Spring Jetty
last modified October 18, 2023
In this article, we show how to run Spring web application on Jetty web server.
Spring is a popular Java application framework for creating enterprise applications.
Jetty
Jetty Web Server is an HTTP server and Servlet container capable of serving static and dynamic content either from a standalone or embedded instantiations.
Spring Jetty example
In the following example, we create a simple Spring web application and deploy it
on the Jetty web server. For this, we use the jetty-maven-plugin.
The application displays a couple of English words.
pom.xml
src
├───main
│ ├───java
│ │ └───com
│ │ └───zetcode
│ │ ├───config
│ │ │ MyWebInitializer.java
│ │ │ WebConfig.java
│ │ └───controller
│ │ MyController.java
│ └───resources
│ │ logback.xml
│ └───templates
│ index.html
└───test
└───java
This is the project structure.
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>com.zetcode</groupId>
<artifactId>SpringJettyEx</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>war</packaging>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.source>17</maven.compiler.source>
<maven.compiler.target>17</maven.compiler.target>
<spring-version>5.3.23</spring-version>
<thymeleaf-version>3.0.15.RELEASE</thymeleaf-version>
</properties>
<dependencies>
<dependency>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-classic</artifactId>
<version>1.4.0</version>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>4.0.1</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>${spring-version}</version>
</dependency>
<dependency>
<groupId>org.thymeleaf</groupId>
<artifactId>thymeleaf-spring5</artifactId>
<version>${thymeleaf-version}</version>
</dependency>
<dependency>
<groupId>org.thymeleaf</groupId>
<artifactId>thymeleaf</artifactId>
<version>${thymeleaf-version}</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-war-plugin</artifactId>
<version>3.3.2</version>
</plugin>
<plugin>
<groupId>org.eclipse.jetty</groupId>
<artifactId>jetty-maven-plugin</artifactId>
<version>9.4.49.v20220914</version>
</plugin>
</plugins>
</build>
</project>
In the pom.xml we have the project dependencies.
<plugin>
<groupId>org.eclipse.jetty</groupId>
<artifactId>jetty-maven-plugin</artifactId>
<version>9.4.49.v20220914</version>
</plugin>
The jetty-maven-plugin allows us to run embedded Jetty server with
mvn jetty:run.
resources/logback.xml
<?xml version="1.0" encoding="UTF-8"?>
<configuration>
<logger name="org.springframework" level="ERROR"/>
<logger name="com.zetcode" level="INFO"/>
<appender name="consoleAppender" class="ch.qos.logback.core.ConsoleAppender">
<encoder>
<Pattern>%d{HH:mm:ss.SSS} %blue(%-5level) %magenta(%logger{36}) - %msg %n
</Pattern>
</encoder>
</appender>
<root>
<level value="INFO" />
<appender-ref ref="consoleAppender" />
</root>
</configuration>
This is the logback.xml configuration
com/zetcode/config/MyWebInitializer.java
package com.zetcode.config;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;
@Configuration
public class MyWebInitializer extends
AbstractAnnotationConfigDispatcherServletInitializer {
@Override
protected Class[] getRootConfigClasses() {
return null;
}
@Override
protected Class[] getServletConfigClasses() {
return new Class[]{WebConfig.class};
}
@Override
protected String[] getServletMappings() {
return new String[]{"/"};
}
}
MyWebInitializer initializes the Spring web application. It
contains one configuration class: WebConfig.
com/zetcode/config/WebConfig.java
package com.zetcode.config;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.ViewResolver;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.ViewResolverRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
import org.thymeleaf.spring5.SpringTemplateEngine;
import org.thymeleaf.spring5.templateresolver.SpringResourceTemplateResolver;
import org.thymeleaf.spring5.view.ThymeleafViewResolver;
@Configuration
@EnableWebMvc
@ComponentScan(basePackages = {"com.zetcode"})
public class WebConfig implements WebMvcConfigurer {
@Autowired
private ApplicationContext applicationContext;
@Bean
public SpringResourceTemplateResolver templateResolver() {
var templateResolver = new SpringResourceTemplateResolver();
templateResolver.setApplicationContext(applicationContext);
templateResolver.setPrefix("classpath:/templates/");
templateResolver.setSuffix(".html");
return templateResolver;
}
@Bean
public SpringTemplateEngine templateEngine() {
var templateEngine = new SpringTemplateEngine();
templateEngine.setTemplateResolver(templateResolver());
templateEngine.setEnableSpringELCompiler(true);
return templateEngine;
}
@Bean
public ViewResolver viewResolver() {
var resolver = new ThymeleafViewResolver();
var registry = new ViewResolverRegistry(null, applicationContext);
resolver.setTemplateEngine(templateEngine());
registry.viewResolver(resolver);
return resolver;
}
}
The WebConfig configures the Thymeleaf template engine.
com/zetcode/controller/MyController.java
package com.zetcode.controller;
import org.springframework.http.MediaType;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.GetMapping;
import java.util.List;
@Controller
public class MyController {
@GetMapping(value = "/", produces = MediaType.TEXT_HTML_VALUE)
public String home(Model model) {
var words = List.of("mountain", "noon", "rock", "river", "spring");
model.addAttribute("words", words);
return "index";
}
}
MyController contains one route for the home page. We send some
data to the template. The data will be presented in an HTML table.
resources/templates/index.html
<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
<head>
<meta charset="UTF-8">
<title>Home page</title>
</head>
<body>
<h2>English words</h2>
<table">
<thead>
<tr>
<th>Index</th>
<th>Word</th>
</tr>
</thead>
<tbody>
<tr th:each="word : ${words}">
<td th:text="${wordStat.index + 1}">Index</td>
<td th:text="${word}">A word</td>
</tr>
</tbody>
</table>
</body>
</html>
This is the home page.
$ mvn jetty:run
We run the Jetty server. We navigate to the localhost:8080 to get
the home page.
In this article, we have created a classic Spring web application and deployed it on embedded Jetty server.
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