如何多次读取request.getInputStream()

时间:2010-12-15 10:51:47

标签: java servlets java-ee servlet-filters

我有这段代码:

@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
        throws IOException, ServletException {
    logger.info("Filter start...");

    HttpServletRequest httpRequest = (HttpServletRequest) request;
    HttpServletResponse httpResponse = (HttpServletResponse) response;

    String ba = getBaId(getBody(httpRequest));

    if (ba == null) {
        logger.error("Wrong XML");
        httpResponse.setStatus(HttpServletResponse.SC_BAD_REQUEST);
    } else {      

        if (!clients.containsKey(ba)) {
            clients.put(ba, 1);
            logger.info("Client map : init...");
        } else {
            clients.put(ba, clients.get(ba).intValue() + 1);
            logger.info("Threads for " + ba + " = " + clients.get(ba).toString());
        }

        chain.doFilter(request, response);
    }
}

和这个web.xml(包被缩短,名称改变了,但看起来一样)

<?xml version="1.0" encoding="ISO-8859-1"?>
<web-app>
  <filter>
    <filter-name>TestFilter</filter-name>
    <filter-class>pkg.TestFilter</filter-class>
  </filter>
  <filter-mapping>
    <filter-name>TestFilter</filter-name>
    <url-pattern>/*</url-pattern>
  </filter-mapping>

  <context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>WEB-INF/applicationContext.xml</param-value>
  </context-param>

  <listener>
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
  </listener>

  <servlet>
    <servlet-name>Name</servlet-name>
    <display-name>Name</display-name>
    <servlet-class>pkg.Name</servlet-class>
    <load-on-startup>1</load-on-startup>
  </servlet>
  <servlet-mapping>
    <servlet-name>Name</servlet-name>
    <url-pattern>/services/*</url-pattern>
  </servlet-mapping>
</web-app>

我想在Filter之后调用Servlet。我希望chain.doFilter(...)可以做到这一点,但我总是在chain.doFilter(...)的行上出现这个错误:

java.lang.IllegalStateException: getInputStream() can't be called after getReader()
at com.caucho.server.connection.AbstractHttpRequest.getInputStream(AbstractHttpRequest.java:1933)
at org.apache.cxf.transport.http.AbstractHTTPDestination.setupMessage(AbstractHTTPDestination.java:249)
at org.apache.cxf.transport.servlet.ServletDestination.invoke(ServletDestination.java:82)
at org.apache.cxf.transport.servlet.ServletController.invokeDestination(ServletController.java:283)
at org.apache.cxf.transport.servlet.ServletController.invoke(ServletController.java:166)
at org.apache.cxf.transport.servlet.AbstractCXFServlet.invoke(AbstractCXFServlet.java:174)
at org.apache.cxf.transport.servlet.AbstractCXFServlet.doPost(AbstractCXFServlet.java:152)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:153)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:91)
at com.caucho.server.dispatch.ServletFilterChain.doFilter(ServletFilterChain.java:103)
at pkg.TestFilter.doFilter(TestFilter.java:102)
at com.caucho.server.dispatch.FilterFilterChain.doFilter(FilterFilterChain.java:87)
at com.caucho.server.webapp.WebAppFilterChain.doFilter(WebAppFilterChain.java:187)
at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:265)
at com.caucho.server.http.HttpRequest.handleRequest(HttpRequest.java:273)
at com.caucho.server.port.TcpConnection.run(TcpConnection.java:682)
at com.caucho.util.ThreadPool$Item.runTasks(ThreadPool.java:743)
at com.caucho.util.ThreadPool$Item.run(ThreadPool.java:662)
at java.lang.Thread.run(Thread.java:619)

6 个答案:

答案 0 :(得分:10)

根据接受的答案运作代码。

public class CustomHttpServletRequestWrapper extends HttpServletRequestWrapper {

private static final Logger logger = Logger.getLogger(CustomHttpServletRequestWrapper.class);
private final String body;

public CustomHttpServletRequestWrapper(HttpServletRequest request) {
    super(request);

    StringBuilder stringBuilder = new StringBuilder();  
    BufferedReader bufferedReader = null;  

    try {  
        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 {  
            stringBuilder.append("");  
        }  
    } catch (IOException ex) {  
        logger.error("Error reading the request body...");  
    } finally {  
        if (bufferedReader != null) {  
            try {  
                bufferedReader.close();  
            } catch (IOException ex) {  
                logger.error("Error closing bufferedReader...");  
            }  
        }  
    }  

    body = stringBuilder.toString();  
}

@Override  
public ServletInputStream getInputStream () throws IOException {          
    final ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(body.getBytes());

    ServletInputStream inputStream = new ServletInputStream() {  
        public int read () throws IOException {  
            return byteArrayInputStream.read();  
        }  
    };

    return inputStream;  
} 
}

答案 1 :(得分:6)

你可能会在{/ p>中使用getReader()开始使用HttpServletRequest

String ba = getBaId(getBody(httpRequest)); 

您的servlet尝试在同一请求上调用getInputStream(),这是不允许的。您需要做的是使用ServletRequestWrapper制作请求正文的副本,以便您可以使用多种方法阅读它。我没有时间找到一个完整的例子知道...对不起......

答案 2 :(得分:6)

这对我有用。它实现了getInputStream

private class MyHttpServletRequestWrapper extends HttpServletRequestWrapper {

    private byte[] body;

    public MyHttpServletRequestWrapper(HttpServletRequest request) {
        super(request);
        try {
            body = IOUtils.toByteArray(request.getInputStream());
        } catch (IOException ex) {
            body = new byte[0];
        }
    }

    @Override
    public ServletInputStream getInputStream() throws IOException {
        return new ServletInputStream() {
            ByteArrayInputStream bais = new ByteArrayInputStream(body);

            @Override
            public int read() throws IOException {
                return bais.read();
            }
        };
    }

}

然后你在你的方法中使用:

//copy body
servletRequest = new MyHttpServletRequestWrapper(servletRequest);

答案 3 :(得分:4)

对于Servlet 3.1

import _ from "lodash"
import { getShifts} from '../actions';

export default function(state = {}, action) {
switch(action.type){
 case SHIFTS_LOAD_SUCCESS:
    return { ...state, rota: action.response };
  }
 }

答案 4 :(得分:1)

servlet请求中的inputStream只能使用一次因为它是流,你可以存储它然后从字节数组中获取它,这可以解决。

public class HttpServletRequestWrapper extends javax.servlet.http.HttpServletRequestWrapper {

private final byte[] body;

public HttpServletRequestWrapper(HttpServletRequest request)
        throws IOException {
    super(request);
    body = StreamUtil.readBytes(request.getReader(), "UTF-8");
}

@Override
public BufferedReader getReader() throws IOException {
    return new BufferedReader(new InputStreamReader(getInputStream()));
}

@Override
public ServletInputStream getInputStream() throws IOException {
    final ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(body);
    return new ServletInputStream() {

        @Override
        public int read() throws IOException {
            return byteArrayInputStream.read();
        }

        @Override
        public boolean isFinished() {
            return false;
        }

        @Override
        public boolean isReady() {
            return false;
        }

        @Override
        public void setReadListener(ReadListener arg0) {
        }
    };
}
}
过滤器中的

ServletRequest requestWrapper = new HttpServletRequestWrapper(request);

答案 5 :(得分:1)

request.getInputStream()只允许读取一次。为了多次使用此方法,我们需要为HttpServletReqeustWrapper类添加额外的自定义任务。请参阅下面的示例包装类。

public class MultiReadHttpServletRequest extends HttpServletRequestWrapper {
    private ByteArrayOutputStream cachedBytes;

    public MultiReadHttpServletRequest(HttpServletRequest request) {
        super(request);
    }

    @Override
    public ServletInputStream getInputStream() throws IOException {
        if (cachedBytes == null)
            cacheInputStream();

        return new CachedServletInputStream();
    }

    @Override
    public BufferedReader getReader() throws IOException {
        return new BufferedReader(new InputStreamReader(getInputStream()));
    }

    private void cacheInputStream() throws IOException {
        /*
         * Cache the inputstream in order to read it multiple times. For convenience, I use apache.commons IOUtils
         */
        cachedBytes = new ByteArrayOutputStream();
        IOUtils.copy(super.getInputStream(), cachedBytes);
    }

    /* An inputstream which reads the cached request body */
    public class CachedServletInputStream extends ServletInputStream {
        private ByteArrayInputStream input;

        public CachedServletInputStream() {
            /* create a new input stream from the cached request body */
            input = new ByteArrayInputStream(cachedBytes.toByteArray());
        }

        @Override
        public int read() throws IOException {
            return input.read();
        }
    }
}

就我而言,我将所有传入的请求都跟踪到日志中。我创建了一个过滤器

public class TracerRequestFilter实现Filter {     private static final Logger LOG = LoggerFactory.getLogger(TracerRequestFilter.class);

@Override
public void destroy() {

}

@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException,
        ServletException {
    final HttpServletRequest req = (HttpServletRequest) request;

    try {
        if (LOG.isDebugEnabled()) {
            final MultiReadHttpServletRequest wrappedRequest = new MultiReadHttpServletRequest(req);
            // debug payload info
            logPayLoad(wrappedRequest);
            chain.doFilter(wrappedRequest, response);
        } else {
            chain.doFilter(request, response);
        }
    } finally {
        LOG.info("end-of-process");
    }
}

private String getRemoteAddress(HttpServletRequest req) {
    String ipAddress = req.getHeader("X-FORWARDED-FOR");
    if (ipAddress == null) {
        ipAddress = req.getRemoteAddr();
    }
    return ipAddress;
}

private void logPayLoad(HttpServletRequest request) {
    final StringBuilder params = new StringBuilder();
    final String method = request.getMethod().toUpperCase();
    final String ipAddress = getRemoteAddress(request);
    final String userAgent = request.getHeader("User-Agent");
    LOG.debug(String.format("============debug request=========="));
    LOG.debug(String.format("Access from ip:%s;ua:%s", ipAddress, userAgent));
    LOG.debug(String.format("Method : %s requestUri %s", method, request.getRequestURI()));
    params.append("Query Params:").append(System.lineSeparator());
    Enumeration<String> parameterNames = request.getParameterNames();

    for (; parameterNames.hasMoreElements();) {
        String paramName = parameterNames.nextElement();
        String paramValue = request.getParameter(paramName);
        if ("password".equalsIgnoreCase(paramName) || "pwd".equalsIgnoreCase(paramName)) {
            paramValue = "*****";
        }
        params.append("---->").append(paramName).append(": ").append(paramValue).append(System.lineSeparator());
    }
    LOG.debug(params.toString());
    /** request body */

    if ("POST".equals(method) || "PUT".equals(method)) {
        try {
            LOG.debug(IOUtils.toString(request.getInputStream()));
        } catch (IOException e) {
            LOG.error(e.getMessage(), e);
        }
    }
    LOG.debug(String.format("============End-debug-request=========="));
}

@Override
public void init(FilterConfig arg0) throws ServletException {

}
}

它适用于Servlet 2.5和3.0。我看到所有请求参数都是表单编码和请求json正文。