从部署在 Tomcat 上的 Springboot 应用程序访问 REST 端点时出现问题

Question

I am developing a springboot REST application with Eclipse, but I have a problem deploying it to Tomcat 10.0.22. When I run my application from the IDE the endpoints are working fine, they returns me the correct JSONs but when I try to access them from my server they throw a 404 error. I am packaging it as war. I have created the project from https://start.spring.io/ setting Spring web dependency, java 18 and packaging war. I imported it to eclipse as an existing maven project. To be sure that I deployed it correctly I had created a jsp file and load it as index.jsp and it is showing correctly on the deployed server and the IDE. I have tried to restart the proyect, change the java version in both, export the proyect as jar, to deploy it on another tomcat version, to extend SpringBootServletInitializer from the main class and override the confirm method, without the method implemented and without extending it from anywhere. I don't understand why when I deploy it to the Tomcat server from the Tomcat manager the endpoint calls are throwing a 404 error. I think that is possible that Tomcat is not loading Springboot libraries, because I do not see the console Spring initializing message when I start the server from console, but I do not know how to solve this or if it is what is happening. Can anyone help me please.

This is my main class, TestApplication.java:

package com.testing.test;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

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

This is my servlet initializer application, ServletInitializer.java:

package com.testing.test;
import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.boot.web.servlet.support.SpringBootServletInitializer;

public class ServletInitializer extends SpringBootServletInitializer {
    @Override
    protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
        return application.sources(TestApplication.class);
    }
}

This is my controller, UserController.java:

package com.testing.test.controllers;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class UserController {
    @PostMapping("/test/User")
    public String user(@RequestParam(name="id", defaultValue = "NO_ID_RECEIVED") String id) {
        return String.format("The user ID is: %s",id);      
    }   
}

This is my 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>2.7.0</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.testing</groupId>
    <artifactId>test</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>war</packaging>
    <name>test</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>18</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-tomcat</artifactId>
            <scope>provided</scope>
        </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>

</project>

The mentioned index.jsp:

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
<h2>Let's see if it deploys</h2>
</body>
</html>

EDIT: Because I have had a questions about the structure below this I am appending a picture of it. Project folder structure

Answer 1

Just to be sure have you put your JSP files under web-content and not under WEB-INF because in Eclipse the files are not accessed there by the server. And one more thing try to check server location and see whether Tomcat is installed in the correct server location and it is showing in your Eclipse,if not try changing your server location to the location where Tomcat is installed and restart your server.