解决在Filter中读取Request中的流后, 然后再Control中读取不到的做法

我们来看一下核心代码: filter中主要做的事情, 就是来校验请求是否合法, 是否有篡改过值.

@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {

if (Boolean.valueOf(authentication)) {
HttpServletRequest httpServletRequest = (HttpServletRequest) request;
if (BasicdataCommonsConstant.POST.equalsIgnoreCase(httpServletRequest.getMethod())) {
// 防止流读取一次后就没有了, 所以需要将流继续写出去
ServletRequest requestWrapper = new BodyReaderHttpServletRequestWrapper(httpServletRequest);
String body = HttpHelper.getBodyString(requestWrapper);
if (StringUtils.isBlank(body)) {
LOGGER.error("非法请求, 没有APP_KEY, APP_SECRET");
OutWriterUtil.outJson(response, gson.toJson(new Response(ErrorCode.AUTH_ERROR_ILLEGAL_FROMTYPE)));
return;
}
Map<String, String> parameters = gson.fromJson(body, new TypeToken<Map<String, String>>() {
}.getType());

String APP_KEY = parameters.get("appKey");
String APP_SECRET = parameters.get("appSecret");

TAuthUser authUser = authUserMap.get(APP_KEY);
if (authUser == null) {
LOGGER.error("非法请求, 没有APP_KEY, APP_SECRET");
OutWriterUtil.outJson(response, gson.toJson(new Response(ErrorCode.AUTH_ERROR_ILLEGAL_FROMTYPE)));
return;
} else if (StringUtils.isBlank(APP_SECRET)) {
LOGGER.error("非法请求, APP_SECRET为空, user={}", gson.toJson(authUser));
OutWriterUtil.outJson(response, gson.toJson(new Response(ErrorCode.AUTH_ERROR_FROMTYPE_AND_KEY_CANNT_BE_NULL)));
return;
} else if (!APP_SECRET.equals(authUser.getAppSecret())) {
LOGGER.error("非法请求: 没有APP_KEY, APP_SECRET不匹配. user={}, password={}, name={}", APP_KEY, APP_SECRET, authUser.getName());
OutWriterUtil.outJson(response, gson.toJson(new Response(ErrorCode.AUTH_ERROR_ILLEGAL_KEY)));
return;
}
String SIGNATURE = parameters.get("signature");
// 对参数进行签名
String md5 = SignatureUtil.decryptSignature(parameters);
if (!md5.equals(SIGNATURE)) {
LOGGER.error("非法请求, signature ={}", SIGNATURE);
OutWriterUtil.outJson(response, gson.toJson(new Response(ErrorCode.AUTH_ERROR_SIGNATURE_ERROR)));
return;
}
threadLocalUser.setAuthUser(authUser);
chain.doFilter(requestWrapper, response);
}
}
chain.doFilter(request, response);
}

大家都知道, 流只能读一次, 读了就没有了, 为了后面的代码还能够取得流, 我们应该还需要将其写出去才行.
所以, 我新建立了一个类. 看代码:

import javax.servlet.ReadListener;
import javax.servlet.ServletInputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.nio.charset.Charset;

/**
* Created with antnest-platform
* User: chenyuan
* Date: 12/31/14
* Time: 8:49 PM
*/
public class BodyReaderHttpServletRequestWrapper extends HttpServletRequestWrapper {

private final byte[] body;

public BodyReaderHttpServletRequestWrapper(HttpServletRequest request) throws IOException {
super(request);
body = HttpHelper.getBodyString(request).getBytes(Charset.forName("UTF-8"));
}

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

@Override
public ServletInputStream getInputStream() throws IOException {

final ByteArrayInputStream bais = new ByteArrayInputStream(body);

return new ServletInputStream() {

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

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

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

@Override
public void setReadListener(ReadListener readListener) {

}
};
}
}

import javax.servlet.ServletRequest;
import javax.servlet.http.HttpServletRequest;
import java.io.BufferedInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;

/**
* Created with antnest-platform
* User: chenyuan
* Date: 12/24/14
* Time: 10:39 AM
*/
public class HttpHelper {

/**
* 获取请求Body
*
* @param request
* @return
*/
public static String getBodyString(ServletRequest request) {
StringBuilder sb = new StringBuilder();
InputStream inputStream = null;
BufferedReader reader = null;
try {
inputStream = request.getInputStream();
reader = new BufferedReader(new InputStreamReader(inputStream, Charset.forName("UTF-8")));
String line = "";
while ((line = reader.readLine()) != null) {
sb.append(line);
}
} catch (IOException e) {
e.printStackTrace();
} finally {
if (inputStream != null) {
try {
inputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
if (reader != null) {
try {
reader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
return sb.toString();
}

}

请注意这里的编码, 最好将其转换成UTF-8的编码格式, 不然你获取到的中文则会使乱码的. 我自己也习惯于UTF-8的编码.
这样子就应该差不多了哦~