HelloWorld 程序实现

加入依赖

此处同第一步骤 当前阶段只需要加入 Java Web的依赖即可.
pom.xml代码如下(idea 自动生成)

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.2.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.tcpgnl</groupId>
    <artifactId>helloworld</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>helloworld</name>
    <description>HelloWorld project for Spring Boot</description>

    <properties>
        <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>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>

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

</project>

````

## 第二步 编写controller
新建 HelloController.java 文件
加入注解(Spring 特性)
注解解释:
@GetMapping("/hello") 是将HTTP GET 方法映射到方法上(映射到后面的方法上)
HelloController.java代码如下:

```java
package com.tcpgnl.helloworld;

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

// 加入注解
@RestController
public class HelloController {
    @GetMapping("/hello")
    public String hello(){
        return "Hello World TCPGNL!";

    }

}

运行程序:

效果