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解讀HttpServletRequestWrapper處理request數(shù)據(jù)流多次讀取問題

更新時間：2024年10月09日 10:07:26 作者：小旋風-java

在Java Web開發(fā)中,獲取HTTP請求參數(shù)是常見需求,本文詳細討論了通過POST方式獲取參數(shù)的兩種主要方法：使用request.getParameter()適用于application/x-www-form-urlencoded和multipart/form-data內(nèi)容類型；而對于application/json類型的數(shù)據(jù)

一、獲取請求參數(shù)

1、request.getParameter()
2、request.getInputStream()或request.getReader()

二、請求方contentType

1、application/x-www-form-urlencoded

@RequestMapping("/testWwwFrom")
@ResponseBody
public Book testWwwFrom(Book req, HttpServletRequest servletRequest) {
    logger.info("查詢所有1用戶信息" + JSON.toJSONString(req));
    return req;
}

2、multipart/form-data

@RequestMapping("/testFormData")
@ResponseBody
public Book testFormData(Book req, HttpServletRequest servletRequest) {
    logger.info("查詢所有1用戶信息" + JSON.toJSONString(req));
    return req;
}

3、application/json

@RequestMapping("/testJson")
@ResponseBody
public Book testJsonFrom(@RequestBody Book req, HttpServletRequest servletRequest) {
    logger.info("查詢所有1用戶信息" + JSON.toJSONString(req));
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    return req;
}

1、request.getParameter()對應(yīng)application/x-www-form-urlencoded
2、request.getInputStream()或request.getReader()對應(yīng)application/json

那么現(xiàn)在有一個這樣的需求如果是form表單就獲取formToken然后和緩存的進行CRSF防護

思路根據(jù)上面說的form表單參數(shù)獲取分為2大類。

其中request.getInputStream()獲取一次以后不能第二次獲取，以及request.getParameter()與request.getInputStream()也存在這種情況。

1、application/x-www-form-urlencoded以及multipart/form-data通過request.getParameter()獲取
2、application/json通過request.getInputStream()或request.getReader()獲取，這種要依賴HttpServletRequestWrapper

package com.study.ju.web.interceptor;
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import org.apache.commons.io.IOUtils;
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import javax.servlet.ReadListener;
import javax.servlet.ServletInputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
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/**
 * <p>https://blog.csdn.net/kaizhangzhang/article/details/97900961</p>
 *
 * 
 * @version v 0.1 2023/5/29 15:37
 */
public class ResettableServletRequestWrapper extends HttpServletRequestWrapper {
    //保存流中的數(shù)據(jù)
    private byte[] data;
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    /**
     * Constructs a request object wrapping the given request.
     *
     * @param request
     * @throws IllegalArgumentException if the request is null
     */
    public ResettableServletRequestWrapper(HttpServletRequest request) throws IOException {
        super(request);
        //從流中獲取數(shù)據(jù)
        data = IOUtils.toByteArray(request.getInputStream());
    }
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    @Override
    public ServletInputStream getInputStream() throws IOException {
        //在調(diào)用getInputStream函數(shù)時，創(chuàng)建新的流，包含原先數(shù)據(jù)流中的信息，然后返回
        return new NewServletInputStream(new ByteArrayInputStream(data));
    }
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    class NewServletInputStream extends ServletInputStream{
        private InputStream inputStream;
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        public NewServletInputStream(InputStream inputStream){
            this.inputStream = inputStream;
        }
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        @Override
        public int read() throws IOException {
            return inputStream.read();
        }
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        @Override
        public boolean isFinished() {
            return false;
        }
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        @Override
        public boolean isReady() {
            return false;
        }
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        @Override
        public void setReadListener(ReadListener readListener) {
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        }
    }
    @Override
    public BufferedReader getReader() throws IOException {
        return new BufferedReader(new InputStreamReader(this.getInputStream()));
    }
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}

package com.study.ju.web.interceptor;
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import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONArray;
import com.alibaba.fastjson.JSONObject;
import org.apache.commons.collections4.CollectionUtils;
import org.apache.commons.io.IOUtils;
import org.apache.commons.lang3.StringUtils;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
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import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.util.List;
import java.util.Map;
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/**
 * <p>form表單提交校驗token</p>
 *
 * 
 * @version v 0.1 2023/5/29 13:45
 */
public class FormSubmitTokenInterceptor implements HandlerInterceptor {
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    private String formSubmitTokenInterceptorUrls = "[\"/testJson\",\"/test/testJson\",\"/test/testWwwFrom\",\"/test/testRequestParam\"]";
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    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        String requestURI = getRequestURI(request);
        if ("POST".equals(request.getMethod().toUpperCase()) && StringUtils.isNotEmpty(formSubmitTokenInterceptorUrls)) {
            List<String> formInterceptorUrls = JSONArray.parseArray(formSubmitTokenInterceptorUrls, String.class);
            if (CollectionUtils.isNotEmpty(formInterceptorUrls)) {
                boolean contains = formInterceptorUrls.stream().anyMatch(e -> e.contains(requestURI));
                if (contains) {
                    String contentType = request.getContentType();
                    System.out.println(contentType);
                    if ("application/json".equalsIgnoreCase(contentType)) {
                        ResettableServletRequestWrapper resettableServletRequestWrapper = new ResettableServletRequestWrapper(request);
                        String bodyParam = IOUtils.toString(resettableServletRequestWrapper.getInputStream());
                        System.out.println(bodyParam);
                        if (StringUtils.isNotEmpty(bodyParam)) {
                            JSONObject jsonObject = JSONObject.parseObject(bodyParam);
                            if (jsonObject.containsKey("formToken")) {
                                String formToken = (String) jsonObject.get("formToken");
                                System.out.println("formToken:"+formToken);
                            }
                        }
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                    } else {
                        if (StringUtils.isNotEmpty(request.getParameter("formToken"))) {
                            System.out.println("formToken2:"+request.getParameter("formToken"));
                        }
                        System.out.println("name:"+request.getParameter("name"));
                    }
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                }
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            }
        }
        return true;
    }
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    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
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    }
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    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
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    }
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    /**
     * 獲取用戶請求的path，不帶contextPath
     * 如：/index.htm
     */
    public static String getRequestURI(HttpServletRequest request) {
        return StringUtils.replace(request.getRequestURI(), request.getContextPath(), "");
    }
}

web.xml放在前面

<filter>
   <filter-name>requestFilter</filter-name>
   <filter-class>com.study.ju.web.Filter.HttpServletRequestReplacedFilter</filter-class>
</filter>
<filter-mapping>
   <filter-name>requestFilter</filter-name>
   <url-pattern>/*</url-pattern>
</filter-mapping>