统一异常拦截及自定义错误跳转

src/main/java/cc/bnblogs/Exception/CustomException.java

@@ -0,0 +1,8 @@
+package cc.bnblogs.Exception;
+
+/**
+ * @author zfp@bnblogs.cc
+ * @createTime: 2022/10/23
+ */
+public class CustomException extends Exception{
+}

src/main/java/cc/bnblogs/config/ExceptionConfig.java

@@ -1,10 +1,16 @@
 package cc.bnblogs.config;
 
+import cc.bnblogs.Exception.CustomException;
 import cc.bnblogs.common.Result;
+import com.fasterxml.jackson.databind.ObjectMapper;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.web.bind.annotation.ControllerAdvice;
 import org.springframework.web.bind.annotation.ExceptionHandler;
-import org.springframework.web.bind.annotation.ResponseBody;
+
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import java.io.IOException;
 
 /**
  * @author zfp@bnblogs.cc
@@ -14,11 +20,30 @@ import org.springframework.web.bind.annotation.ResponseBody;
 @ControllerAdvice
 public class ExceptionConfig {
 
-    @ResponseBody
     @ExceptionHandler(Exception.class)
-    public Result<String> defaultException(Exception e) {
+    public void defaultException(Exception e, HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
+        e.printStackTrace();
+        log.error(e.getMessage(), e);
+        // 返回的是页面
+        if (request.getRequestURI().endsWith(".html")) {
+            request.getRequestDispatcher("/error/500.html").forward(request, response);
+        } else {
+            // 返回的是json
+            response.setCharacterEncoding("utf-8");
+            response.getWriter().print(new ObjectMapper().writeValueAsString(Result.error()));
+        }
+    }
+
+    /**
+     * http状态码虽然是200，当业务上有错误(比如访问的文章、分类、标签不存在时)
+     * 当业务上存在404时，统一转发到/error/404.html
+     * @param e 自定义错误异常类
+     * @return 404.html
+     */
+    @ExceptionHandler(CustomException.class)
+    public String notFoundException(CustomException e) {
         e.printStackTrace();
         log.error(e.getMessage(),e);
-        return Result.error();
+        return "forward:/error/404.html";
     }
 }

src/main/java/cc/bnblogs/config/WebConfig.java

@@ -1,13 +1,22 @@
 package cc.bnblogs.config;
 
 import cc.bnblogs.common.LRUCache;
+import cc.bnblogs.common.Result;
+import com.fasterxml.jackson.databind.ObjectMapper;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.beans.factory.annotation.Value;
+import org.springframework.boot.web.server.ConfigurableWebServerFactory;
+import org.springframework.boot.web.server.ErrorPage;
+import org.springframework.boot.web.server.WebServerFactoryCustomizer;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.http.HttpStatus;
+import org.springframework.web.bind.annotation.ExceptionHandler;
 import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
 import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
 
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
 import java.io.File;
 
 /**
@@ -41,6 +50,18 @@ public class WebConfig implements WebMvcConfigurer {
         // 记住在absolutePath前加一个'/',否则本地图片读取不出来(重要的事情说三遍)
         registry.addResourceHandler("/upload/**").addResourceLocations("file://" + '/' + absolutePath);
     }
+
+    /**
+     * 错误页面配置是根据HTTP请求返回的状态码决定的(Http异常)
+     * Controller层的报错是thymeleaf渲染页面时报错的(业务异常)
+     * @return 跳转到对应的error页面
+     */
+    @Bean
+    public WebServerFactoryCustomizer<ConfigurableWebServerFactory> webServerFactoryCustomizer() {
+        return factory -> factory.addErrorPages(
+                new ErrorPage(HttpStatus.NOT_FOUND, "/error/404.html"),
+                new ErrorPage(HttpStatus.INTERNAL_SERVER_ERROR, "/error/500.html"));
+    }
     @Bean
     public LRUCache lruCache() {
         return new LRUCache(MAX_LRU_CACHE_SIZE);

src/main/java/cc/bnblogs/controller/IndexController.java

@@ -1,7 +1,9 @@
 package cc.bnblogs.controller;
 
+import cc.bnblogs.Exception.CustomException;
 import cc.bnblogs.common.*;
 import cc.bnblogs.config.WebConfig;
+import cc.bnblogs.enums.ErrorCodeEnum;
 import cc.bnblogs.enums.ResultEnum;
 import cc.bnblogs.pojo.Article;
 import cc.bnblogs.pojo.Category;
@@ -99,10 +101,13 @@ public class IndexController {
     @GetMapping("/tag/{id}.html")
     public String tagList(@PathVariable Integer id,
                                @RequestParam(required = false,defaultValue = "1") Integer pageNumber,
-                               Model model){
+                               Model model) throws CustomException {
         Tag tag = tagService.detail(id);
+        if (Objects.isNull(tag)) {
+            throw new CustomException();
+        }
         model.addAttribute("tag",tag);
-        // todo id不存在时要特殊处理
+
         ArticleSearch articleSearch = ArticleSearch.indexSearch(pageNumber,5);
         articleSearch.setTid(id);
         PageHelper<Article> articlePage = articleService.search(articleSearch);
@@ -123,10 +128,12 @@ public class IndexController {
     @GetMapping("/category/{id}.html")
     public String categoryList(@PathVariable Integer id,
                                @RequestParam(required = false,defaultValue = "1") Integer pageNumber,
-                               Model model){
+                               Model model) throws CustomException {
         Category category = categoryService.detail(id);
+        if (Objects.isNull(category)) {
+            throw new CustomException();
+        }
         model.addAttribute("category",category);
-        // todo 分类不存在时要特殊处理
         ArticleSearch articleSearch = ArticleSearch.indexSearch(pageNumber,5);
         articleSearch.setCid(id);
         PageHelper<Article> articlePage = articleService.search(articleSearch);
@@ -178,22 +185,54 @@ public class IndexController {
         return "tags";
     }
 
-    @GetMapping("/error")
-    public String error() {
-        return "error";
+    /**
+     * 404错误请求
+     * @param model MVC model
+     * @return 错误页
+     */
+    @GetMapping("/error/404.html")
+    public String error404(Model model) {
+        model.addAttribute("error", ErrorCodeEnum.ERROR_404);
+        return "fail";
+    }
+
+    /**
+     * 500错误请求
+     * @param model MVC model
+     * @return 错误页
+     */
+    @GetMapping("/error/500.html")
+    public String error500(Model model) {
+        model.addAttribute("error", ErrorCodeEnum.ERROR_500);
+        return "fail";
     }
 
+    /**
+     * 文章详情页
+     * @param id 文章id
+     * @param model MVC model
+     * @param request HttpServletRequest请求
+     * @param response HttpServletResponse响应
+     * @return
+     */
+
     @GetMapping("/{id}.html")
     public String detail(@PathVariable Integer id, Model model,
-                         HttpServletRequest request, HttpServletResponse response) {
+                         HttpServletRequest request, HttpServletResponse response)
+            throws CustomException {
         Article article = articleService.detail(id);
+        // 文章不存在
+        if (Objects.isNull(article)) {
+            throw new CustomException();
+        }
+
         // 如果cookie不存在
         if (Objects.isNull(CookieUtil.getCookie(request,Article.VIEW_PREFIX + id))) {
             // 更新文章浏览量
             articleService.viewArticle(id);
             CookieUtil.setCookie(response,Article.VIEW_PREFIX + id,"true");
         }
-        // todo 文章内容不存在时应该抛出异常
+
         model.addAttribute("article",article);
         PageHelper<Comment> commentPage = commentService.show(id,1);
         // 返回第一页评论

src/main/java/cc/bnblogs/enums/ErrorCodeEnum.java

@@ -0,0 +1,20 @@
+package cc.bnblogs.enums;
+
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+
+
+/**
+ * @author zfp@bnblogs.cc
+ * @createTime: 2022/10/22
+ */
+
+@Getter
+@AllArgsConstructor
+public enum ErrorCodeEnum {
+    // HTTP请求的状态码和返回信息
+    ERROR_404(404,"对不起，你请求的页面暂时未找到.<br>它或许已经被迁移至其它页面啦."),
+    ERROR_500(500,"您好，服务器暂时出发问题，请稍候访问.<br>或您也可以尝试联系站长."),;
+    private final Integer code;
+    private final String msg;
+}

src/main/resources/static/css/error.css

@@ -247,7 +247,9 @@ sup {
   display: block;
   top: 3rem;
   left: 3rem;
-  width: 5rem;
+  width: 20rem;
+  font-weight: 500;
+  font-size: larger;
 }
 .logo-link .logo {
   width: 100%;

src/main/resources/templates/fail.html

@@ -1,5 +1,5 @@
 <!DOCTYPE html>
-<html lang="en">
+<html xmlns:th="http://www.thymeleaf.org" xmlns="http://www.w3.org/1999/html" lang="en">
 <head>
     <meta charset="utf-8">
     <title>Title</title>
@@ -13,7 +13,7 @@
 <body class="flat">
 <div id="particles-js"></div>
 
-<a href="/" class="logo-link" title="返回首页" >冷文学习者</a>
+<a th:href="@{/}" class="logo-link" title="返回首页" ><th:block th:text="${@webSite.title}"></th:block></a>
 
 <div class="content">
 
@@ -47,10 +47,9 @@
         </div>
 
         <!-- Your text -->
-        <h1>错误码：404</h1>
+        <h1>错误码：<th:block th:text="${error.getCode()}"></th:block> </h1>
 
-        <p>对不起，你请求的页面暂时未找到.<br>
-            它或许已经被迁移至其它页面啦.</p>
+        <p th:utext="${error.getMsg()}"></p>
 
     </div>
 
@@ -59,7 +58,7 @@
 <footer>
 
     <ul>
-        <li><a href="/">首页</a></li>
+        <li><a th:href="@{/}">首页</a></li>
 
         <li><a href="javascript:window.history.back()">返回上一级</a></li>
     </ul>