目錄
一、攔截器對于參數的驗證問題
二、嘗試方案之使用攔截器
三、使用spring的注解 @ControllerAdvice
一:攔截器對于參數的驗證問題
問題場景：
由于之前的參數驗證都是放在參數體里面,沒有放到方法參數上或者頭部，請求數據參數格式為json所以對于所有的接口，我需要驗證這公共部分的正確與否，所以我現在需要對請求到controller之前進行攔截，并進行這部分公共參數的驗證,所以本身最先想到了兩種方案時使用過濾器，要么使用攔截器，但是做的過程中得到第三種方案。具體見下
二、嘗試方案之使用攔截器
2.1先上代碼如下：
public class AuthInterceptor extends HandlerInterceptorAdapter {
private static final Logger log = Logger.getLogger(AuthInterceptor.class);
//本來時打算在這里面獲取到參數，然后對公共部分進行驗證
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
throws Exception {
String token = request.getParameter("appId");;
if(StringUtils.isblack(token)){
//使用流寫出對象，提示token不能為空;
ResultBean result = new ResultBean("10001","token不能為空")
...
return false;
}
//注釋一
/*
StringBuffer sb = new StringBuffer();
InputStreamReader isr = new InputStreamReader(request.getInputStream());
BufferedReader br = new BufferedReader(isr);
String s = "";
while ((s = br.readLine()) != null) {
sb.append(s);
}
System.out.println(sb.toString());
*/
//注釋二
/*
if(handler instanceof HandlerMethod){
HandlerMethod handlerMethod = (HandlerMethod)handler;
MethodParameter[] methodParameters = handlerMethod.getMethodParameters();
for(MethodParameter methodParameter : methodParameters){
System.out.println(methodParameter.getParameterName());
}
}
}
*/
xml中配置如下：
<mvc:interceptors>
<mvc:interceptor>
<mvc:mapping path="/*.cgi"/>
<mvc:mapping path="/test/*.cgi"/>
<bean class="com.mouse.moon.common.auth.AuthInterceptor"></bean>
</mvc:interceptor>
</mvc:interceptors>
上述代碼部分，可以看出，我在preHandle(...) 方法中想獲取參數，然后
在這里面做統一的驗證，成功則繼續望下走,失敗則直接以流的形式寫出
錯誤對象。在前面的問題中已經說明，參數是以json的格式傳入到后臺，
并且功能部分都是放在json的數據中，所以這里request獲取到的數據為
空數據。
2.2 :看到注釋一中的代碼,我在這里使用流的形式來讀取到請求數據,然后此時我獲取到相關的參數，可是當我繼續往下走時,請求到達controller卻報錯，錯誤的意思大致就是說流沒了,因為我們在攔截器里面讀取了流，所以在controller中沒辦法再次讀取流了，使得其直接拋出異常。異常如下：
org.springframework.http.converter.HttpMessageNotReadableException: Required request body is missing: public com.mouse.moon.common.bean.ResultBean com.mouse.person.controller.PersonController.getPersonInfo(com.mouse.moon.common.bean.ParameBean) throws com.mouse.moon.common.exception.ExceptionAbstract
at org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.readWithMessageConverters(RequestResponseBodyMethodProcessor.java:151)
at org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.resolveArgument(RequestResponseBodyMethodProcessor.java:125)
at org.springframework.web.method.support.HandlerMethodArgumentResolverComposite.resolveArgument(HandlerMethodArgumentResolverComposite.java:78)
at org.springframework.web.method.support.InvocableHandlerMethod.getMethodArgumentValues(InvocableHandlerMethod.java:162)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:129)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:110)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:814)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:737)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:959)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:893)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:646)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:121)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:504)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:421)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1074)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:611)
at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.doRun(AprEndpoint.java:2466)
at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:2455)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
主要是“Failed to read HTTP message: org.springframework.http.converter.HttpMessageNotReadableException: Required request body is missing:”
所以我就在想，那么此時我們既然讀到了流，然后再把流寫出不就可以了，可是我查閱了下資料，發現攔截器沒辦法進行這操作，倒是過濾器時可以獲取到流后再寫回去。
然后我又試驗了網上說的使用注釋二的代碼進行參數獲取，結果獲取的參數都是空的。
所以至此，使用攔截器來做參數驗證這一步基本上宣告失敗了，必須得另外處理方式，所以打算使用過濾器，但是再解決的過錯中跟朋友交流了下，說到有這么一個注解 @ControllerAdvice結合HttpEntity<String> 來使用，我就轉門去看了下，得到了我最后的解決方案，當然，過濾器的查到的資料可以試試
https://my.oschina.net/vernon/blog/363693?fromerr=2jheR52d
三、使用spring的注解 @ControllerAdvice
3.1: @ControllerAdvice說明
該注解時再spring3.2之后增加的，見名大概意思是控制器增強。
@ControllerAdvice注解內部使用@ExceptionHandler、@InitBinder、@ModelAttribute注解的方法應用到所有的 @RequestMapping注解的方法。
3.2:描述
我這里使用了結合的方式使用,@ModelAttribute結合@ExceptionHandler進行結合使用，現在@ModelAttribute中進行參數獲取，然后轉換為相應的對象,獲取后對參數進行驗證，但是驗證失敗后我們要怎么處理了，這里面沒辦法返回錯誤碼呀，所以如果驗證失敗就拋出異常，然后再@ExceptionHandler中進行統一處理。驗證通過就吧獲取的參數返回即可，那么此時在controller中獲取參數需要使用@ModelAttribute進行獲取。代碼如下：
@ControllerAdvice
public class ValidateControllerAdvice {
private static final Logger log = Logger.getLogger(ValidateControllerAdvice.class);
@ModelAttribute
public ParameBean getBobyInfo(HttpEntity<String> httpEntity,HttpServletRequest request,HttpServletResponse response) throws JsonParseException, JsonMappingException, IOException, CommonValidateException {
//獲取參數
String data = httpEntity.getBody();
ObjectMapper objectMapper = new ObjectMapper();
ParamBean paramBean = data != null ? objectMapper.readValue(data, ParamBean.class) : null;
if (pb != null)
{
String secretId = paramBean.getSecretId();
String token = paramBean.getToken();
if(StringUtils.isBlank(secretId)){
throw new ValidateException( Enums.ERROR_SECRETID_NOTNULL,
"SECRETID不能為空");
}else if(StringUtils.isBlank(token)){
throw new ValidateException( Enums.ERROR_TOKEN_NOT_NULL,
"token不能為空");
}else if(validate(token)){
throw new ValidateException( Enums.ERROR_TOKEN_INVALID,
"無效的token");
}
}
return paramBean;
}
//捕獲ValidateException的異常，統一返回
@ExceptionHandler({ValidateException.class})
@ResponseBody
public ResultBean validateException(ValidateException ex){
ResultBean result = new ResultBean();
result.setResultCode(ex.getResultCode());
result.setResultMsg(ex.getResultMsg());
return result;
}
}
四:隱患
幾天后，測試發現了一個問題，就是比如我的返回數據，我想轉換時間不反回長整形，而是"yyyy-MM-dd HH:mm:ss"的形式，所以我使用jackson的配置方案如下
<mvc:annotation-driven>
<mvc:message-converters>
<bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
<property name="objectMapper">
<bean class="com.fasterxml.jackson.databind.ObjectMapper">
<property name="serializationInclusion" value="NON_NULL"/>
<property name="dateFormat">
<bean class="java.text.SimpleDateFormat">
<constructor-arg type="java.lang.String" value="yyyy-MM-dd HH:mm:ss" />
</bean>
</property>
</bean>
</property>
<property name="supportedMediaTypes">
<list>
<value>application/json;charset=UTF-8</value>
</list>
</property>
</bean>
</mvc:message-converters>
</mvc:annotation-driven>
測試得到的結果是
org.springframework.http.converter.HttpMessageNotReadableException: Could not read document: Can not deserialize instance of java.lang.String out of START_OBJECT token
at [Source: java.io.PushbackInputStream@3a4f5e0b; line: 1, column: 1]; nested exception is com.fasterxml.jackson.databind.JsonMappingException: Can not deserialize instance of java.lang.String out of START_OBJECT token
at [Source: java.io.PushbackInputStream@3a4f5e0b; line: 1, column: 1]
at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.readJavaType(AbstractJackson2HttpMessageConverter.java:224)
at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.read(AbstractJackson2HttpMessageConverter.java:208)
at org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodArgumentResolver.readWithMessageConverters(AbstractMessageConverterMethodArgumentResolver.java:197)
at org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodArgumentResolver.readWithMessageConverters(AbstractMessageConverterMethodArgumentResolver.java:141)
at org.springframework.web.servlet.mvc.method.annotation.HttpEntityMethodProcessor.resolveArgument(HttpEntityMethodProcessor.java:123)
at org.springframework.web.method.support.HandlerMethodArgumentResolverComposite.resolveArgument(HandlerMethodArgumentResolverComposite.java:78)
at org.springframework.web.method.support.InvocableHandlerMethod.getMethodArgumentValues(InvocableHandlerMethod.java:162)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:129)
at org.springframework.web.method.annotation.ModelFactory.invokeModelAttributeMethods(ModelFactory.java:136)
at org.springframework.web.method.annotation.ModelFactory.initModel(ModelFactory.java:109)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:792)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:737)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:959)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:893)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:646)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:121)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:504)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:421)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1074)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:611)
at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.doRun(AprEndpoint.java:2466)
at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:2455)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
Caused by: com.fasterxml.jackson.databind.JsonMappingException: Can not deserialize instance of java.lang.String out of START_OBJECT token
at [Source: java.io.PushbackInputStream@3a4f5e0b; line: 1, column: 1]
at com.fasterxml.jackson.databind.JsonMappingException.from(JsonMappingException.java:148)
at com.fasterxml.jackson.databind.DeserializationContext.mappingException(DeserializationContext.java:762)
at com.fasterxml.jackson.databind.deser.std.StringDeserializer.deserialize(StringDeserializer.java:59)
at com.fasterxml.jackson.databind.deser.std.StringDeserializer.deserialize(StringDeserializer.java:12)
at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:3066)
at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:2221)
at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.readJavaType(AbstractJackson2HttpMessageConverter.java:221)
... 44 more
2016-12-10 16:47:28 [ http-apr-8080-exec-6:20921 ] - [ DEBUG ] Resolving exception from handler [public com.mouse.common.bean.ResultBean com.mouse.person.controller.PersonController.getPersonInfo(com.mouse.common.bean.ParameBean)]: org.springframework.http.converter.HttpMessageNotReadableException: Could not read document: Can not deserialize instance of java.lang.String out of START_OBJECT token
at [Source: java.io.PushbackInputStream@3a4f5e0b; line: 1, column: 1]; nested exception is com.fasterxml.jackson.databind.JsonMappingException: Can not deserialize instance of java.lang.String out of START_OBJECT token
at [Source: java.io.PushbackInputStream@3a4f5e0b; line: 1, column: 1]
2016-12-10 16:47:28 [ http-apr-8080-exec-6:20921 ] - [ DEBUG ] Resolving exception from handler [public com.mouse.common.bean.ResultBean com.mouse.person.controller.PersonController.getPersonInfo(com.mouse.common.bean.ParameBean) throws com.mouse.common.exception.ExceptionAbstract]: org.springframework.http.converter.HttpMessageNotReadableException: Could not read document: Can not deserialize instance of java.lang.String out of START_OBJECT token
at [Source: java.io.PushbackInputStream@3a4f5e0b; line: 1, column: 1]; nested exception is com.fasterxml.jackson.databind.JsonMappingException: Can not deserialize instance of java.lang.String out of START_OBJECT token
at [Source: java.io.PushbackInputStream@3a4f5e0b; line: 1, column: 1]
2016-12-10 16:47:28 [ http-apr-8080-exec-6:20921 ] - [ DEBUG ] Resolving exception from handler [public com.mouse.common.bean.ResultBean com.mouse.person.controller.PersonController.getPersonInfp(com.mouse.common.bean.ParamBean)]: org.springframework.http.converter.HttpMessageNotReadableException: Could not read document: Can not deserialize instance of java.lang.String out of START_OBJECT token
at [Source: java.io.PushbackInputStream@3a4f5e0b; line: 1, column: 1]; nested exception is com.fasterxml.jackson.databind.JsonMappingException: Can not deserialize instance of java.lang.String out of START_OBJECT token
at [Source: java.io.PushbackInputStream@3a4f5e0b; line: 1, column: 1]
2016-12-10 16:47:28 [ http-apr-8080-exec-6:20921 ] - [ WARN ] Failed to read HTTP message: org.springframework.http.converter.HttpMessageNotReadableException: Could not read document: Can not deserialize instance of java.lang.String out of START_OBJECT token
at [Source: java.io.PushbackInputStream@3a4f5e0b; line: 1, column: 1]; nested exception is com.fasterxml.jackson.databind.JsonMappingException: Can not deserialize instance of java.lang.String out of START_OBJECT token
at [Source: java.io.PushbackInputStream@3a4f5e0b; line: 1, column: 1]
2016-12-10 16:47:28 [ http-apr-8080-exec-6:20921 ] - [ DEBUG ] Null ModelAndView returned to DispatcherServlet with name 'SpringMVC': assuming HandlerAdapter completed request handling
2016-12-10 16:47:28 [ http-apr-8080-exec-6:20922 ] - [ DEBUG ] Successfully completed request
想把所有的時間都轉換了，但是發現這個在我接收參數的時候都有異常。今天在某位大神的指導下發現了問題所在，我們在加了轉換器后，在發送請求的時候會講json數據使用MappingJackson2HttpMessageConverter此類進行轉換，那么到了HttpEntity時已經是對象了但是我們卻還是使用HttpEntity<String>接收
所以一直抱上面的錯誤，轉換異常。所以我們可以嘗試如下
ObjectMapper objectMapper = new ObjectMapper();
String json="{\n"+"\t\"appId":"\"123567\",\n"+"\t\"appcode":"\"sdasfa\"+"}";
objectMapper.readValue(json,String.class);
此時就會報錯如上。所以接收點需要修改為HttpEntity<ParamEngine>的寫法，接收處就不需要在轉換類型，getBody()后就是ParamEngine對象。
五：浩學習
__
__ _ ____ __| |__ _____ ___
\ \/ \/ / | \ | \\__ \ / _ \
\ /| | / Y \/ __ \( <_> )
\/\_/ |____/|___| (____ /\____/
\/ \/
走在自己的路上，遇到要遇到的人，經歷要經歷的事，這才是我們需要面對的。努力，come on!!!
公元2016年12月7號凌晨00點35分
