解決spring 處理request.getInputStream()輸入流只能讀取一次問題

更新時間：2020年09月24日 15:09:05 作者：韋邦杠

這篇文章主要介紹了解決spring 處理request.getInputStream()輸入流只能讀取一次問題，具有很好的參考價值，希望對大家有所幫助。一起跟隨小編過來看看吧

一般我們會在InterceptorAdapter攔截器中對請求進(jìn)行驗(yàn)證

正常普通接口請求，request.getParameter()可以獲取，能多次讀取

如果我們的接口是用@RequestBody來接受數(shù)據(jù)，那么我們在攔截器中

需要讀取request的輸入流，因?yàn)?ServletRequest中g(shù)etReader()和getInputStream()只能調(diào)用一次

這樣就會導(dǎo)致controller 無法拿到數(shù)據(jù)。

解決方法：

1、自定義一個類 BodyReaderHttpServletRequestWrapper.java

import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStreamReader;

import javax.servlet.ReadListener;
import javax.servlet.ServletInputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import org.springframework.util.StreamUtils;

/**
 * @author WBG
 * @date 2020/6/22 10:42
 * @describe
 */
public class BodyReaderHttpServletRequestWrapper extends HttpServletRequestWrapper{

 private byte[] requestBody = null;//用于將流保存下來

 public BodyReaderHttpServletRequestWrapper(HttpServletRequest request) throws IOException {
 super(request);
 requestBody = StreamUtils.copyToByteArray(request.getInputStream());

 }

 @Override
 public ServletInputStream getInputStream() throws IOException {

 final ByteArrayInputStream bais = new ByteArrayInputStream(requestBody);

 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) {

  }
 };
 }

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

2、自定義 MyFilter 繼承Filter

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

/**
 * @author WBG
 * @date 2020/6/22 14:32
 * @describe
 */
public class MyFilter implements Filter {
 @Override
 public void init(FilterConfig filterConfig) throws ServletException {
 System.out.println("開始");
 }

 @Override
 public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
 ServletRequest requestWrapper=null;
 if(request instanceof HttpServletRequest) {
  requestWrapper=new BodyReaderHttpServletRequestWrapper((HttpServletRequest)request);
 }
 if(requestWrapper==null) {
  chain.doFilter(request, response);
 }else {
  System.out.println("------------------------------請求報文----------------------------------");
  System.out.println(getParamsFromRequestBody((HttpServletRequest) requestWrapper));
  System.out.println("------------------------------請求報文----------------------------------");
  chain.doFilter(requestWrapper, response);
 }

 }
 /* *
 * 獲取請求體內(nèi)容
 * @return
 * @throws IOException
 */

 private String getParamsFromRequestBody(HttpServletRequest request) throws IOException {
 BufferedReader br = null;
 String listString = "";
 try {
  br = request.getReader();

  String str = "";

  while ((str = br.readLine()) != null) {
  listString += str;
  }
 } catch (IOException e) {
  e.printStackTrace();
 }
 return listString;
 }

 @Override
 public void destroy() {
 System.out.println("destroy");
 }
}

3、web.xm配置過濾器

<!--定義過濾器-->
 <filter>
 <!--定義過濾器攔截URL地址-->
 <filter-name>test2</filter-name>
 <!--過濾器的文件-->
 <filter-class>com.zhhy.hy2000interface.utils.filter.MyFilter</filter-class>
 </filter>
 <filter-mapping>
 <!--過濾器的名稱-->
 <filter-name>test2</filter-name>
 <!--過濾器負(fù)責(zé)攔截的URL-->
 <!-- /* 會把所有的請求攔截下來 -->
 <url-pattern>/*</url-pattern>

 </filter-mapping>

（如果是Springboot，使用注解即可）