4

        3、项目管理工具Maven3.5.0

二、新建MAVEN项目

三、编辑pom.xml文件

1、新增parent标签

1. <parent>
2. <groupId>org.springframework.boot</groupId>
3. <artifactId>spring-boot-starter-parent</artifactId>
4. <version>1.5.3.RELEASE</version>
5. </parent>

2、新增jdk版本约束

1. <properties>
2. <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
3. <java.version>1.8</java.version>
4. </properties>

3、新增spring-boot-starter-web依赖

1. <dependencies>
2. <dependency>
3. <groupId>org.springframework.boot</groupId>
4. <artifactId>spring-boot-starter-web</artifactId>
5. </dependency>
6. </dependencies>

4、完整pom.xml文件

1. <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
2. xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
3. <modelVersion>4.0.0</modelVersion>
5. <groupId>org.goldwind</groupId>
6. <artifactId>01HelloWorld</artifactId>
7. <version>0.0.1-SNAPSHOT</version>
8. <packaging>jar</packaging>
10. <name>01HelloWorld</name>
11. <url>http://maven.apache.org</url>
13. <parent>
14. <groupId>org.springframework.boot</groupId>
15. <artifactId>spring-boot-starter-parent</artifactId>
16. <version>1.5.3.RELEASE</version>
17. </parent>
19. <properties>
20. <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
21. <java.version>1.8</java.version>
22. </properties>
24. <dependencies>
25. <dependency>
26. <groupId>org.springframework.boot</groupId>
27. <artifactId>spring-boot-starter-web</artifactId>
28. </dependency>
29. <dependency>
30. <groupId>junit</groupId>
31. <artifactId>junit</artifactId>
32. <scope>test</scope>
33. </dependency>
34. </dependencies>
35. </project>

四、编写Controller

1. package org.goldwind;
3. import org.springframework.web.bind.annotation.RequestMapping;
4. import org.springframework.web.bind.annotation.RestController;
6. @RestController
7. public class HelloWorldController {
9. @RequestMapping("/hello")
10. public String hello(){
11. return "Hello World!";
12. }
13. }

五、编写App.java

1. package org.goldwind;
3. import org.springframework.boot.SpringApplication;
4. import org.springframework.boot.autoconfigure.SpringBootApplication;
6. /**
7. * Hello world!
8. *
9. */
10. @SpringBootApplication
11. public class App
12. {
13. public static void main( String[] args )
14. {
15. System.out.println( "Hello World!" );
16. SpringApplication.run(App.class, args);
17. }
18. }

六、启动项目

以启动java工程的方式启动App.java中的main函数

访问路径：http://localhost:8080/hello

注意，如果MAVEN项目报错，请按如下方式解决：
Alt+F5——勾选当前项目（默认已经勾选）——OK