全局异常处理

Posted 2020-08-28

全局异常处理

package yycg.base.process.exception;

import java.io.IOException;

import java.lang.reflect.Method;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import org.springframework.core.annotation.AnnotationUtils;

import org.springframework.http.HttpOutputMessage;

import org.springframework.http.MediaType;

import org.springframework.http.converter.HttpMessageConverter;

import org.springframework.http.converter.HttpMessageNotWritableException;

import org.springframework.http.server.ServletServerHttpResponse;

import org.springframework.web.bind.annotation.ResponseBody;

import org.springframework.web.method.HandlerMethod;

import org.springframework.web.servlet.HandlerExceptionResolver;

import org.springframework.web.servlet.ModelAndView;

import yycg.base.process.result.ExceptionResultInfo;

import yycg.base.process.result.ResultInfo;

/**

 * 全局异常处理器

 * @author Administrator

 *

 */

public class ExceptionResolverCustom implements HandlerExceptionResolver {

  // json转换器

// 将异常信息转json

private HttpMessageConverter<ExceptionResultInfo> jsonMessageConverter;

// 前端控制器调用此方法执行异常处理

// handler，执行的action类就包装了一个方法（对应url的方法）

@Override

public ModelAndView resolveException(HttpServletRequest request,

HttpServletResponse response, Object handler, Exception ex) {

// 输出 异常信息

ex.printStackTrace();

// 转成springmvc底层对象（就是对action方法的封装对象，只有一个方法）

HandlerMethod handlerMethod = (HandlerMethod) handler;

// 取出方法

Method method = handlerMethod.getMethod();

// 判断方法是否返回json

// 只要方法上有responsebody注解表示返回json

// 查询method是否有responsebody注解

ResponseBody responseBody = AnnotationUtils.findAnnotation(method,

ResponseBody.class);

if (responseBody != null) {

// 将异常信息转json输出

return this.resolveJsonException(request, response, handlerMethod,

ex);

}

// 这里说明action返回的是jsp页面

// 解析异常

ExceptionResultInfo exceptionResultInfo = resolveExceptionCustom(ex);

// 将异常信息在异常页面显示

request.setAttribute("exceptionResultInfo",

exceptionResultInfo.getResultInfo());

// 转向错误页面

ModelAndView modelAndView = new ModelAndView();

modelAndView.addObject("exceptionResultInfo",

exceptionResultInfo.getResultInfo());

modelAndView.setViewName("/base/error");// 逻辑视图名

return modelAndView;

}

// 异常信息解析方法

private ExceptionResultInfo resolveExceptionCustom(Exception ex) {

ResultInfo resultInfo = null;

if (ex instanceof ExceptionResultInfo) {

// 抛出的是系统自定义异常

resultInfo = ((ExceptionResultInfo) ex).getResultInfo();

} else {

// 重新构造“未知错误”异常

resultInfo = new ResultInfo();

resultInfo.setType(ResultInfo.TYPE_RESULT_FAIL);

resultInfo.setMessage("未知错误！");

}

return new ExceptionResultInfo(resultInfo);

}

// 将异常信息转json输出

private ModelAndView resolveJsonException(HttpServletRequest request,

HttpServletResponse response, Object handler, Exception ex) {

// 解析异常

ExceptionResultInfo exceptionResultInfo = resolveExceptionCustom(ex);

HttpOutputMessage outputMessage = new ServletServerHttpResponse(response);

try {

//将exceptionResultInfo对象转成json输出

jsonMessageConverter.write(exceptionResultInfo, MediaType.APPLICATION_JSON, outputMessage);

} catch (HttpMessageNotWritableException e) {

// TODO Auto-generated catch block

e.printStackTrace();

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

return new ModelAndView();

}

public HttpMessageConverter<ExceptionResultInfo> getJsonMessageConverter() {

return jsonMessageConverter;

}

public void setJsonMessageConverter(

HttpMessageConverter<ExceptionResultInfo> jsonMessageConverter) {

this.jsonMessageConverter = jsonMessageConverter;

}

    

}