Spring custom 404 error page tutorial

last modified October 18, 2023

Spring custom 404 error page tutorial shows how to create custom 404 error pages in a Spring web application.

Spring is a popular Java application framework for creating enterprise applications.

404 code

HTTP 404 or 404 Not Found is a Hypertext Transfer Protocol (HTTP) standard response code, in computer network communications, to indicate that the client was able to communicate with a given server, but the server could not find the requested resource.

Spring custom 404 error page example

The following application uses creates a custom 404 error page. By default, Tomcat’s 404 error page is displayed when the resource cannot be located.

src ├───main │ ├───java │ │ └───com │ │ └───zetcode │ │ ├───config │ │ │ MyWebInitializer.java │ │ │ WebConfig.java │ │ └───controller │ │ ControllerAdvisor.java │ │ MyController.java │ └───resources │ │ logback.xml │ └───templates │ │ index.html │ └───error │ 404.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>custom404page</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>
</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>5.3.23</version>
    </dependency>

    <dependency>
        <groupId>org.thymeleaf</groupId>
        <artifactId>thymeleaf-spring5</artifactId>
        <version>3.0.11.RELEASE</version>
    </dependency>

    <dependency>
        <groupId>org.thymeleaf</groupId>
        <artifactId>thymeleaf</artifactId>
        <version>3.0.11.RELEASE</version>
    </dependency>

</dependencies>

<build>
    <plugins>

        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-war-plugin</artifactId>
            <version>3.3.2</version>
        </plugin>

    </plugins>
</build>

</project>

In the pom.xml file we have the following dependencies: logback-classic, javax.servlet-api, spring-webmvc, and thymeleaf-spring5, and thymeleaf.

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 file.

com/zetcode/config/MyWebInitializer.java

package com.zetcode.config;

import org.springframework.context.annotation.Configuration; import org.springframework.web.context.WebApplicationContext; import org.springframework.web.servlet.DispatcherServlet; import org.springframework.web.servlet.FrameworkServlet; 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[]{"/"};
}

@Override
protected FrameworkServlet createDispatcherServlet(WebApplicationContext servletAppContext) {
    var dispatcher = (DispatcherServlet) super.createDispatcherServlet(servletAppContext);
    dispatcher.setThrowExceptionIfNoHandlerFound(true);
    return dispatcher;
}

}

MyWebInitializer initializes the Spring web application. It contains one configuration class: WebConfig.

@Override protected FrameworkServlet createDispatcherServlet(WebApplicationContext servletAppContext) { var dispatcher = (DispatcherServlet) super.createDispatcherServlet(servletAppContext); dispatcher.setThrowExceptionIfNoHandlerFound(true); return dispatcher; }

With the setThrowExceptionIfNoHandlerFound, we configure Spring to throw NoHandlerFoundException when a resource is not found. If we comment this line, the web server’s 404 error page is shown.

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. The Thymeleaf template files are located in the templates subdirectory on the classpath.

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.time.LocalDateTime;

@Controller public class MyController {

@GetMapping(value = "/", produces = MediaType.TEXT_HTML_VALUE)
public String home(Model model) {

    model.addAttribute("now", LocalDateTime.now());

    return "index";
}

}

MyController contains one route for the home page.

com/zetcode/controller/ControllerAdvisor.java

package com.zetcode.controller;

import org.springframework.web.bind.annotation.ControllerAdvice; import org.springframework.web.bind.annotation.ExceptionHandler; import org.springframework.web.servlet.ModelAndView; import org.springframework.web.servlet.NoHandlerFoundException;

@ControllerAdvice public class ControllerAdvisor {

@ExceptionHandler(NoHandlerFoundException.class)
public ModelAndView handle(Exception ex) {

    var mv = new ModelAndView();
    mv.addObject("message", ex.getMessage());
    mv.setViewName("error/404");

    return mv;
}

}

ControllerAdvisor contains a handler for the NoHandlerFoundException. It shows the 404.html error page, located in resources/templates/error/404.html.

resources/templates/error/404.html

<!doctype html> <html xmlns:th=“http://www.thymeleaf.org”> <head> <meta charset=“UTF-8”> <meta name=“viewport” content=“width=device-width, initial-scale=1.0”> <title>Resource not found</title> </head> <body>

<h2>404 - resource not found</h2>

<p> <span th:text="${message}” th:remove=“tag”></span> </p>

</body> </html>

The 404.html is our custom 404 error page.

resources/templates/index.html

<!DOCTYPE html> <html xmlns:th=“http://www.thymeleaf.org”> <head> <meta charset=“UTF-8”> <title>Home page</title> </head> <body>

<p> This is home page. </p>

<p> Today is <span th:text="${now}"></span> </p> </body> </html>

This is the home page.

In this article we have created a custom 404 error page in a Spring application.

Author

My name is Jan Bodnar, and I am a passionate programmer with extensive programming experience. I have been writing programming articles since 2007. To date, I have authored over 1,400 articles and 8 e-books. I possess more than ten years of experience in teaching programming.

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