Spring Boot application gives 404 when deployed to Tomcat but works with embedded server

Java Maven Spring Mvc Tomcat Spring Boot

Java Problem Overview

Guided by Serving Web Content with Spring MVC, I'm creating a Spring Boot web application that I can run using both the embedded Tomcat instance as well as on a standalone Tomcat 8 server.

The application works as expected when executed as java -jar adminpage.war and I see the expected outcome when I visit http://localhost:8080/table. However, when I deploy to a Tomcat 8 server (by dropping adminpage.war into the webapps directory), I get a 404 error when I visit https://myserver/adminpage/table.

The catelina.log and localhost.log files contain nothing helpful on the Tomcat server.

Can anyone suggest where I've made a misconfiguration? I've not had the same problems in the past when deploying RESTful services with Spring Boot, but this is my first foray into a web application.

My application files:

src/main/java/com/.../Application.java

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

}

src/main/java/com/.../MainController.java

@Controller
public class MainController {

    @RequestMapping("/table")
    public String greeting(Model model) {
        model.addAttribute("name", "Fooballs");
        return "table";
    }
}

src/main/resources/templates/table.html

<!DOCTYPE HTML>
<html xmlns:th="http://www.thymeleaf.org">
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
</head>
<body>
    <p th:text="'Hello, ' + ${name} + '!'" />
</body>
</html>

pom.xml

<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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.foo</groupId>
  <artifactId>adminpage</artifactId>
  <version>1.0-SNAPSHOT</version>
  <packaging>war</packaging>

  <parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>1.4.0.RELEASE</version>
  </parent>

  <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-thymeleaf</artifactId>
    </dependency>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-devtools</artifactId>
      <optional>true</optional>
    </dependency>
  </dependencies>

  <properties>
    <java.version>1.8</java.version>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  </properties>


  <build>
    <finalName>adminpage</finalName>

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

</project>

Java Solutions

Solution 1 - Java

I had forgotten to tweak my Application.java file to extend SpringBootServletInitializer and override the configure method.

Corrected file:

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

  @Override
  protected SpringApplicationBuilder configure(SpringApplicationBuilder builder) {
      return builder.sources(Application.class);
  }
}

Hat tip to https://mtdevuk.com/2015/07/16/how-to-make-a-spring-boot-jar-into-a-war-to-deploy-on-tomcat/ for pointing out my mistake.

More info at Create a deployable war file in Spring Boot Official docs.

Solution 2 - Java

As of August 2021 . If anyone facing this issue in Tomcat 10 server, just read in the below post that Spring boot won't work in Tomcat 10. https://github.com/spring-projects/spring-boot/issues/22414

I had faced this issue and switching to an previous version, which resolved the problem.

Solution 3 - Java

In case anyone having same problem while using sprint boot in the IntelliJ community edition. You just need to put your main class in the main package (com.xyx) don't put it in any subpackage which is created inside com.xyx.

Solution 4 - Java

Downgrading Tomcat from version 10 to 9 did the trick for me. Update January 2022, apparently tomcat 10 still does not support spring-boot. As mentioned by Dipu over here, https://stackoverflow.com/a/68917349/13294956

Solution 5 - Java

Just add the route in the controller annotation, something like this: @RestController @RequestMapping(value = "/")

Solution 6 - Java

For me, the Spring boot wasn't work with tomcat 10. I changed for 9 version and it worked.

Content Type	Original Author	Original Content on Stackoverflow
Question	Duncan Jones	View Question on Stackoverflow
Solution 1 - Java	Duncan Jones	View Answer on Stackoverflow
Solution 2 - Java	Dipu Krishnan	View Answer on Stackoverflow
Solution 3 - Java	Hanumant	View Answer on Stackoverflow
Solution 4 - Java	Achintya Shivam	View Answer on Stackoverflow
Solution 5 - Java	Diego Mejia	View Answer on Stackoverflow
Solution 6 - Java	CesarJunior	View Answer on Stackoverflow