springboot添加统一拦截preHandle后RequestBody无法取值的问题

Java 02-08 16:56

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

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