springboot添加统一拦截preHandle后RequestBody无法取值的问题
在最近的springboot项目中，需要添加一个统一的拦截器来对body中的值进行内容校验、加密校验等。使用的是spring的HandlerInterceptor来处理，在HandlerInterceptor里通过request.getInputStream()的方式来获取，处理成功后，调试却发现controller层里面使用的@RequestBody获取不到值了，报错了！Required request body is missing
经过网上查询发现原因：request.getInputStream()只能读取一次，所以当使用拦截器时，controller已经不能获取body中的参数。所以需要增加一个过滤器来解决，使流可以重复读取。解决代码步骤如下
①写一个类RequestWrapper，继承HttpServletRequestWrapper
package cn.cloud.tcp.utils;
import javax.servlet.ReadListener;
import javax.servlet.ServletInputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import java.io.*;
public class RequestWrapper extends HttpServletRequestWrapper {
private final String body;
public RequestWrapper(HttpServletRequest request) {
super(request);
StringBuilder stringBuilder = new StringBuilder();
BufferedReader bufferedReader = null;
InputStream inputStream = null;
try {
inputStream = request.getInputStream();
if (inputStream != null) {
bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
char[] charBuffer = new char[128];
int bytesRead = -1;
while ((bytesRead = bufferedReader.read(charBuffer)) > 0) {
stringBuilder.append(charBuffer, 0, bytesRead);
}
} else {
stringBuilder.append("");
}
} catch (IOException ex) {
} finally {
if (inputStream != null) {
try {
inputStream.close();
}
catch (IOException e) {
e.printStackTrace();
}
}
if (bufferedReader != null) {
try {
bufferedReader.close();
}
catch (IOException e) {
e.printStackTrace();
}
}
}
body = stringBuilder.toString();
}
@Override
public ServletInputStream getInputStream() throws IOException {
final ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(body.getBytes());
ServletInputStream servletInputStream = new ServletInputStream() {
@Override
public boolean isFinished() {
return false;
}
@Override
public boolean isReady() {
return false;
}
@Override
public void setReadListener(ReadListener readListener) {
}
@Override
public int read() throws IOException {
return byteArrayInputStream.read();
}
};
return servletInputStream;
}
@Override
public BufferedReader getReader() throws IOException {
return new BufferedReader(new InputStreamReader(this.getInputStream()));
}
public String getBody() {
return this.body;
}
}
②拦截器层面使用并处理逻辑
package cn.cloud.tcp.web.interceptor;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.Map;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import cn.cloud.tcp.utils.RequestWrapper;
import org.springframework.web.servlet.HandlerInterceptor;
import com.alibaba.fastjson.JSON;
import cn.hutool.core.util.StrUtil;
public class SignatureInterceptor implements HandlerInterceptor {
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
RequestWrapper requestWrapper = new RequestWrapper(request);
String body = requestWrapper.getBody();
Map<String, String> params = JSON.parseObject(body, Map.class);
String appKey = params.get("appKey");
String timestamp = params.get("timestamp");
String signature = params.get("signature");
response.addHeader("Content-Type", "application/json;charset=UTF-8");
if (StrUtil.isBlank(appKey) || StrUtil.isBlank(timestamp) || StrUtil.isBlank(signature)) {
// 处理逻辑
return false;
}
return true;
}
}
③过滤器Filter，用来把request传递下去
package cn.cloud.tcp.utils;
import org.springframework.stereotype.Component;
import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import java.io.IOException;
@Component
@WebFilter(urlPatterns = "/*",filterName = "ChannelFilter")
public class ChannelFilter implements Filter {
@Override
public void init(FilterConfig filterConfig) throws ServletException {
}
@Override
public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
ServletRequest requestWrapper = null;
if(servletRequest instanceof HttpServletRequest) {
requestWrapper = new RequestWrapper((HttpServletRequest) servletRequest);
}
if(requestWrapper == null) {
filterChain.doFilter(servletRequest, servletResponse);
} else {
filterChain.doFilter(requestWrapper, servletResponse);
}
}
@Override
public void destroy() {
}
}
④在启动类中注册拦截器
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.servlet.MultipartConfigFactory;
import org.springframework.boot.web.servlet.ServletComponentScan;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
@SpringBootApplication
@ServletComponentScan //注册过滤器注解
@Configuration
public class WebApplication {
public static void main(String[] args) {
SpringApplication.run(WebApplication.class, args);
}
}
经测试，问题解决