filter过滤器，解决request获取前端参数中，参数以json流的形式传输的问题

1、复制流的工具

import jodd.io.StreamUtil;

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;

/**
* Created by Administrator on 2018/1/12 0012.
*/
public class MAPIHttpServletRequestWrapper extends HttpServletRequestWrapper {
private final byte[] body;

/**
* Constructs a request object wrapping the given request.
*
* @param request
* @throws IllegalArgumentException if the request is null
*/
public MAPIHttpServletRequestWrapper(HttpServletRequest request) throws IOException {
super(request);
body = StreamUtil.readBytes(request.getInputStream());
}

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

@Override
public ServletInputStream getInputStream() {
final ByteArrayInputStream bais = new ByteArrayInputStream(body);
return new ServletInputStream() {
@Override
public boolean isFinished() {
return false;
}

/**
* Returns true if data can be read without blocking else returns
* false.
*
* @return <code>true</code> if data can be obtained without blocking,
* otherwise returns <code>false</code>.
* @since Servlet 3.1
*/
@Override
public boolean isReady() {
return false;
}

/**
* Instructs the <code>ServletInputStream</code> to invoke the provided
* {@link ReadListener} when it is possible to read
*
* @param readListener the {@link ReadListener} that should be notified
* when it's possible to read.
* @throws IllegalStateException if one of the following conditions is true
* <ul>
* <li>the associated request is neither upgraded nor the async started
* <li>setReadListener is called more than once within the scope of the same request.
* </ul>
* @throws NullPointerException if readListener is null
* @since Servlet 3.1
*/
@Override
public void setReadListener(ReadListener readListener) {

}

@Override
public int read() throws IOException {
return bais.read();
}
};
}
}
2、拦截器
import com.alibaba.fastjson.JSON;
import com.atc.beans.logger.LogParamVO;
import com.atc.beans.system.UserInfo;
import com.atc.framework.common.logger.LoggerService;
import com.atc.framework.common.utils.httprequest.MAPIHttpServletRequestWrapper;
import org.apache.commons.lang3.StringUtils;
import org.apache.shiro.SecurityUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;

import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import java.io.IOException;

/**
* Created by Administrator on 2018/1/12 0012.
*/
public class ParamFilter implements Filter {
private static final Logger LOGGER = LoggerFactory.getLogger(ParamFilter.class);

@Autowired
private LoggerService loggerService;

/**
* @param filterConfig
*/
@Override
public void init(FilterConfig filterConfig) throws ServletException {

}

/**
* @param request
* @param response
* @param chain
*/
@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
ServletRequest servletRequest = loggerService.writeLog(request);
chain.doFilter(servletRequest,response);
}

@Override
public void destroy() {

}

}


3、拦截器中需要执行的方法
import com.alibaba.fastjson.JSON;
import com.atc.beans.logger.LogParamVO;
import com.atc.beans.system.UserInfo;
import com.atc.framework.common.utils.httprequest.MAPIHttpServletRequestWrapper;
import org.apache.commons.lang3.StringUtils;
import org.apache.shiro.SecurityUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Service;

import javax.servlet.ServletInputStream;
import javax.servlet.ServletRequest;
import javax.servlet.http.HttpServletRequest;
import java.io.IOException;

/**
* Created by Administrator on 2018/1/12 0012.
*/
@Service
public class LoggerServiceImpl implements LoggerService {
private static final Logger LOGGER = LoggerFactory.getLogger(LoggerServiceImpl.class);
@Override
public ServletRequest writeLog(ServletRequest request) throws IOException {
ServletRequest requestWrapper = null;
if (request instanceof HttpServletRequest) {
requestWrapper = new MAPIHttpServletRequestWrapper((HttpServletRequest) request);
}

String requestURL = ((HttpServletRequest) requestWrapper).getRequestURL().toString();

//获取json
String contentType = requestWrapper.getContentType();
String paramJson = "";
if ("application/json; charset=UTF-8".equals(contentType)) {
paramJson = this.getJsonParam((HttpServletRequest) requestWrapper);
} else {
paramJson = JSON.toJSONString(requestWrapper.getParameterMap());
}
LogParamVO logParamVO = new LogParamVO(yhxm, ip, requestURL, browser, paramJson);

LOGGER.info("【Filter过滤用户操作日志】{}", JSON.toJSONString(logParamVO));

if (requestWrapper == null) {
return request;
} else {
return requestWrapper;
}
}

/**
* 获取Json数据
*
* @param request
* @return
*/
private String getJsonParam(HttpServletRequest request) {
String jsonParam = "";
ServletInputStream inputStream = null;
try {
int contentLength = request.getContentLength();
if (!(contentLength < 0)) {
byte[] buffer = new byte[contentLength];
inputStream = request.getInputStream();
for (int i = 0; i < contentLength; ) {
int len = inputStream.read(buffer, i, cont
afe4
entLength);
if (len == -1) {
break;
}
i += len;
}
jsonParam = new String(buffer, "utf-8");
}
} catch (IOException e) {
LOGGER.error("参数转换成json异常g{}", e);
} finally {
if (inputStream != null) {
try {
inputStream.close();
} catch (IOException e) {
LOGGER.error("参数转换成json异常s{}", e);
}
}
}
return jsonParam;
}

}