SpringBoot2 全局异常处理

参考这篇文章里面的几种异常形式：

全局异常处理是个比较重要的功能，一般在项目里都会用到。 
大概把一次请求分成三个阶段，来分别进行全局的异常处理。 
一：在进入Controller之前，譬如请求一个不存在的地址，404错误。 
二：在执行@RequestMapping时，进入逻辑处理阶段前。譬如传的参数类型错误。 
三：以上都正常时，在controller里执行逻辑代码时出的异常。譬如NullPointerException。 
http://blog.csdn.net/tianyaleixiaowu/article/details/70145251

直接将编写的全局异常处理类放入项目中，配置@Controller将类载入spring中即可使用，不需要任何配置。

以下是我写的异常处理类：

1package com.archibladwitwicke.springboot2.chapter03.controller;
2
3import com.fasterxml.jackson.databind.ObjectMapper;
4import org.apache.commons.logging.Log;
5import org.apache.commons.logging.LogFactory;
6import org.springframework.beans.factory.annotation.Autowired;
7import org.springframework.boot.autoconfigure.web.servlet.error.AbstractErrorController;
8import org.springframework.boot.web.servlet.error.DefaultErrorAttributes;
9import org.springframework.stereotype.Controller;
10import org.springframework.web.bind.annotation.RequestMapping;
11import org.springframework.web.servlet.ModelAndView;
12
13import javax.servlet.ServletException;
14import javax.servlet.http.HttpServletRequest;
15import javax.servlet.http.HttpServletResponse;
16import java.io.IOException;
17import java.util.Collections;
18import java.util.HashMap;
19import java.util.Map;
20
21@Controller
22public class GlobalErrorController extends AbstractErrorController {
23    private static final String ERROR_PATH = "/error";
24    private Log log = LogFactory.getLog(GlobalErrorController.class);
25
26    @Autowired
27    ObjectMapper objectMapper;
28
29    public GlobalErrorController() {
30        super(new DefaultErrorAttributes());
31    }
32
33    @RequestMapping(ERROR_PATH)
34    public ModelAndView getErrorPath(HttpServletRequest request, HttpServletResponse response) {
35        Map<String, Object> model = Collections.unmodifiableMap(getErrorAttributes(
36                request, false));
37        Throwable cause = getCause(request);
38        int status = (Integer) model.get("status");
39        //错误信息
40        String message = (String) model.get("message");
41        //友好提示
42        String errorMessage = getErrorMessage(cause);
43
44        String requestPath = (String) model.get("path");
45
46
47        //后台打印日志信息方方便查错
48        log.info(status + ":" + message, cause);
49        log.info("requestPath---" + ":" + requestPath);
50
51        //后台打印日志信息方方便查错
52        log.info(message, cause);
53        response.setStatus(status);
54        if (!isJsonRequest(request, model)) {
55            ModelAndView view = new ModelAndView("/error.btl");
56            view.addAllObjects(model);
57            view.addObject("status", status);
58            view.addObject("errorMessage", errorMessage);
59            view.addObject("cause", cause);
60            return view;
61
62        } else {
63            Map<String, Object> error = new HashMap<>();
64            error.put("success", false);
65            error.put("errorMessage", getErrorMessage(cause));
66            error.put("message", message);
67            writeJson(response, error);
68            return null;
69        }
70
71
72    }
73
74    private boolean isJsonRequest(HttpServletRequest request, Map<String, Object> model) {
75        // 修复bug，在此类中，使用request无法获取requestPath
76        String requestPath = (String) model.get("path");
77        if (requestPath.endsWith(".json")) {
78            return true;
79        } else {
80            return (request.getHeader("accept").contains("application/json") || (request.getHeader("X-Requested-With") != null
81                    && request.getHeader("X-Requested-With").contains("XMLHttpRequest")));
82        }
83    }
84
85    private void writeJson(HttpServletResponse response, Map<?, ?> error) {
86        response.setContentType("application/json;charset=utf-8");
87        try {
88            response.getWriter().write(objectMapper.writeValueAsString(error));
89        } catch (IOException e) {
90            e.printStackTrace();
91        }
92    }
93
94    private String getErrorMessage(Throwable ex) {
95        /*不给前端显示详细错误*/
96        return "服务器错误,请联系管理员";
97    }
98
99    private Throwable getCause(HttpServletRequest request) {
100        Throwable error = (Throwable) request.getAttribute("javax.servlet.error.exception");
101        if (error != null) {
102            while (error instanceof ServletException && error.getCause() != null) {
103                error = ((ServletException) error).getCause();
104            }
105        }
106        return error;
107    }
108
109    @Override
110    public String getErrorPath() {
111        return ERROR_PATH;
112    }
113}

可以根据项目具体修改这个方法，将判断ajax请求的种类进行完善，其余的部分可以不用修改：

1private boolean isJsonRequest(HttpServletRequest request, Map<String, Object> model) {
2        // 修复bug，在此类中，使用request无法获取requestPath
3        String requestPath = (String) model.get("path");
4        if (requestPath.endsWith(".json")) {
5            return true;
6        } else {
7            return (request.getHeader("accept").contains("application/json") || (request.getHeader("X-Requested-With") != null
8                    && request.getHeader("X-Requested-With").contains("XMLHttpRequest")));
9        }
10    }

此异常类可以对上述三种异常情况进行拦截处理，显示自定义的异常处理页面或异常处理数据。