Java 如何在筛选器中获取请求

我想在RESTWeb服务项目中记录请求主体的所有请求和消息。 我使用Spring和json消息转换器。 但是我面临java.lang.IllegalStateException：这个请求已经调用了getReader（）。 我怎样才能解决这个问题？或 还有别的办法吗

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5"
    xmlns="http://java.sun.com/xml/ns/javaee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
    <welcome-file-list>
        <welcome-file>index.jsp</welcome-file>
    </welcome-file-list>
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>/WEB-INF/spring/root-context.xml</param-value>
    </context-param>
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>
    <servlet>
        <servlet-name>appServlet</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>/WEB-INF/spring/appServlet/servlet-context.xml</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>appServlet</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>
    <filter>
        <filter-name>LogFilter</filter-name>
        <filter-class>com.cmpolaris.system.LogFilter</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>LogFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>
</web-app>

我面临这个例外

INFO : com.cmpolaris.system.LogFilter - IP 192.168.1.95, Time Wed Sep 03 13:23:31 MMT 2014
    INFO : com.cmpolaris.system.LogFilter - Request Message
    INFO : com.cmpolaris.system.LogFilter - {"userId":"KTT","pwd":"ktdt","devID":"","userGroup":"SaleMan"}
    Sep 3, 2014 1:23:31 PM org.apache.catalina.core.StandardWrapperValve invoke
    SEVERE: Servlet.service() for servlet [appServlet] in context with path [/cmpolaris] threw exception [Request processing failed; nested exception is java.lang.IllegalStateExcepti
    on: getReader() has already been called for this request] with root cause
    java.lang.IllegalStateException: getReader() has already been called for this request
        at org.apache.catalina.connector.Request.getInputStream(Request.java:1052)
        at org.apache.catalina.connector.RequestFacade.getInputStream(RequestFacade.java:368)
        at org.springframework.http.server.ServletServerHttpRequest.getBody(ServletServerHttpRequest.java:131)
        at org.springframework.http.converter.json.MappingJackson2HttpMessageConverter.readJavaType(MappingJackson2HttpMessageConverter.java:178)
        at org.springframework.http.converter.json.MappingJackson2HttpMessageConverter.read(MappingJackson2HttpMessageConverter.java:173)
        at org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodArgumentResolver.readWithMessageConverters(AbstractMessageConverterMethodArgumentResolver.
    java:143)
        at org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.readWithMessageConverters(RequestResponseBodyMethodProcessor.java:180)
        at org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.resolveArgument(RequestResponseBodyMethodProcessor.java:95)
        at org.springframework.web.method.support.HandlerMethodArgumentResolverComposite.resolveArgument(HandlerMethodArgumentResolverComposite.java:77)
        at org.springframework.web.method.support.InvocableHandlerMethod.getMethodArgumentValues(InvocableHandlerMethod.java:162)
        at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:123)
        at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104)
        at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:745)
        at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:686)
        at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:80)
        at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:925)
        at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:856)
        at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:936)
        at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:838)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:641)
        at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:812)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:304)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
        at com.cmpolaris.system.LogFilter.doFilter(LogFilter.java:32)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:240)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:164)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:164)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
        at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:562)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:394)
        at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:243)
        at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:188)
        at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:166)
        at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:302)
        at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
        at java.lang.Thread.run(Unknown Source)

---

你知道请求转储程序过滤器吗？

---

根据使用tomcat的堆栈跟踪，请参阅了解用法。

将请求对象包装到另一个类，然后再转发到链过滤器。 这样，就可以避免使用流问题

例如，您可以使用此类：

在您的第一个过滤器中，首先将其包装：

public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain) throws IOException, ServletException {
        // use wrapper to read multiple times the content
        AuthenticationRequestWrapper request = new AuthenticationRequestWrapper((HttpServletRequest) req);
        HttpServletResponse response = (HttpServletResponse) resp;
        chain.doFilter(request,response);
}

---

使用的子类之一，并将

includePayload

属性设置为

true

（默认值为

false

）

假设您希望使用使用Commons日志记录来记录消息，请将添加到web.xml并为

includePayload

属性包含init参数

<filter>
    <filter-name>LogFilter</filter-name>
    <filter-class>org.springframework.web.filter.CommonsRequestLoggingFilter</filter-class>
    <init-param>
        <param-name>includePayload</param-name>
        <param-value>true</param-value>
    </init-param>    
</filter>
<filter-mapping>
    <filter-name>LogFilter</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>

对数滤波器
org.springframework.web.filter.commonRequestLoggingFilter
包括付款
真的
对数滤波器
/*

要包含有关客户端（用户、会话ID、客户端）的更多信息，请将

includeClientInfo

属性设置为

true

只有在调试日志记录打开时才会记录消息，因此请确保

commonRequestLoggingFilter

的日志级别至少为

debug

---

过滤器将把请求包装在一个包装器中，这样您就可以多次读取请求。

看看请求包装器&BTW with getRemoteAddr-您不能相信它是客户端的IPR，您想用过滤器做什么？您正在过滤器中调用getReader（），而您的servlet尝试在之后的某个地方调用getInputStream（）（通常在呈现某些内容时）。因此出现了例外。是的，我只是在测试。。。我想得到请求体，即使这个请求是400个错误的请求。我发现如何获取请求正文的消息。他们说的是getReader（）和getInputStream（）。但是我不行。请求包装器在这里可以正常工作。不确定是否有更好的方法可用于springSpring，Spring已经提供了这样做的过滤器。请看一下的子类。不需要自己写。

public class AuthenticationRequestWrapper extends HttpServletRequestWrapper {

    private final String payload;

    public AuthenticationRequestWrapper (HttpServletRequest request) throws AuthenticationException {
        super(request);

        // read the original payload into the payload variable
        StringBuilder stringBuilder = new StringBuilder();
        BufferedReader bufferedReader = null;
        try {
            // read the payload into the StringBuilder
            InputStream inputStream = request.getInputStream();
            if (inputStream != null) {
                bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
                char[] charBuffer = new char[128];
                int bytesRead = -1;
                while ((bytesRead = bufferedReader.read(charBuffer)) > 0) {
                    stringBuilder.append(charBuffer, 0, bytesRead);
                }
            } else {
                // make an empty string since there is no payload
                stringBuilder.append("");
            }
        } catch (IOException ex) {
            log.error("Error reading the request payload", ex);
            throw new AuthenticationException("Error reading the request payload", ex);
        } finally {
            if (bufferedReader != null) {
                try {
                    bufferedReader.close();
                } catch (IOException iox) {
                    // ignore
                }
            }
        }
        payload = stringBuilder.toString();
    }

    @Override
    public ServletInputStream getInputStream () throws IOException {
        final ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(payload.getBytes());
        ServletInputStream inputStream = new ServletInputStream() {
            public int read () 
                throws IOException {
                return byteArrayInputStream.read();
            }
        };
        return inputStream;
    }
}

public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain) throws IOException, ServletException {
        // use wrapper to read multiple times the content
        AuthenticationRequestWrapper request = new AuthenticationRequestWrapper((HttpServletRequest) req);
        HttpServletResponse response = (HttpServletResponse) resp;
        chain.doFilter(request,response);
}

<filter>
    <filter-name>LogFilter</filter-name>
    <filter-class>org.springframework.web.filter.CommonsRequestLoggingFilter</filter-class>
    <init-param>
        <param-name>includePayload</param-name>
        <param-value>true</param-value>
    </init-param>    
</filter>
<filter-mapping>
    <filter-name>LogFilter</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>