HelloWorld 程序实现

<?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: ```javapackage com.tcpgnl.helloworld; import org.springframework.web.bind.annotation.GetMapping;import org.springframework.web.bind.annotation.RestController; // 加入注解@RestControllerpublic class HelloController {    @GetMapping("/hello")    public String hello(){        return "Hello World TCPGNL!";     } }