1、问题描述
由于后端接口获取前端传过的参数是通过HttpServletRequest接收获取的。现有一需求需要在接口调用之前拦截接口进行业务处理。在拦截类中调用getInputStream()获取参数之后，在接口方法里获取参数为空。
2、解决方法
自定义一个过滤器过滤所有请求，使用HttpServletRequestWrapper将发送请求的流有容器储存起来，就可以多次调用了。
首先定义一个包装类RequestWrapper继承HttpServletRequestWrapper
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.CollectionUtils;
import org.springframework.util.StreamUtils;
import javax.servlet.ReadListener;
import javax.servlet.ServletInputStream;
import javax.servlet.ServletRequest;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import java.io.*;
import java.nio.charset.Charset;
import java.util.Map;
@Slf4j
public class RequestWrapper extends HttpServletRequestWrapper {
/**
* 存储body数据的容器
*/
private final byte[] body;
//private Map<String, String[]> parameterMap;
// @Override
// public String[] getParameterValues(String name) {
// if(!CollectionUtils.isEmpty(parameterMap)) {
// return parameterMap.get(name);
// }
// return null;
// }
public RequestWrapper(HttpServletRequest request) throws IOException {
super(request);
//parameterMap = request.getParameterMap();
// 将body数据存储起来
body = StreamUtils.copyToByteArray(request.getInputStream());
}
@Override
public BufferedReader getReader() throws IOException {
return new BufferedReader(new InputStreamReader(getInputStream()));
}
@Override
public ServletInputStream getInputStream() throws IOException {
final ByteArrayInputStream inputStream = new ByteArrayInputStream(body);
return new ServletInputStream() {
@Override
public int read() throws IOException {
return inputStream.read();
}
@Override
public boolean isFinished() {
return false;
}
@Override
public boolean isReady() {
return false;
}
@Override
public void setReadListener(ReadListener readListener) {
}
};
}
}
编写过滤器：
import lombok.extern.slf4j.Slf4j;
import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import java.io.IOException;
@Slf4j
@WebFilter(filterName = "streamFilter",urlPatterns = "/*")
public class RequestStreamFilter implements Filter {
@Override
public void init(javax.servlet.FilterConfig filterConfig) throws ServletException {
log.info("StreamFilter init...");
}
@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
ServletRequest requestWrapper = new RequestWrapper((HttpServletRequest) request);
chain.doFilter(requestWrapper, response);
}
@Override
public void destroy() {
log.info("StreamFilter destroy...");
}
}
版权声明：本文内容由互联网用户自发贡献，该文观点仅代表作者本人。本站仅提供信息存储空间服务，不拥有所有权，不承担相关法律责任。如发现本站有涉嫌侵权/违法违规的内容， 请发送邮件至 举报，一经查实，本站将立刻删除。
文章由极客之音整理，本文链接：https://www.bmabk.com/index.php/post/260222.html
