[英]POST parameter null, but present in body
我有一个在本地运行良好的应用程序,但在客户端它崩溃了,因为 POST 参数是 null。
((HttpServletRequest)request).getParameter("dtid");
这返回 null。
所以我添加了一个过滤器来记录请求的 GET/POST/BODY。 在本地,日志如下所示:
[方法:POST] [请求 URI:/peps/zkau] [请求参数:{dtid =z_0n8, uuid_0=x38Pz, data_0={"pageX":372,"pageY":103,"which":1,"x ":40.79998779296875,"y":4}, cmd_0=onClick}] [请求正文:] [远程地址:0:0:0:0:0:0:0:1]
我在请求参数中有 dtid 并且正文是空的。 在客户端,相同的日志如下所示:
[方法:POST] [请求 URI:/peps/zkau] [请求参数:{} ] [请求体:dtid=z_cb50&cmd_0=onOpen&uuid_0=l2sT30&data_0=%7B%22open%22%3Atrue%2C%22reference%22%3A%22l2sT20 %22%7D&cmd_1=onClick&uuid_1=l2sT40&data_1=%7B%22pageX%22%3A323%2C%22pageY%22%3A138%2C%22which%22%3A1%2C%22x%22%3A323%2C%22y%22%3A138% 7D&cmd_2=onOpen&uuid_2=l2sT30&data_2=%7B%22open%22%3Afalse%7D] [远程地址:xxxx]
参数是一个空的map,但是body是满的。 身体似乎没有经过处理,这可能是什么原因? 为什么body没有解析并注入参数map?
谢谢
这是我的过滤器:
public class PepsParamFilter implements Filter {
private static final Logger LOG = Logger.getLogger(PepsParamFilter.class.getName());
@Override
public void init(FilterConfig filterConfig) throws ServletException {
}
@Override
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException {
try {
HttpServletRequest httpServletRequest = (HttpServletRequest) request;
Map<String, String> requestMap = this.getTypesafeRequestMap(httpServletRequest);
BufferedRequestWrapper bufferedReqest = new BufferedRequestWrapper(httpServletRequest);
chain.doFilter(bufferedReqest, response);
//Request
final StringBuilder reqMessage = new StringBuilder("").append("[METHOD:")
.append(httpServletRequest.getMethod())
.append("] [REQUEST URI:")
.append(httpServletRequest.getRequestURI())
.append("] [REQUEST PARAMETERS:").append(requestMap)
.append("] [REQUEST BODY:")
.append(bufferedReqest.getRequestBody())
.append("] [REMOTE ADDRESS:")
.append(httpServletRequest.getRemoteAddr()).append("]");
if(!httpServletRequest.getRequestURI().endsWith(".gif")
&& !httpServletRequest.getRequestURI().endsWith(".png")
&& !httpServletRequest.getRequestURI().endsWith(".css")
) {
LOG.info(reqMessage);
}
} catch (Throwable a) {
LOG.error(a.getMessage(),a);
}
}
private Map<String, String> getTypesafeRequestMap(HttpServletRequest request) {
Map<String, String> typesafeRequestMap = new HashMap<String, String>();
Enumeration<?> requestParamNames = request.getParameterNames();
while (requestParamNames.hasMoreElements()) {
String requestParamName = (String) requestParamNames.nextElement();
String requestParamValue = request.getParameter(requestParamName);
typesafeRequestMap.put(requestParamName, requestParamValue);
}
return typesafeRequestMap;
}
@Override
public void destroy() {
}
private static final class BufferedRequestWrapper extends
HttpServletRequestWrapper {
private ByteArrayInputStream bais = null;
private ByteArrayOutputStream baos = null;
private BufferedServletInputStream bsis = null;
private byte[] buffer = null;
public BufferedRequestWrapper(HttpServletRequest req)
throws IOException {
super(req);
// Read InputStream and store its content in a buffer.
InputStream is = req.getInputStream();
this.baos = new ByteArrayOutputStream();
byte buf[] = new byte[1024];
int letti;
while ((letti = is.read(buf)) > 0) {
this.baos.write(buf, 0, letti);
}
this.buffer = this.baos.toByteArray();
}
@Override
public ServletInputStream getInputStream() {
this.bais = new ByteArrayInputStream(this.buffer);
this.bsis = new BufferedServletInputStream(this.bais);
return this.bsis;
}
@Override
public BufferedReader getReader() throws IOException {
return new BufferedReader(new InputStreamReader(this.getInputStream()));
}
String getRequestBody() throws IOException {
BufferedReader reader = new BufferedReader(new InputStreamReader(
this.getInputStream()));
String line = null;
StringBuilder inputBuffer = new StringBuilder();
do {
line = reader.readLine();
if (null != line) {
inputBuffer.append(line.trim());
}
} while (line != null);
reader.close();
return inputBuffer.toString().trim();
}
}
private static final class BufferedServletInputStream extends
ServletInputStream {
private ByteArrayInputStream bais;
public BufferedServletInputStream(ByteArrayInputStream bais) {
this.bais = bais;
}
@Override
public int available() {
return this.bais.available();
}
@Override
public int read() {
return this.bais.read();
}
@Override
public int read(byte[] buf, int off, int len) {
return this.bais.read(buf, off, len);
}
}
public class TeeServletOutputStream extends ServletOutputStream {
private final TeeOutputStream targetStream;
public TeeServletOutputStream(OutputStream one, OutputStream two) {
targetStream = new TeeOutputStream(one, two);
}
@Override
public void write(int arg0) throws IOException {
this.targetStream.write(arg0);
}
public void flush() throws IOException {
super.flush();
this.targetStream.flush();
}
public void close() throws IOException {
super.close();
this.targetStream.close();
}
}
}
3.1.1 参数可用时
以下是在将表单数据填充到参数集之前必须满足的条件:
- 请求是 HTTP 或 HTTPS 请求。
- HTTP 方法是 POST。
- 内容类型为 application/x-www-form-urlencoded。
- servlet 已对请求 object 的任何 getParameter 系列方法进行了初始调用。
如果不满足条件且 post 表单数据未包含在参数集中,则 post 数据必须仍可通过请求对象的输入 stream 提供给 servlet。 如果满足条件,则无法再从请求对象的输入 stream 直接读取发布表单数据。
您必须检查这些条件中的任何一个是否适用于您的本地或客户端系统。
可能还有其他过滤器(在您之前的过滤器链中),它们已经处理了请求正文,或者更改了内容类型,或者之前访问了 getParameter* 方法之一,或者包装了请求......(你明白了)
本质上,这两种状态都是有效的,具体取决于您之前的请求发生了什么。
首先要检查的是浏览器是否发送相同的请求(/正文)和标头。 例如在浏览器的开发者工具中。 如果它们相同,请检查您的 web.xml 以获取其他过滤器(例如,本地开发环境和生产环境之间的安全过滤器通常不同)。
通过 POST 调用,参数将在请求正文中发送,这发生在您服务器的日志中。 因此,您需要获取请求正文才能访问所需的参数,请参阅this question on how to get post data。
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