目录
一、拦截器对于参数的验证问题
二、尝试方案之使用拦截器
三、使用spring的注解 @ControllerAdvice

一:拦截器对于参数的验证问题

问题场景：
由于之前的参数验证都是放在参数体里面,没有放到方法参数上或者头部，请求数据参数格式为json所以对于所有的接口，我需要验证这公共部分的正确与否，所以我现在需要对请求到controller之前进行拦截，并进行这部分公共参数的验证,所以本身最先想到了两种方案时使用过滤器，要么使用拦截器，但是做的过程中得到第三种方案。具体见下

二、尝试方案之使用拦截器

2.1先上代码如下：

public class AuthInterceptor extends HandlerInterceptorAdapter {
private static final Logger log = Logger.getLogger(AuthInterceptor.class);
//本来时打算在这里面获取到参数，然后对公共部分进行验证    
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
        throws Exception {
        String token = request.getParameter("appId");;
        if(StringUtils.isblack(token)){
               //使用流写出对象，提示token不能为空;
               ResultBean result = new ResultBean("10001","token不能为空")
               ...
              return false;
          }
        //注释一
        /*
        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());
        */

        //注释二
        /*  
        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>

上述代码部分，可以看出，我在preHandle(...) 方法中想获取参数，然后
在这里面做统一的验证，成功则继续望下走,失败则直接以流的形式写出
错误对象。在前面的问题中已经说明，参数是以json的格式传入到后台，
并且功能部分都是放在json的数据中，所以这里request获取到的数据为
空数据。
2.2 :看到注释一中的代码,我在这里使用流的形式来读取到请求数据,然后此时我获取到相关的参数，可是当我继续往下走时,请求到达controller却报错，错误的意思大致就是说流没了,因为我们在拦截器里面读取了流，所以在controller中没办法再次读取流了，使得其直接抛出异常。异常如下：

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，那么此时我们既然读到了流，然后再把流写出不就可以了，可是我查阅了下资料，发现拦截器没办法进行这操作，倒是过滤器时可以获取到流后再写回去。
然后我又试验了网上说的使用注释二的代码进行参数获取，结果获取的参数都是空的。
所以至此，使用拦截器来做参数验证这一步基本上宣告失败了，必须得另外处理方式，所以打算使用过滤器，但是再解决的过错中跟朋友交流了下，说到有这么一个注解 @ControllerAdvice结合HttpEntity<String> 来使用，我就转门去看了下，得到了我最后的解决方案，当然，过滤器的查到的资料可以试试
https://my.oschina.net/vernon/blog/363693?fromerr=2jheR52d

三、使用spring的注解 @ControllerAdvice

3.1: @ControllerAdvice说明
该注解时再spring3.2之后增加的，见名大概意思是控制器增强。
@ControllerAdvice注解内部使用@ExceptionHandler、@InitBinder、@ModelAttribute注解的方法应用到所有的 @RequestMapping注解的方法。
3.2:描述
我这里使用了结合的方式使用,@ModelAttribute结合@ExceptionHandler进行结合使用，现在@ModelAttribute中进行参数获取，然后转换为相应的对象,获取后对参数进行验证，但是验证失败后我们要怎么处理了，这里面没办法返回错误码呀，所以如果验证失败就抛出异常，然后再@ExceptionHandler中进行统一处理。验证通过就吧获取的参数返回即可，那么此时在controller中获取参数需要使用@ModelAttribute进行获取。代码如下：

@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 {    
    //获取参数
        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不能为空");
            }else if(StringUtils.isBlank(token)){
                throw new ValidateException( Enums.ERROR_TOKEN_NOT_NULL,
                        "token不能为空");
            }else if(validate(token)){
                        throw new ValidateException( Enums.ERROR_TOKEN_INVALID,
                        "无效的token");  
              }
        }
        return paramBean;    
    }
    
     //捕获ValidateException的异常，统一返回
    @ExceptionHandler({ValidateException.class})
    @ResponseBody
    public ResultBean validateException(ValidateException ex){
        ResultBean result = new ResultBean();
        result.setResultCode(ex.getResultCode());
        result.setResultMsg(ex.getResultMsg());
        return result;
    }
}

四:隐患

几天后，测试发现了一个问题，就是比如我的返回数据，我想转换时间不反回长整形，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> 

测试得到的结果是

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

想把所有的时间都转换了，但是发现这个在我接收参数的时候都有异常。今天在某位大神的指导下发现了问题所在，我们在加了转换器后，在发送请求的时候会讲json数据使用MappingJackson2HttpMessageConverter此类进行转换，那么到了HttpEntity时已经是对象了但是我们却还是使用HttpEntity<String>接收
所以一直抱上面的错误，转换异常。所以我们可以尝试如下

ObjectMapper objectMapper = new ObjectMapper();
String json="{\n"+"\t\"appId":"\"123567\",\n"+"\t\"appcode":"\"sdasfa\"+"}";
objectMapper.readValue(json,String.class);

此时就会报错如上。所以接收点需要修改为HttpEntity<ParamEngine>的写法，接收处就不需要在转换类型，getBody()后就是ParamEngine对象。

五：浩学习

                                 __                                                        
                   __  _  ____ __|  |__ _____    ___
                   \ \/ \/ /  |  \  |  \\__  \  /  _ \   
                    \     /|  |  /   Y  \/ __ \(  <_> )
                     \/\_/ |____/|___|  (____  /\____/ 
                                      \/     \/          
走在自己的路上，遇到要遇到的人，经历要经历的事，这才是我们需要面对的。努力，come on!!!
                                                        公元2016年12月7号凌晨00点35分