request.getInputStream()只能够读取一次，但是在实际的开发中往往需要多次读取。这样就需要我们将流写入进去，提供后续使用。方法可能有很多，
这里提供其中一种！
1：创建HttpHelper类获取流中的数据。
public class HttpHelper {
/**
* 获取请求Body
* @param request
* @return
*/
private static Logger
logger = LoggerFactory.
getLogger(HttpHelper.
class);
public static String getBodyString(ServletRequest request) {
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) {
logger.warn(
"getBodyString出现问题！");
}
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();
}
}
2：重写HttpServletRequestWrapper类public class BodyReaderHttpServletRequestWrapper
extends HttpServletRequestWrapper {
private final byte[]
body;
public BodyReaderHttpServletRequestWrapper(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) {
}
};
}
}
3：在过滤器中加入如下代码@Configuration
public class CorsConfig
extends OncePerRequestFilter {
protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain)
throws ServletException, IOException {
// 防止流读取一次后就没有了, 所以需要将流继续写出去，提供后续使用
ServletRequest requestWrapper =
new BodyReaderHttpServletRequestWrapper(request);
String json = HttpHelper.
getBodyString(requestWrapper);
filterChain.doFilter(requestWrapper, response);
}
}
这里一定要注意返回的request必须是我们重写之后的，否则还是会出现问题！
