SpringBoot REST API访问返回404问题求助（附完整项目信息）

我此前从事Struts MVC SOAP项目开发，刚接触SpringBoot与REST API技术。目前编写了一个SpringBoot REST接口，但使用浏览器或curl工具访问时始终返回404错误。现将项目相关信息提供如下，烦请帮忙排查问题，并确认我提供的信息是否足够用于定位该问题：

• IntelliJ IDEA 2021.3.3（Community Edition）
• Build #IC-213.7172.25，构建于2022年3月15日
• Runtime版本：11.0.14.1+1-b1751.46 amd64
• VM：JetBrains s.r.o.的OpenJDK 64-Bit Server VM
• 操作系统：Windows 10 10.0
• GC：G1 Young Generation、G1 Old Generation
• 内存：1776M
• 核心数：8
• 非捆绑插件：org.jetbrains.kotlin(213-1.6.20-release-275-IJ6777.52)、dev.flikas.idea.spring.boot.assistant.plugin(0.2.4)
• Kotlin版本：213-1.6.20-release-275-IJ6777.52

<?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>2.6.6</version>
<relativePath/>
<!-- lookup parent from repository -->
</parent>
<groupId>com.restweek</groupId>
<artifactId>restweekend</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>restweekend</name>
<description>Demo project for Spring Boot Rest</description>
<properties>
<java.version>11</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>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.13.0</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.projectlombok/lombok -->
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.22</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>

3.1 Controller代码 #

package com.restweek.restweekend.controller;
import com.restweek.restweekend.elementi.Product;
import com.restweek.restweekend.services.implementazioni.RichiestaImpl;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;
import java.util.List;

@RestController
@RequestMapping("/radice")
public class ControllerProva {
@Autowired
private RichiestaImpl richiesta;

@GetMapping("/product")
public List<Product> getProduct() {
List<Product> products = richiesta.findAll();
return products;
}
}

3.2 Product实体类代码 #

package com.restweek.restweekend.elementi;
public class Product {
private int id;
private String pname;
private String batchno;
private double price;
private int noofproduct;

public Product() {
}

public Product(int id, String pname, String batchno, double price, int noofproduct) {
super();
this.id = id;
this.pname = pname;
this.batchno = batchno;
this.price = price;
this.noofproduct = noofproduct;
}

public int getId() {
return id;
}

public void setId(int id) {
this.id = id;
}

public String getPname() {
return pname;
}

public void setPname(String pname) {
this.pname = pname;
}

public String getBatchno() {
return batchno;
}

public void setBatchno(String batchno) {
this.batchno = batchno;
}

public double getPrice() {
return price;
}

public void setPrice(double price) {
this.price = price;
}

public int getNoofproduct() {
return noofproduct;
}

public void setNoofproduct(int noofproduct) {
this.noofproduct = noofproduct;
}
}

3.3 Richiesta接口代码 #

package com.restweek.restweekend.services.interfaccie;
import com.restweek.restweekend.elementi.Product;
import lombok.Data;
import org.springframework.stereotype.Service;
import java.util.List;

@Service
public interface Richiesta {
List<Product> findAll();
}

3.4 RichiestaImpl实现类代码 #

package com.restweek.restweekend.services.implementazioni;
import com.restweek.restweekend.elementi.Product;
import com.restweek.restweekend.services.interfaccie.Richiesta;
import org.springframework.stereotype.Service;
import java.util.ArrayList;
import java.util.List;

@Service
public class RichiestaImpl implements Richiesta {
@Override
public List<Product> findAll() {
ArrayList<Product> products = new ArrayList<Product>();
products.add(new Product(100, "Mobile", "CLK98123", 9000.00, 6));
products.add(new Product(101, "Smart TV", "LGST09167", 60000.00, 3));
products.add(new Product(102, "Washing Machine", "38753BK9", 9000.00, 7));
products.add(new Product(103, "Laptop", "LHP29OCP", 24000.00, 1));
products.add(new Product(104, "Air Conditioner", "ACLG66721", 30000.00, 5));
products.add(new Product(105, "Refrigerator ", "12WP9087", 10000.00, 4));
return products;
}
}

3.5 SpringBoot启动类代码 #

package com.restweek.restweekend.start;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

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

执行命令：

C:\Users\franc>curl http://localhost:8080/radice/product

返回结果：

{"timestamp":"2022-04-09T14:58:34.741+00:00","status":404,"error":"Not Found","path":"/radice/product"}

我帮你梳理几个可能导致404的关键点：

1. 启动类包扫描范围：你的启动类在com.restweek.restweekend.start包下，虽然默认@SpringBootApplication会扫描启动类所在包及其子包，但可以明确添加@ComponentScan(basePackages = "com.restweek.restweekend")确保所有组件被扫描到，试试这个操作。
2. 接口注解错误：Richiesta接口上标注了@Service注解，这是错误的！@Service应该只标注在实现类上，接口不需要这个注解，删掉接口上的@Service，避免Spring扫描逻辑混乱。
3. 依赖重复冲突：pom.xml里lombok依赖添加了两次，一次带scope=provided一次没有，建议只保留带provided的那一条，因为lombok是编译期注解，不需要打包到运行环境。
4. 端口验证：确认SpringBoot启动日志里显示的端口是8080吗？如果8080被占用，SpringBoot会自动切换端口，你可以查看启动日志中Tomcat started on port(s): xxx (http)这行信息。

你提供的信息已经非常全面了，包含开发环境、依赖配置、所有核心代码以及测试结果，完全足够定位这个404问题。

内容的提问来源于stack exchange，提问作者fragen1999