ajax和普通请求使用spring mvc在controller中的异常统一处理
（1）建共用的异常处理器 CustomExceptionResolver
package
com.ggs.mstd.controller;
import
javax.servlet.http.HttpServletRequest;
import
javax.servlet.http.HttpServletResponse;
import
org.apache.ibatis.ognl.OgnlException;
import
org.springframework.stereotype.Controller;
import
org.springframework.web.bind.annotation.ExceptionHandler;
import
org.springframework.web.bind.annotation.ResponseBody;
import
org.springframework.web.servlet.ModelAndView;
import
com.ggs.mstd.CustomException.CustomException;
import
com.ggs.mstd.CustomException.RequestUtil;
import
com.ggs.mstd.CustomException.ResponseData;
@Controller
public
class
CustomExceptionResolver {
/**
@author
wenfei.fang@hand
-
china.com
* 处理控制层所有异常.
*
@param
exception 未捕获的异常
*
@param
request HttpServletRequest
*
@return
ResponseData(BaseException 被处理) 或者 ModelAndView(其他 Exception ,500错误)
*/
@ExceptionHandler
(value = { Exception.
class
})
public
@ResponseBody
Object exceptionHandler(Exception
exception
, HttpServletRequest
request
, HttpServletResponse
response
) {
/*判断请求类型是不是ajax的*/
if
(RequestUtil.isAjaxRequest(
request
)) {
/*如果是Ajax请求将错误信息返回到ajax date*/
Throwable
thr
= getRootCause(
exception
);
ResponseData
res
=
new
ResponseData();
if
(
thr
instanceof
CustomException) {
/*如果自定义的错误显示自定义的错误类型*/
CustomException
be
= (CustomException)
thr
;
res
.findMessage(
be
.getCode());
res
.setCode(
be
.getCode());
res
.setMessage(
be
.getMessage());
}
else
{
/*如果不是自定义的错误显示系统性错误或同一错误*/
res
.findMessage(ResponseData.
SYSTEM_EXCEPTION
);
res
.setMessage(
thr
.getMessage());
}
return
res
;
}
else
{
/*如果不是Ajax的重从定向到错误界面*/
return
new
ModelAndView(
"redirect:/categoryAttribute"
);
}
}
private
Throwable getRootCause(Throwable
throwable
) {
while
(
throwable
.getCause() !=
null
) {
throwable
=
throwable
.getCause();
}
if
(
throwable
instanceof
OgnlException && ((OgnlException)
throwable
).getReason() !=
null
) {
return
getRootCause(((OgnlException)
throwable
).getReason());
}
return
throwable
;
}
}
（2）建立一个终态的类RequestUtil 判断请求类型
package
com.ggs.mstd.CustomException;
import
javax.servlet.http.Cookie;
import
javax.servlet.http.HttpServletRequest;
/**
*
@author
wenfei.fang
*
* 2016年11月11日
*/
public
final
class
RequestUtil {
public
static
final
String
X_REQUESTED_WIDTH
=
"X-Requested-With"
;
public
static
final
String
XML_HTTP_REQUEST
=
"XMLHttpRequest"
;
private
RequestUtil() {
}
/**
* 判断是否ajax请求.
* 可以看到Ajax 请求多了个 x
-
requested
-
with ，可以利用它，
* request.getHeader("x
-
requested
-
with"); 为 null，则为传统同步请求，为 XMLHttpRequest，则为Ajax 异步请求。
*
@param
request HttpServletRequest
*
@return
是否ajax请求.
*/
public
static
boolean
isAjaxRequest(HttpServletRequest
request
) {
String
xr
=
request
.getHeader(
X_REQUESTED_WIDTH
);
return
(
xr
!=
null
&&
XML_HTTP_REQUEST
.equalsIgnoreCase(
xr
));
}
public
static
String getCookieValue(HttpServletRequest
request
, String
name
) {
Cookie[]
cookies
=
request
.getCookies();
if
(
cookies
!=
null
) {
for
(Cookie
cookie
:
cookies
) {
String
cookieName
=
cookie
.getName();
if
(
cookieName
.equals(
name
)) {
return
cookie
.getValue();
}
}
}
return
null
;
}
}
（3）建立一个类 继承 Exception
public
abstract
class
CustomException
extends
Exception {
private
static
final
long
serialVersionUID
= 1L;
// e.g. ORDER_FROZEN
private
String
code
;
private
String
descriptionKey
;
private
Object[]
parameters
;
/**
* 不应该直接实例化,应该定义子类.
*
*
@param
code
* 异常 code,通常与模块 CODE 对应
*
@param
descriptionKey
* 异常消息代码,系统描述中定义
*
@param
parameters
* 如果没有参数,可以传 null
*/
protected
CustomException(String
code
, String
descriptionKey
, Object[]
parameters
) {
super
(
descriptionKey
);
this
.
code
=
code
;
this
.
descriptionKey
=
descriptionKey
;
this
.
parameters
=
parameters
;
}
public
String getCode() {
return
code
;
}
public
String getDescriptionKey() {
return
descriptionKey
;
}
public
Object[] getParameters() {
return
parameters
;
}
public
void
setCode(String
code
) {
this
.
code
=
code
;
}
public
void
setDescriptionKey(String
descriptionKey
) {
this
.
descriptionKey
=
descriptionKey
;
}
public
void
setParameters(Object[]
parameters
) {
this
.
parameters
=
parameters
;
}
}
（4）错误处理类
/**
* 数据返回对象.
*
*
@author
wenfei.fang@hand
-
china.com
*/
public
class
ResponseData{
public
static
final
String
SYSTEM_EXCEPTION
=
"Please contact the administrator."
;
public
static
final
String
MSG_ERROR_APPROVE_COMMENTS
=
"msg error approve comments"
;
public
void
findMessage(String
code
){
this
.
message
=
code
==
null
?
SYSTEM_EXCEPTION
:
code
;
}
// 返回状态编码
private
String
code
;
// 返回信息
private
String
message
;
public
String getCode() {
return
code
;
}
public
void
setCode(String
code
) {
this
.
code
=
code
;
}
public
String getMessage() {
return
message
;
}
public
void
setMessage(String
message
) {
this
.
message
=
message
;
}
}
（5）Controller继承CustomExceptionResolver错误处理
@Controller
public class MegaFileReportController extends CustomExceptionResolver{
@RequestMapping(value = "/api/megaFile/e")
public @ResponseBody String e(@RequestParam Map params) {
int m=1/0;
return null;
}
}