In the previous article, we have added logging support using the Logback logging framework. Now, we are going to add embedded tomcat to the Spring REST application without using Spring Boot.
Let’s Get Started
Add Tomcat Dependencies and Shade Plugin
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/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.javachinna</groupId>
<artifactId>spring-rest-jwt-demo</artifactId>
<packaging>jar</packaging>
<version>0.0.1-SNAPSHOT</version>
<name>spring-rest-jwt-demo Maven Webapp</name>
<url>http://maven.apache.org</url>
<properties>
<java-version>11</java-version>
<spring.version>5.2.3.RELEASE</spring.version>
<hibernate.version>5.4.1.Final</hibernate.version>
<tomcat.version>9.0.37</tomcat.version>
<slf4j.version>1.7.25</slf4j.version>
</properties>
<dependencies>
<!-- Spring Web MVC -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>${spring.version}</version>
</dependency>
<!-- Required for converting JSON data to Java object and vice versa -->
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.9.10.5</version>
</dependency>
<!-- Servlet API -->
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>4.0.1</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-classic</artifactId>
<version>1.2.3</version>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>jul-to-slf4j</artifactId>
<version>${slf4j.version}</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>log4j-over-slf4j</artifactId>
<version>${slf4j.version}</version>
</dependency>
<dependency>
<groupId>org.springframework.security</groupId>
<artifactId>spring-security-web</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework.security</groupId>
<artifactId>spring-security-config</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>io.jsonwebtoken</groupId>
<artifactId>jjwt</artifactId>
<version>0.9.1</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-orm</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework.data</groupId>
<artifactId>spring-data-jpa</artifactId>
<version>2.2.6.RELEASE</version>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-core</artifactId>
<version>${hibernate.version}</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.16</version>
<scope>runtime</scope>
</dependency>
<!-- https://mvnrepository.com/artifact/org.apache.tomcat.embed/tomcat-embed-core -->
<dependency>
<groupId>org.apache.tomcat.embed</groupId>
<artifactId>tomcat-embed-core</artifactId>
<version>${tomcat.version}</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.apache.tomcat.embed/tomcat-embed-jasper -->
<dependency>
<groupId>org.apache.tomcat.embed</groupId>
<artifactId>tomcat-embed-jasper</artifactId>
<version>${tomcat.version}</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.threeten/threetenbp -->
<dependency>
<groupId>org.threeten</groupId>
<artifactId>threetenbp</artifactId>
<version>1.4.2</version>
</dependency>
</dependencies>
<build>
<finalName>SpringRestJwt</finalName>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>2.3.2</version>
<configuration>
<source>${java-version}</source>
<target>${java-version}</target>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-shade-plugin</artifactId>
<version>3.2.4</version>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>shade</goal>
</goals>
<configuration>
<transformers>
<transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
<mainClass>com.javachinna.embedded.TomcatLauncher</mainClass>
</transformer>
<transformer implementation="org.apache.maven.plugins.shade.resource.AppendingTransformer">
<resource>META-INF/spring.handlers</resource>
</transformer>
<transformer implementation="org.apache.maven.plugins.shade.resource.AppendingTransformer">
<resource>META-INF/spring.schemas</resource>
</transformer>
<transformer implementation="org.apache.maven.plugins.shade.resource.AppendingTransformer">
<resource>META-INF/spring.factories</resource>
</transformer>
</transformers>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>
</project>
List of Changes
- Changed the packaging type to jar
- Upgraded Servlet API version from 3.0.1 to 4.0.1 to make it compatible with Tomcat 9.0 version
- Added embedded tomcat core and Jasper (JSP engine) dependencies
- Upgraded
spring-data-jpato 2.2.6.RELEASE version - Added
threetenbpdependency which is required forspring-data-jpa - Added
maven-shade-pluginto build a fat jar and configuredtransformersManifestResourceTransformerused for configuring our Main classTomcatLauncher- Each Spring jar has configuration files like
spring.handlers,spring.schemas,andspring.factoriesin the META-INF directory. The default behavior of the shade plugin is to overwrite those files. To avoid this,AppendingTransformeris being used for appending the contents into a single file.
Create Main Class
TomcatLauncher.java
This class is responsible for adding our application to the embedded tomcat server and starting it on port 8080
package com.javachinna.embedded;
import java.io.File;
import org.apache.catalina.startup.Tomcat;
public class TomcatLauncher {
public static void main(String[] args) throws Exception {
Tomcat tomcat = new Tomcat();
tomcat.setPort(8080);
tomcat.addWebapp("", new File("src/main/").getAbsolutePath());
tomcat.getConnector();
tomcat.start();
tomcat.getServer().await();
}
}
Build Application
You can build a fat jar by executing mvn package command in your source directory
Run Application
You can run the application by running java -jar target\SpringRestJwt.jar command in your source directory
Source code
https://github.com/JavaChinna/spring-rest-embedded-tomcat
Conclusion
That’s all folks. In this article, we have embedded tomcat into our Spring REST application.
Please share this article with your friends if you like it. Thank you for reading.
