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.
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.
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.
<?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.
<?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.
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.
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.
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.
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.
<!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="${message}" th:remove="tag"></span>
</p>
</body>
</html>
The 404.html is our custom 404 error page.
<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
<head>
<meta charset="UTF-8">
<title>Home page</title>
</head>
<body>
<p>
This is home page.
</p>
<p>
Today is <span th:text="${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.
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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