Java 拦截@RequestHeader异常以查找缺少的标头
例如,我在控制器中有一个带有has参数的方法Java 拦截@RequestHeader异常以查找缺少的标头,java,spring,spring-mvc,servlets,Java,Spring,Spring Mvc,Servlets,例如,我在控制器中有一个带有has参数的方法 @RequestMapping(value = "/{blabla}", method = RequestMethod.POST) @ResponseStatus(HttpStatus.CREATED) public void post(@RequestHeader("ETag") int etag) 若请求中并没有ETag头,则client gets 400(BAD_请求),这并没有任何信息。 我需要以某种方式处理这个异常,并将我自己的异常发送给
@RequestMapping(value = "/{blabla}", method = RequestMethod.POST)
@ResponseStatus(HttpStatus.CREATED)
public void post(@RequestHeader("ETag") int etag)
若请求中并没有ETag头,则client gets 400(BAD_请求),这并没有任何信息。
我需要以某种方式处理这个异常,并将我自己的异常发送给客户机(为此我使用JSON)。
我知道我可以通过@ExceptionHandler截获异常,但在这种情况下,所有HTTP 400请求都将得到处理,但我希望头中缺少ETag。
有什么想法吗?有两种方法可以实现你正在尝试的目标 首先将
@RequestHeader
与required
false
@RequestMapping(value = "/{blabla}", method = RequestMethod.POST)
@ResponseStatus(HttpStatus.CREATED)
public void post(@RequestHeader(value="ETag", required=false) String ETag) {
if(ETag == null) {
// Your JSON Error Handling
} else {
// Your Processing
}
}
第二次使用HttpServletRequest
而不是@RequestHeader
@RequestMapping(value = "/{blabla}", method = RequestMethod.POST)
@ResponseStatus(HttpStatus.CREATED)
public void post(HttpServletRequest request) {
String ETag = request.getHeader("ETag");
if(ETag == null) {
// Your JSON Error Handling
} else {
// Your Processing
}
}
如果您不想在请求映射中处理这个问题,那么可以创建一个Servlet过滤器,并在过滤器中查找ETag头。如果不存在,则抛出异常。这将仅适用于与筛选器的URL映射匹配的请求
public final class MyEtagFilter extends OncePerRequestFilter {
@Override
protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) throws ServletException, IOException {
String etag = request.getHeader("ETag");
if(etag == null)
throw new MissingEtagHeaderException("...");
filterChain.doFilter(request, response);
}
}
您必须实现自己的MissingEtagHeaderException,或使用其他一些现有的异常。您应该使用@ExceptionHandler方法,该方法查看ETag标头是否存在并采取适当的操作:
@ExceptionHandler(UnsatisfiedServletRequestParameterException.class)
public onErr400(@RequestHeader(value="ETag", required=false) String ETag,
UnsatisfiedServletRequestParameterException ex) {
if(ETag == null) {
// Ok the problem was ETag Header : give your informational message
} else {
// It is another error 400 : simply say request is incorrect or use ex
}
}
这是相对简单的。声明两个处理程序方法,一个在
@RequestMapping
headers
属性中声明适当的头,另一个不声明。Spring将根据请求的内容小心地调用相应的请求
@RequestMapping(value = "/{blabla}", method = RequestMethod.POST, headers = "ETag")
@ResponseStatus(HttpStatus.CREATED)
public void postWith(@RequestHeader("ETag") int etag) {
// has it
}
@RequestMapping(value = "/{blabla}", method = RequestMethod.POST)
@ResponseStatus(HttpStatus.CREATED)
public void postWithout() {
// no dice
// custom failure response
}
编写一个带有注释@ExceptionHandler的方法,并使用ServletRequestBindingException.class,因为在缺少标头的情况下会引发此异常 例如:
@ExceptionHandler(ServletRequestBindingException.class)
public ResponseEntity<ResponseObject> handleHeaderError(){
ResponseObject responseObject=new ResponseObject();
responseObject.setStatus(Constants.ResponseStatus.FAILURE.getStatus());
responseObject.setMessage(header_missing_message);
ResponseEntity<ResponseObject> responseEntity=new ResponseEntity<ResponseObject>(responseObject, HttpStatus.BAD_REQUEST);
return responseEntity;
}
@ExceptionHandler(ServletRequestBindingException.class)
公共响应处理错误(){
ResponseObject ResponseObject=新的ResponseObject();
responseObject.setStatus(Constants.ResponseStatus.FAILURE.getStatus());
responseObject.setMessage(标头\缺少\消息);
ResponseEntity ResponseEntity=新的ResponseEntity(responseObject,HttpStatus.BAD_请求);
返回响应性;
}
您也可以通过使用spring中的注释@ControllerAdvice
来实现这一点
@ControllerAdvice
public class ExceptionHandler extends ResponseEntityExceptionHandler{
/**
* Handle ServletRequestBindingException. Triggered when a 'required' request
* header parameter is missing.
*
* @param ex ServletRequestBindingException
* @param headers HttpHeaders
* @param status HttpStatus
* @param request WebRequest
* @return the ResponseEntity object
*/
@Override
protected ResponseEntity<Object> handleServletRequestBindingException(ServletRequestBindingException ex,
HttpHeaders headers, HttpStatus status, WebRequest request) {
return new ResponseEntity<>(ex.getMessage(), headers, status);
}
}
@ControllerAdvice
公共类ExceptionHandler扩展了ResponseEntityExceptionHandler{
/**
*处理ServletRequestBindingException。在“必需”请求时触发
*缺少标头参数。
*
*@param ex ServletRequestBindingException
*@param headers-HttpHeaders
*@param status HttpStatus
*@param request WebRequest
*@返回ResponseEntity对象
*/
@凌驾
受保护的响应handleServletRequestBindingException(ServletRequestBindingException ex,
HttpHeaders标头、HttpStatus状态、WebRequest请求){
返回新的ResponseEntity(例如getMessage()、标题、状态);
}
}
当您访问API而不使用所需的请求标头时,响应为:
字符串类型的方法参数缺少请求标头“Authorization”
与此异常类似,您可以自定义所有其他异常。您也可以拦截异常,而无需扩展
ResponseEntityExceptionHandler
:
@ControllerAdvice
public class ControllerExceptionHandler {
@ExceptionHandler(ServletRequestBindingException.class)
@ResponseBody
@ResponseStatus(HttpStatus.BAD_REQUEST)
public ResponseEntity<Object> handleServletRequestBindingException(ServletRequestBindingException ex) {
// return a ResponseEntity<Object> object here.
}
}
@RestControllerAdvice
public class ValidationHandler extends ResponseEntityExceptionHandler {
@ExceptionHandler(value = {
MissingRequestHeaderException.class,
InvalidRequestHeaderException.class
})
protected ResponseEntity<Object> handleRequestHeaderException(Exception ex) {
log.error(ex.getMessage());
return ResponseEntity.badRequest().body(ErrorResponse.builder()
.status(String.valueOf(HttpStatus.BAD_REQUEST.value()))
.reason(ex.getMessage()).build());
}
@AllArgsConstructor
@Getter
@Builder
public static class ErrorResponse {
private String status;
private String reason;
}
}
@ControllerAdvice
公共类ControllerExceptionHandler{
@ExceptionHandler(ServletRequestBindingException.class)
@应答器
@ResponseStatus(HttpStatus.BAD_请求)
公共响应性handleServletRequestBindingException(ServletRequestBindingException ex){
//在此处返回ResponseEntity对象。
}
}
如果Spring版本为5+,则需要处理的确切异常是MissingRequestHeaderException
。如果全局异常处理程序类扩展了ResponseEntityExceptionHandler
,那么为ServletRequestBindingException
添加@ExceptionHandler
将无法工作,因为MissingRequestHeaderException
扩展了ServletRequestBindingException
,后者在handleException
方法的ResponseEntityExceptionHandler
。如果您尝试,您将获得映射到…异常的不明确@ExceptionHandler方法。您可以将@Nullable
添加到此请求参数,如果不存在,请求仍会进入控制器,而不会抛出MissingRequestHeaderException
,您还可以添加手动验证,以便在控制器中抛出您喜欢的内容,并在ExceptionHandler中处理。您可以创建一个自定义异常类,例如,InvalidRequestHeaderException.java
。您可以在此处自定义例外消息
@ResponseStatus(HttpStatus.BAD_REQUEST)
public class InvalidRequestHeaderException extends RuntimeException {
public InvalidRequestHeaderException() {
super("Invalid request header provided.");
}
}
在控制器中,如果提供的标头无效,则可以引发异常
@RequestMapping(value = "/{blabla}", method = RequestMethod.POST)
@ResponseStatus(HttpStatus.CREATED)
public void post(@RequestHeader("ETag") int etag) {
// some code
if (!isSupportedPlatform(platform)) {
throw new InvalidRequestHeaderException();
}
// some code
}
然后可以创建ValidationHandler.java来处理这些异常
@RestControllerAdvice
public class ValidationHandler extends ResponseEntityExceptionHandler {
@ExceptionHandler(value = {
MissingRequestHeaderException.class,
InvalidRequestHeaderException.class
})
protected ResponseEntity<Object> handleRequestHeaderException(Exception ex) {
log.error(ex.getMessage());
return ResponseEntity.badRequest().body(ErrorResponse.builder()
.status(String.valueOf(HttpStatus.BAD_REQUEST.value()))
.reason(ex.getMessage()).build());
}
@AllArgsConstructor
@Getter
@Builder
public static class ErrorResponse {
private String status;
private String reason;
}
}
@RestControllerAdvice
公共类ValidationHandler扩展了ResponseEntityExceptionHandler{
@ExceptionHandler(值={
MissingRequestHeaderException.class,
InvalidRequestHeaderException.class无效
})
受保护的响应HandlerRequestHeaderException(异常ex){
log.error(例如getMessage());
返回ResponseEntity.badRequest().body(ErrorResponse.builder())
.status(String.valueOf(HttpStatus.BAD_REQUEST.value()))
.reason(例如getMessage()).build());
}
@AllArgsConstructor
@吸气剂
@建筑商
公共静态类错误响应{
私有字符串状态;
私有字符串原因;
}
}
通过使用MissingRequestHeaderException
,如果您用@RequestHeader
注释的内容丢失,它将引发异常,因此您将得到如下异常:
int类型的方法参数缺少请求标头“Etag”
当请求标头存在但无效时,将引发此异常:
提供的请求标头无效
在Spring5+中,就这么简单<代码>错误响应