War file not getting executed in tomcat

Question

I am new to web application development.

I have been working on developing a rest web service and deploying it locally on apache tomcat server. I am using sts for this.

Now, when I am executing my application from sts (Run as java application). It is running fine. I am hitting the url at localhost:8080 and everything is fine.

Now, I am doing the following :

1. Created a .war file for my application, named sample-rest-service.war
2. On a different system, I have downloaded and installed tomcat 8 configured to run on port 9999
3. I copy my .war file in the webapps folder of apache-tomcat-8.028
4. I start my tomcat server using startup.sh
5. I type localhost:9999 in my browser and the home page appears
6. I type localhost:9999/sample-rest-service, but I get the error message with code 404
7. I type localhost:9999/examples and it works fine, i.r. content appears
8. I check the webapps folder, .war file has been extracted both war file and the extracted folder are present there.

What am I missing ?

Normally if I run my application through sts, I do this :

1. Run as Java Application
2. Then it asks me to chose, I chose Application-hello, where Application is the class having main() and hello is the package
3. After that in the console I can read the message that Tomcat started on port(s): 8080 (http)
4. Now in my browser I type this : http://localhost:8080/greeting
5. I get the output in JSON

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" version="3.1">
  <display-name>sample-rest-service</display-name>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>
</web-app>

To generate war I did the following :

1. Added the maven war plugin in my project
2. changed the packaging in pom.xml from jar(default) to war
3. Export war file

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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>org.springframework</groupId>
    <artifactId>gs-rest-service</artifactId>
    <version>0.1.0</version>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.2.6.RELEASE</version>
    </parent>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>                            
    </dependencies>

    <properties>
        <java.version>1.7</java.version>
    </properties>


    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-war-plugin</artifactId>
                <version>2.6</version>
            </plugin>
        </plugins>
    </build>

    <repositories>
        <repository>
            <id>spring-releases</id>
            <url>https://repo.spring.io/libs-release</url>
        </repository>
    </repositories>
    <pluginRepositories>
        <pluginRepository>
            <id>spring-releases</id>
            <url>https://repo.spring.io/libs-release</url>
        </pluginRepository>
    </pluginRepositories>


    <packaging>war</packaging>
</project>

Answer 1

It turns out that the whole problem was with building the war file.

The proper way to build a deployable and runnable war file through sts is explained here

1. Extend your Application class with SpringBootServletInitializer, and override the configure method

   @SpringBootApplication public class Application extends SpringBootServletInitializer{

   public static void main(String[] args) {
       SpringApplication.run(Application.class, args);
   }
   
   @Override
   protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
       return application.sources(Application.class);
   }
   

2. In pom.xml, mention war inside packaging tags

3. you need to mark the spring-boot-starter-tomcat dependencies as “provided”