springboot全局异常处理

基于springboot的全局异常处理 

1 编写ResultBuilder类

package com.test.domi.common.utils;

import org.apache.commons.lang.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.boot.autoconfigure.web.ErrorProperties;
import org.springframework.boot.autoconfigure.web.ServerProperties;
import org.springframework.core.Ordered;
import org.springframework.http.HttpStatus;
import org.springframework.validation.BindingResult;
import org.springframework.validation.FieldError;
import org.springframework.web.bind.MethodArgumentNotValidException;
import org.springframework.web.servlet.HandlerExceptionResolver;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.util.List;

public class ResultBuilder implements HandlerExceptionResolver,Ordered {

    private static final Logger LOGGER = LoggerFactory.getLogger(ResultBuilder.class);
    private static final String ERROR_NAME = "fp.error";
    private ErrorProperties errorProperties;

    public ErrorProperties getErrorProperties() {
        return errorProperties;
    }

    public ResultBuilder(ServerProperties serverProperties){
        LOGGER.info("serverProperties:{}",serverProperties.getError());
        this.errorProperties = serverProperties.getError();
    }

    public ResultInfo getErrorInfo(HttpServletRequest request){
        return  this.getErrorInfo(request,this.getError(request));
    }

    /**
     * 全局异常返回处理
     * @param request
     * @param error
     * @return
     */
    public ResultInfo getErrorInfo(HttpServletRequest request,Throwable error){
          ResultInfo resultInfo = new ResultInfo();
          //根据不同的error获取错误信息
          String resultCode = "";
          StringBuffer msg = new StringBuffer();
          if (error instanceof MethodArgumentNotValidException) {
              //1 参数校验异常
              resultCode = getString2((MethodArgumentNotValidException) error, resultCode, msg);
          }else {
              //3 httpStatu枚举code对应的异常
              resultCode = getString3(request, msg);
          }
          resultInfo.setCode(resultCode);
          resultInfo.setMessage(msg.toString());
          resultInfo.setData((Object)null);
          return resultInfo;
    }

    private String getString3(HttpServletRequest request, StringBuffer msg) {
        msg.append(this.getHttpStatus(request).getReasonPhrase());
        return String.valueOf(this.getHttpStatus(request).value());
    }

    private String getString2(MethodArgumentNotValidException error, String resultCode, StringBuffer msg) {
        BindingResult bindingResult = error.getBindingResult();
        if (bindingResult.hasErrors()) {
            List<FieldError> list = bindingResult.getFieldErrors();
            resultCode =ResultCode.CONNECT_ERROR.getCode();
            for (FieldError fieldError : list) {
                msg.append(fieldError.getDefaultMessage() + ";");
            }
        }
        return resultCode;
    }

    private String getString(Throwable error, StringBuffer msg) {
        msg.append(error.getMessage());
        return ResultCode.INSERT_ERROR.getCode();
    }

    /**
     *  拿到最根部的error,携带手动抛出的异常信息
     * @param request
     * @return
     */
    public Throwable getError(HttpServletRequest request){
        Throwable error = (Throwable)request.getAttribute(ERROR_NAME);
        if (error == null) {
            error = (Throwable)request.getAttribute("javax.servlet.error.exception");
        }

        if (error != null) {
            //while (error instanceof ServletException && ((Throwable) error).getCause() != null) {
            while (error instanceof Exception && ((Throwable) error).getCause() != null) {
                error = ((Throwable) error).getCause();
            }
        } else {
            String message = (String)request.getAttribute("javax.servlet.error.message");
            if (StringUtils.isNotEmpty(message)) {
                HttpStatus status = this.getHttpStatus(request);
                message = "Unknown Exception With" + status.value() + " " + status.getReasonPhrase();
            }

            error = new Exception(message);
        }

        return (Throwable)error;
    }

    public HttpStatus getHttpStatus(HttpServletRequest request){
        Integer statusCode = (Integer)request.getAttribute("javax.servlet.error.status_code");
        try {
            return statusCode != null ? HttpStatus.valueOf(statusCode.intValue()) : HttpStatus.INTERNAL_SERVER_ERROR;
        } catch (Exception var4) {
            return HttpStatus.INTERNAL_SERVER_ERROR;
        }
    }

    @Override
    public int getOrder() {
        return 0;
    }

    @Override
    public ModelAndView resolveException(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) {
        httpServletRequest.setAttribute(ERROR_NAME, e);
        return null;
    }
}

2 编写ExceptionConfig类（传入ServerProperties ，实例化ResultBuilder。springboot中ErrorProperties类定义了异常自动映射路径@Value("${error.path:/error}")private String path = "/error"）

package com.test.domi.config;

import com.test.domi.common.system.ResultBuilder;
import org.springframework.boot.autoconfigure.web.ServerProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.Ordered;
import org.springframework.core.annotation.Order;
import javax.annotation.Resource;

@Configuration
@Order(Ordered.HIGHEST_PRECEDENCE)
public class ExceptionConfig {
    @Resource
    private ServerProperties serverProperties;
    @Bean
    public ResultBuilder resultBuilder(){
        return  new ResultBuilder(serverProperties);
    }
}

ErrorProperties：

//
// Source code recreated from a .class file by IntelliJ IDEA
// (powered by Fernflower decompiler)
//

package org.springframework.boot.autoconfigure.web;

import org.springframework.beans.factory.annotation.Value;

public class ErrorProperties {
    @Value("${error.path:/error}")
    private String path = "/error";
    private ErrorProperties.IncludeStacktrace includeStacktrace;

    public ErrorProperties() {
        this.includeStacktrace = ErrorProperties.IncludeStacktrace.NEVER;
    }

    public String getPath() {
        return this.path;
    }

    public void setPath(String path) {
        this.path = path;
    }

    public ErrorProperties.IncludeStacktrace getIncludeStacktrace() {
        return this.includeStacktrace;
    }

    public void setIncludeStacktrace(ErrorProperties.IncludeStacktrace includeStacktrace) {
        this.includeStacktrace = includeStacktrace;
    }

    public static enum IncludeStacktrace {
        NEVER,
        ALWAYS,
        ON_TRACE_PARAM;

        private IncludeStacktrace() {
        }
    }
}

3 定义全局 异常Controller接管所有抛出的异常

package spring.cloud.common.controller;

import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.autoconfigure.web.servlet.error.BasicErrorController;
import org.springframework.boot.web.servlet.error.ErrorController;
import org.springframework.http.MediaType;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.servlet.ModelAndView;
import spring.cloud.common.util.ResultBuilder;
import spring.cloud.common.util.ResultInfo;
import javax.annotation.Resource;
import javax.servlet.http.HttpServletRequest;


@RestController
@RequestMapping("/error")
public class GlobalErrorController implements ErrorController{

    /**
     * 1 ErrorController 接口的默认实现类是abstract：AbstractErrorController
     * 2 AbstractErrorController 的子类 BasicErrorController 才是真正干活儿的实现类（分html、json 两个方法处理，我们只需要在GlobalErrorController重写这2个方法即可）
     * 3 BasicErrorController 有 private final ErrorProperties errorProperties;属性
     * ErrorProperties里面记录了error的路径：
     * @Value("${error.path:/error}")
     * private String path = "/error";
     * -----
     * 4 BasicErrorController 的封装只能将状态码的提示信息返回前台，不能拿到手动抛异常的信息，因此需要实现HandlerExceptionResolver
     *  ------------------------------------------------------------
     *  BasicErrorController只有有参构造，无法直接继承
     *  如果不实现ErrorController，则会造成相同路径/error有2个类，冲突了。启动时报如下异常：
     *  org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'requestMappingHandlerMapping' defined in class path resource [org/springframework/web/servlet/config/annotation/DelegatingWebMvcConfiguration.class]: Invocation of init method failed; nested exception is java.lang.IllegalStateException: Ambiguous mapping. Cannot map 'basicErrorController' method
     * public org.springframework.web.servlet.ModelAndView org.springframework.boot.autoconfigure.web.servlet.error.BasicErrorController.errorHtml(javax.servlet.http.HttpServletRequest,javax.servlet.http.HttpServletResponse)
     * to {[/error],produces=[text/html]}: There is already 'globalErrorController' bean method
     */
    private final static String DEFAULT_ERROR_VIEW = "/error";
    private final static  org.slf4j.Logger LOGGER = LoggerFactory.getLogger(GlobalErrorController.class);
    /**
     * ResultBuilder 实现 HandlerExceptionResolver 接口重写public ModelAndView resolveException(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e)
     * 通过httpServletRequest.setAttribute("fp.error", e);将Exception放到request中
     * 这种方法的好处是能拿到手动抛异常的信息
     */
    @Resource
    private ResultBuilder resultBuilder;

    /** 1- BasicErrorController只有有参构造，无法直接继承,
     *  2- 如果不实现ErrorController，则会造成相同路径/error有2个类，冲突了。启动时报如下异常：
     *  org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'requestMappingHandlerMapping' defined in class path resource [org/springframework/web/servlet/config/annotation/DelegatingWebMvcConfiguration.class]: Invocation of init method failed; nested exception is java.lang.IllegalStateException: Ambiguous mapping. Cannot map 'basicErrorController' method
     * public org.springframework.web.servlet.ModelAndView org.springframework.boot.autoconfigure.web.servlet.error.BasicErrorController.errorHtml(javax.servlet.http.HttpServletRequest,javax.servlet.http.HttpServletResponse)
     * to {[/error],produces=[text/html]}: There is already 'globalErrorController' bean method
     * ----------------------
     * ErrorProperties里面记录了error的路径：
     * * @Value("${error.path:/error}")
     * * private String path = "/error";
     * 如果不需要从GlobalErrorController中的getErrorPath方法获取该路径，则该方法可以空实现
     */
    @Override
    public String getErrorPath(){
//        return null;
        return  resultBuilder.getErrorProperties().getPath();
    }

    /**
     * 如果请求头返回的类型是text/html，则返回到错误信息页面
     * @param request
     * @return
     */
    @RequestMapping(produces = MediaType.TEXT_HTML_VALUE)
    public ModelAndView errorHtml(HttpServletRequest request) {
        return new ModelAndView(DEFAULT_ERROR_VIEW,"errorInfo",resultBuilder.getErrorInfo(request));
    }

    /**
     * 除了text/html的请求头信息，其它都返回json格式
     * @param request 请求对象
     * @return 错误信息字符串
     */
    @RequestMapping(produces = {MediaType.APPLICATION_JSON_VALUE})
    public ResultInfo error(HttpServletRequest request){
        return resultBuilder.getErrorInfo(request);
    }



}

配置完毕，后台的未被捕获的异常将从dao层到dervice层到controller层，然后被全局异常controller统一接管，封装之后返回给前台！