如何替换嵌入式Tomcat中“未找到对应网页”的提示信息？

嘿，针对你用Spring Boot 1.3.3（嵌入式Tomcat）搭配Spring Web MVC 4.2.5的场景，要替换默认的404提示信息，我给你整理了几种靠谱的实现方式，按需选就行：

方法1：自定义ErrorController（最灵活的动态处理） #

Spring Boot默认用BasicErrorController处理错误请求，我们可以自己实现ErrorController接口，完全掌控错误响应的内容。

示例代码（返回JSON格式） #

如果需要返回自定义JSON提示，用@RestController：

import org.springframework.boot.autoconfigure.web.ErrorController;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import javax.servlet.http.HttpServletRequest;
import java.util.HashMap;
import java.util.Map;

@RestController
public class CustomErrorController implements ErrorController {

    private static final String ERROR_PATH = "/error";

    @RequestMapping(value = ERROR_PATH)
    public Map<String, Object> handleError(HttpServletRequest request) {
        Map<String, Object> response = new HashMap<>();
        // 获取请求状态码和路径
        Integer statusCode = (Integer) request.getAttribute("javax.servlet.error.status_code");
        String requestUri = (String) request.getAttribute("javax.servlet.error.request_uri");
        
        if (statusCode == 404) {
            response.put("code", 404);
            response.put("message", String.format("抱歉，你访问的路径「%s」不存在", requestUri));
        } else {
            response.put("code", statusCode);
            response.put("message", "服务器临时故障，请稍后再试");
        }
        return response;
    }

    @Override
    public String getErrorPath() {
        return ERROR_PATH;
    }
}

示例代码（返回模板视图） #

如果用Thymeleaf等模板引擎，换成@Controller返回视图：

import org.springframework.boot.autoconfigure.web.ErrorController;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;

@Controller
public class CustomErrorController implements ErrorController {

    private static final String ERROR_PATH = "/error";

    @RequestMapping(value = ERROR_PATH)
    public ModelAndView handleError(HttpServletRequest request) {
        ModelAndView mv = new ModelAndView();
        Integer statusCode = (Integer) request.getAttribute("javax.servlet.error.status_code");
        String requestUri = (String) request.getAttribute("javax.servlet.error.request_uri");
        
        if (statusCode == 404) {
            mv.addObject("requestUri", requestUri);
            mv.setViewName("error/404"); // 对应templates/error/404.html模板
        } else {
            mv.setViewName("error/5xx");
        }
        return mv;
    }

    @Override
    public String getErrorPath() {
        return ERROR_PATH;
    }
}

方法2：全局异常处理器（针对404异常） #

Spring MVC默认不会抛出路径找不到的异常，需要先开启配置，再用全局异常处理器捕获处理。

步骤1：开启NoHandlerFoundException #

创建Web配置类，开启抛出路径未找到的异常：

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

import javax.servlet.ServletRegistration;

@Configuration
public class WebMvcConfig extends WebMvcConfigurerAdapter {

    @Override
    public void configureDispatchServlet(ServletRegistration.Dynamic registration) {
        // 关键：开启路径未找到时抛出异常
        registration.setInitParameter("throwExceptionIfNoHandlerFound", "true");
    }
}

步骤2：全局捕获404异常 #

创建全局异常处理类，用@RestControllerAdvice（或@ControllerAdvice）处理：

import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RestControllerAdvice;
import org.springframework.web.servlet.NoHandlerFoundException;

import javax.servlet.http.HttpServletRequest;
import java.util.HashMap;
import java.util.Map;

@RestControllerAdvice
public class GlobalExceptionHandler {

    @ExceptionHandler(NoHandlerFoundException.class)
    public Map<String, Object> handle404Error(NoHandlerFoundException e, HttpServletRequest request) {
        Map<String, Object> response = new HashMap<>();
        response.put("code", 404);
        response.put("message", String.format("自定义提示：页面「%s」不存在", request.getRequestURI()));
        return response;
    }
}

方法3：自定义静态错误页面（简单直接） #

如果只需要静态HTML提示，直接配置Tomcat映射错误页面即可。

步骤1：配置Tomcat错误页面映射 #

创建配置类注册EmbeddedServletContainerCustomizer：

import org.springframework.boot.context.embedded.EmbeddedServletContainerCustomizer;
import org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainerFactory;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class TomcatErrorConfig {

    @Bean
    public EmbeddedServletContainerCustomizer containerCustomizer() {
        return container -> {
            if (container instanceof TomcatEmbeddedServletContainerFactory) {
                TomcatEmbeddedServletContainerFactory tomcatFactory = (TomcatEmbeddedServletContainerFactory) container;
                // 映射404状态码到静态页面
                tomcatFactory.addErrorPages(new org.springframework.boot.context.embedded.ErrorPage(
                        org.springframework.http.HttpStatus.NOT_FOUND, "/404.html"));
            }
        };
    }
}

步骤2：创建静态404页面 #

在src/main/resources/static目录下创建404.html，内容自定义：

<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <title>页面不存在</title>
</head>
<body>
    <h2>😯 哎呀，你找的页面跑丢了！</h2>
    <p>你访问的路径：<span id="currentPath"></span></p>
    <script>
        document.getElementById('currentPath').textContent = window.location.href;
    </script>
</body>
</html>

内容的提问来源于stack exchange，提问作者user299702