截取request并处理
SpringMVC在处理@RequestBody类型的参数的时候，是不是使用的我重写的这些方法呢？（getQueryString()、getParameter(String name)、getParameterValues(String name)、getParameterMap()）。打了个日志，发现还真不是这些方法。
于是搜索了一下Springboot拦截器获取@RequestBody参数，碰到了这篇文章。首先的新发现是Spring MVC 在获取@RequestBody参数的时候使用的是getInputStream()方法。嗯？（斜眼笑）那我是不是可以重写这个方法获取到输入流的字符串，然后直接处理一下？
import org.apache.commons.text.StringEscapeUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
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.StandardCharsets;
import java.util.Map;
/**
* 重新包装一下Request。重写一些获取参数的方法，将每个参数都进行过滤
*/
public class XSSHttpServletRequestWrapper extends HttpServletRequestWrapper {
private static final Logger logger = LoggerFactory.getLogger(XSSHttpServletRequestWrapper.class);
private HttpServletRequest request;
/**
* 请求体 RequestBody
*/
private String reqBody;
/**
* Constructs a request object wrapping the given request.
*
* @param request The request to wrap
* @throws IllegalArgumentException if the request is null
*/
public XSSHttpServletRequestWrapper(HttpServletRequest request) {
super(request);
logger.info("---xss XSSHttpServletRequestWrapper created-----");
this.request = request;
reqBody = getBodyString();
}
@Override
public String getQueryString() {
return StringEscapeUtils.escapeHtml4(super.getQueryString());
}
/**
* The default behavior of this method is to return getParameter(String
* name) on the wrapped request object.
*
* @param name
*/
@Override
public String getParameter(String name) {
logger.info("---xss XSSHttpServletRequestWrapper work getParameter-----");
String parameter = request.getParameter(name);
if (StringUtil.isNotBlank(parameter)) {
logger.info("----filter before--name:{}--value:{}----", name, parameter);
parameter = StringEscapeUtils.escapeHtml4(parameter);
logger.info("----filter after--name:{}--value:{}----", name, parameter);
}
return parameter;
}
/**
* The default behavior of this method is to return
* getParameterValues(String name) on the wrapped request object.
*
* @param name
*/
@Override
public String[] getParameterValues(String name) {
logger.info("---xss XSSHttpServletRequestWrapper work getParameterValues-----");
String[] parameterValues = request.getParameterValues(name);
if (!CollectionUtil.isEmpty(parameterValues)) {
// 经 “@Belief_7” 指正 这种方式不能更改parameterValues里面的值，要换成下面的写法
//for (String value : parameterValues) {
// logger.info("----filter before--name:{}--value:{}----", name, value);
// value = StringEscapeUtils.escapeHtml4(value);
// logger.info("----filter after--name:{}--value:{}----", name, value);
// }
for (int i = 0; i < parameterValues.length; i++)
{
parameterValues[i] = StringEscapeUtils.escapeHtml4(parameterValues[i]);
}
}
return parameterValues;
}
/**
* The default behavior of this method is to return getParameterMap() on the
* wrapped request object.
*/
@Override
public Map<String, String[]> getParameterMap() {
logger.info("---xss XSSHttpServletRequestWrapper work getParameterMap-----");
Map<String, String[]> map = request.getParameterMap();
if (map != null && !map.isEmpty()) {
for (String[] value : map.values()) {
/*循环所有的value*/
for (String str : value) {
logger.info("----filter before--value:{}----", str, str);
str = StringEscapeUtils.escapeHtml4(str);
logger.info("----filter after--value:{}----", str, str);
}
}
}
return map;
}
/*重写输入流的方法，因为使用RequestBody的情况下是不会走上面的方法的*/
/**
* The default behavior of this method is to return getReader() on the
* wrapped request object.
*/
@Override
public BufferedReader getReader() throws IOException {
logger.info("---xss XSSHttpServletRequestWrapper work getReader-----");
return new BufferedReader(new InputStreamReader(getInputStream()));
}
/**
* The default behavior of this method is to return getInputStream() on the
* wrapped request object.
*/
@Override
public ServletInputStream getInputStream() throws IOException {
logger.info("---xss XSSHttpServletRequestWrapper work getInputStream-----");
/*创建字节数组输入流*/
final ByteArrayInputStream bais = new ByteArrayInputStream(reqBody.getBytes(StandardCharsets.UTF_8));
return new ServletInputStream() {
@Override
public boolean isFinished() {
return false;
}
@Override
public boolean isReady() {
return false;
}
@Override
public void setReadListener(ReadListener listener) {
}
@Override
public int read() throws IOException {
return bais.read();
}
};
}
/**
* 获取请求体
*
* @return 请求体
*/
private String getBodyString() {
StringBuilder builder = new StringBuilder();
InputStream inputStream = null;
BufferedReader reader = null;
try {
inputStream = request.getInputStream();
reader = new BufferedReader(new InputStreamReader(inputStream));
String line;
while ((line = reader.readLine()) != null) {
builder.append(line);
}
} catch (IOException e) {
logger.error("-----get Body String Error:{}----", e.getMessage(), e);
} finally {
if (inputStream != null) {
try {
inputStream.close();
} catch (IOException e) {
logger.error("-----get Body String Error:{}----", e.getMessage(), e);
}
}
if (reader != null) {
try {
reader.close();
} catch (IOException e) {
logger.error("-----get Body String Error:{}----", e.getMessage(), e);
}
}
}
return builder.toString();
}
}
private String reqBody;
可以定义一个private byte[] reqBody = null; 取代上述变量
定义getReqBody方法，如果reqBody为空的话，从super.getInputStream()中获取（int read = inputStream.read(byteBuffer, readBytesOff, contentLength - readBytesOff);）。
同理获取super.getContentLength()。
篡改时改reqBody。
重写getInputStream，优先从reqBody中取数据（通过bias）。