SpringBoot之HandlerInterceptor攔截器的使用 ——（三）獲取requestBody解決java.io.IOException: Stream closed
阿新 • • 發佈：2018-11-10
現在開發的專案是基於SpringBoot的maven專案，攔截器的使用很多時候是必不可少的，當有需要需要你對body中的值進行校驗，例如加密驗籤、防重複提交、內容校驗等等。
當你開開心心的在攔截器中通過request.getInputStream();獲取到body中的資訊後，你會發現你在controller中使用了@RequestBody註解獲取引數報如下錯誤
I/O error while reading input message; nested exception is java.io.IOException: Stream closed
org.springframework.http.converter.HttpMessageNotReadableException: IO流關閉只能讀取一次，接下來我們就開始解決這個BUG，有兩種大的方向：
這個需求咱不做了，特麼有本事就把東西都放在請求頭裡面傳過來；
解決流只能讀取一次的問題，讓它可以被多次重複讀取；
考慮到生活還要繼續，妻兒老小在家等著我回去告訴他們晚上吃冷麵還是雞，要這需求不給搞定那也只能去打包收拾東西滾蛋，回家路上順便賣點血換錢了，我選擇了第二種
最簡單的方案就是 先讀取流，然後在將流寫進去就行了
引入包
<dependency>
<groupId>org.apache.tomcat.embed</groupId>
<artifactId>tomcat-embed-core</artifactId>
<version>8.5.15</version>
</dependency>新建HttpHelper （用於讀取Body）
package com.xxx.util.core.filter.request;
import javax.servlet.http.HttpServletRequest;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.nio.charset.Charset;
public class HttpHelper {
public static String getBodyString(HttpServletRequest request) throws IOException {
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();
}
}新建RequestReaderHttpServletRequestWrapper（防止流丟失）
package com.xxx.util.core.filter.request;
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.nio.charset.Charset;
import javax.servlet.ReadListener;
import javax.servlet.ServletInputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
public class RequestReaderHttpServletRequestWrapper extends HttpServletRequestWrapper{
private final byte[] body;
public RequestReaderHttpServletRequestWrapper(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) {
}
};
}
}新建HttpServletRequestReplacedFilter(過濾器)
package com.xxx.util.core.filter.request;
import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import java.io.IOException;
public class HttpServletRequestReplacedFilter implements Filter {
@Override
public void destroy() {
}
@Override
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException {
ServletRequest requestWrapper = null;
if(request instanceof HttpServletRequest) {
requestWrapper = new RequestReaderHttpServletRequestWrapper((HttpServletRequest) request);
}
//獲取請求中的流如何，將取出來的字串，再次轉換成流，然後把它放入到新request物件中。
// 在chain.doFiler方法中傳遞新的request物件
if(requestWrapper == null) {
chain.doFilter(request, response);
} else {
chain.doFilter(requestWrapper, response);
}
}
@Override
public void init(FilterConfig arg0) throws ServletException {
}
}最後我們只需要在Application.java中加上如下程式碼注入過濾器即可
@Bean
public FilterRegistrationBean httpServletRequestReplacedRegistration() {
FilterRegistrationBean registration = new FilterRegistrationBean();
registration.setFilter(new HttpServletRequestReplacedFilter());
registration.addUrlPatterns("/*");
registration.addInitParameter("paramName", "paramValue");
registration.setName("httpServletRequestReplacedFilter");
registration.setOrder(1);
return registration;
}如下程式碼即可在攔截其中獲取body且保證了controller中依舊可以再次獲取
HttpHelper.getBodyString(new RequestReaderHttpServletRequestWrapper(request));