Spring 中的 404 错误（java config / no web.xml）

Question

尝试在 Web 应用程序中提供自定义 404 错误页面，据我所知，该页面使用 Java Config（因此没有 web.xml）。我们有以下版本的相关库：spring ("5.1.2.RELEASE")、spring-security ("5.1.1.RELEASE")。免责声明我在 StackOverflow 中检查了不同的方法。请不要为 web.xml、Thymeleaf 或 Spring Boot 推荐结果。这不适用。其中; 我尝试了以下方法：@Controller注释（这里和这里）添加 web.xml没有产生预期的结果（即，仍然得到默认的网络服务器布局和错误）。

Answer 1

虽然没有我想的那么清楚，但这是一种工作版本，至少可以为错误页面提供一些自定义。这是第一种方法，但希望可以帮助其他人。

处理的异常列表并不广泛，但主要解决 404 错误 ( NoHandlerFoundException) 和其他典型错误，例如InternalServerErrorExceptionand NullPointerException，尝试在最后捕获所有异常，并为所有其他是 a 的错误提供通用错误Exception)。

请注意，这不包括与例如 JSTL 模板中的错误语法相关的其他异常（org.apache.jasper.*; 显然无法在此处捕获的异常）。

这些是源库的相关更改和添加：

CustomSimpleMappingExceptionResolver.java（提供通用异常，但记录详细信息）

package ...;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.Date;

import javax.ws.rs.InternalServerErrorException;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import org.springframework.http.HttpStatus;

import org.springframework.web.servlet.handler.SimpleMappingExceptionResolver;

import org.springframework.web.servlet.ModelAndView;

import org.springframework.web.servlet.NoHandlerFoundException;

public class CustomSimpleMappingExceptionResolver extends SimpleMappingExceptionResolver {

    public CustomSimpleMappingExceptionResolver() {

        // Turn logging on by default

        setWarnLogCategory(getClass().getName());

    }

    @Override

    public String buildLogMessage(Exception e, HttpServletRequest req) {

        return "MVC exception: " + e.getLocalizedMessage();

    }

    @Override

    protected ModelAndView doResolveException(HttpServletRequest request, HttpServletResponse response,

                                              Object handler, Exception ex) {

        // Log exception

        ex.printStackTrace();

        String exceptionCause = ex.toString();

        String exceptionType = ex.getClass().getCanonicalName();

        // Get the ModelAndView to use

        ModelAndView mav = super.doResolveException(request, response, handler, ex);

        // Make more information available to the view - note that SimpleMappingExceptionResolver adds the exception already

        mav.addObject("url", request.getRequestURL());

        mav.addObject("timestamp", new Date());

        ArrayList<String> exceptions404 = new ArrayList<String>(

                Arrays.asList(

                        NoHandlerFoundException.class.getName()

                        )

        );

        ArrayList<String> exceptions500 = new ArrayList<String>(

                Arrays.asList(

                        InternalServerErrorException.class.getName(),

                        NullPointerException.class.getName()

                        )

        );

        String userExceptionDetail = ex.toString();

        String errorHuman = "";

        String errorTech = "";

        if (exceptions404.contains(exceptionType)) {

            errorHuman = "We cannot find the page you are looking for";

            errorTech = "Page not found";

            userExceptionDetail = String.format("The page %s cannot be found", request.getRequestURL());

            mav.setViewName("/error/404");

            mav.addObject("status", HttpStatus.NOT_FOUND.value());

        } else if (exceptions500.contains(exceptionType)) {

            errorHuman = "We cannot currently serve the page you request";

            errorTech = "Internal error";

            userExceptionDetail = "The current page refuses to load due to an internal error";

            mav.setViewName("/error/500");

            mav.addObject("status", HttpStatus.INTERNAL_SERVER_ERROR.value());

        } else {

            errorHuman = "We cannot serve the current page";

            errorTech = "General error";

            userExceptionDetail = "A generic error prevents from serving the page";

            mav.setViewName("/error/generic");

            mav.addObject("status", response.getStatus());

        }

        Exception userException = new Exception(userExceptionDetail);

        mav.addObject("error_human", errorHuman);

        mav.addObject("error_tech", errorTech);

        mav.addObject("exception", userException);

        return mav;

    }

}

WebAppConfig.java（将自定义异常解析器注册为异常处理程序）

package ...;

import org.springframework.context.annotation.Bean;

import org.springframework.context.annotation.ComponentScan;

import org.springframework.context.annotation.Configuration;

import org.springframework.context.annotation.PropertySource;

import org.springframework.context.annotation.Scope;

import org.springframework.context.annotation.ScopedProxyMode;

import org.springframework.core.env.Environment;

import org.springframework.core.Ordered;

import org.springframework.http.HttpStatus;

import org.springframework.transaction.annotation.EnableTransactionManagement;

import org.springframework.web.servlet.config.annotation.EnableWebMvc;

import org.springframework.web.servlet.config.annotation.ViewControllerRegistry;

import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;

import org.springframework.web.servlet.HandlerExceptionResolver;

import org.springframework.web.servlet.NoHandlerFoundException;

import org.springframework.web.servlet.view.InternalResourceViewResolver;

import java.lang.ClassNotFoundException;

import java.lang.NullPointerException;

import javax.annotation.Resource;

import javax.ws.rs.InternalServerErrorException;

import java.util.Properties;

@Configuration

@ComponentScan("...")

@EnableWebMvc

@EnableTransactionManagement

@PropertySource("classpath:application.properties")

public class WebAppConfig extends WebMvcConfigurerAdapter {

    @Resource

    private Environment env;

    // ...

    @Bean

    HandlerExceptionResolver customExceptionResolver () {

        CustomSimpleMappingExceptionResolver resolver = new CustomSimpleMappingExceptionResolver();

        Properties mappings = new Properties();

        // Mapping Spring internal error NoHandlerFoundException to a view name

        mappings.setProperty(NoHandlerFoundException.class.getName(), "/error/404");

        mappings.setProperty(InternalServerErrorException.class.getName(), "/error/500");

        mappings.setProperty(NullPointerException.class.getName(), "/error/500");

        mappings.setProperty(ClassNotFoundException.class.getName(), "/error/500");

        mappings.setProperty(Exception.class.getName(), "/error/generic");

        resolver.setExceptionMappings(mappings);

        // Set specific HTTP codes

        resolver.addStatusCode("404", HttpStatus.NOT_FOUND.value());

        resolver.addStatusCode("500", HttpStatus.INTERNAL_SERVER_ERROR.value());

        resolver.setDefaultErrorView("/error/generic");

        resolver.setDefaultStatusCode(200);

        // This resolver will be processed before the default ones

        resolver.setOrder(Ordered.HIGHEST_PRECEDENCE);

        resolver.setExceptionAttribute("exception");

        return resolver;

    }

    // ...

    @Bean

    public InternalResourceViewResolver setupViewResolver() {

        InternalResourceViewResolver resolver = new InternalResourceViewResolver();

        resolver.setPrefix("/WEB-INF/views");

        resolver.setSuffix(".jsp");

        resolver.setExposeContextBeansAsAttributes(true);

        return resolver;

    }

    @Override

    public void addViewControllers(ViewControllerRegistry registry) {

        super.addViewControllers(registry);

    }

}

Initializer.java（添加dispatcherServlet.setThrowExceptionIfNoHandlerFound(true);；可能不需要）

package ...;

import org.springframework.web.WebApplicationInitializer;

import org.springframework.web.context.ContextLoaderListener;

import org.springframework.web.context.support.AnnotationConfigWebApplicationContext;

import org.springframework.web.servlet.DispatcherServlet;

import javax.servlet.ServletContext;

import javax.servlet.ServletException;

import javax.servlet.ServletRegistration;

public class Initializer implements WebApplicationInitializer {

    public void onStartup(ServletContext servletContext) throws ServletException {

        AnnotationConfigWebApplicationContext ctx = new AnnotationConfigWebApplicationContext();

        ctx.register(WebAppConfig.class);

        servletContext.addListener(new ContextLoaderListener(ctx));

        ctx.setServletContext(servletContext);

        DispatcherServlet dispatcherServlet = new DispatcherServlet(ctx);

        dispatcherServlet.setThrowExceptionIfNoHandlerFound(true);

        // Add the dispatcher servlet mapping manually and make it initialize automatically

        ServletRegistration.Dynamic servlet = servletContext.addServlet("dispatcher", dispatcherServlet);

        servlet.addMapping("/");

        servlet.addMapping("*.png");

        servlet.addMapping("*.jpg");

        servlet.addMapping("*.css");

        servlet.addMapping("*.js");

        servlet.addMapping("*.txt");

        servlet.setLoadOnStartup(1);

        // ...

    }

}

与错误类相关的视图和标签的结构：

    src/main/webapp/WEB-INF/

    ├── tags

    │   └── error.tag

    └── views

        ├── error

        │   ├── 404.jsp

        │   ├── 500.jsp

        └────── generic.jsp

src/main/webapp/WEB-INF/tags/error.tag

<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>

<!DOCTYPE html>

<head>

    <title>Error page</title>

</head>

<body>

<div class="container">

    <h3><c:out value="${error_human}" /></h3>

    <p><br/><br/></p>

    <div class="panel panel-primary">

        <div class="panel-heading">

            <c:out value="${error_tech}" />

        </div>

        <div class="panel-body">

            <p><c:out value="${exception_message}" /></p>

        </div>

    </div>

</div>

</body>

</html>

src/main/webapp/WEB-INF/views/error/404.jsp

<%@ page language="java" contentType="text/html; charset=utf-8"

         pageEncoding="utf-8" isErrorPage="true" %>

<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>

<%@ taglib tagdir="/WEB-INF/tags/" prefix="g" %>

<c:set var = "error_human" scope = "session" value = "We cannot find the page you are looking for"/>

<c:set var = "error_tech" scope = "session" value = "Page not found"/>

<c:set var = "exception_message" scope = "session" value = "The current page cannot be found"/>

<g:error />

src/main/webapp/WEB-INF/views/error/500.jsp

<%@ page language="java" contentType="text/html; charset=utf-8"

         pageEncoding="utf-8" isErrorPage="true" %>

<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>

<%@ taglib tagdir="/WEB-INF/tags/" prefix="g" %>

<c:set var = "error_human" scope = "session" value = "We cannot currently serve the page you request"/>

<c:set var = "error_tech" scope = "session" value = "Internal error"/>

<c:set var = "exception_message" scope = "session" value = "The current page refuses to load due to an internal error"/>

<g:error />

src/main/webapp/WEB-INF/views/error/generic.jsp

<%@ page language="java" contentType="text/html; charset=utf-8"

         pageEncoding="utf-8" isErrorPage="true" %>

<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>

<%@ taglib tagdir="/WEB-INF/tags/" prefix="g" %>

<c:set var = "error_human" scope = "session" value = "We cannot serve the current page"/>

<c:set var = "error_tech" scope = "session" value = "General error"/>

<c:set var = "exception_message" scope = "session" value = "A generic error prevents from serving the page"/>

<g:error />

Answer 2

阅读 Spring Boot 文档，这对我有用：

  @Bean

   public ErrorPageRegistrar errorPageRegistrar() {

     return registry -> registry.addErrorPages(new ErrorPage(HttpStatus.NOT_FOUND, "/index.html"));  }

这相当于 web.xml。

Answer 3

确保您可以访问 404 页面，然后添加这些代码。

@ControllerAdvice

public class GlobalExceptionHandler {

    @ResponseStatus(HttpStatus.NOT_FOUND)

    @ExceptionHandler(NoHandlerFoundException.class)

    public String handle404(Model model, HttpServletRequest req, Exception ex) {

        return "/404";

    }

}

应用程序.yaml

spring:

  mvc:

    throwExceptionIfNoHandlerFound: true # if page not found, it will throw error, and then ControllerAdvice will catch the error.

PS：springBoot版本=2.4.2；爪哇=15