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.
<?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.
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