我正在学习 Spring Boot 。我试图通过点击http：//localhost：8080 url从控制器获得响应。但不幸的是我没有得到预期的响应。
这是我的控制器...

package com.learning.helloworld;

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

@RestController
public class ProductController {
    @GetMapping
    public String product(){
        System.out.println("Hi");
        return "the product is sold";
    }
}

下面是pom.xml

<?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>3.0.3</version>
    <relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.learning</groupId>
<artifactId>helloworld</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>helloworld</name>
<description>Demo project for Spring Boot</description>
<properties>
    <java.version>19</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>
    </dependency>
</dependencies>

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

点击http：//localhost：8080 URL后，浏览器显示

如何解决这个问题？