springboot接口如何多次获取request中的body内容

时间:2021-10-23 22:53:54

1. 概述

在使用springboot开发接口时,会将参数转化为Bean,用来进行参数的自动校验。同时也想获取request中原始body报文进行验签(防止报文传输过程中被篡改)。

因为通过将bean再转化为字符串后,body里面的报文格式、字段顺序会发生改变,就会导致验签失败。因此只能通过request来获取body里面的内容。

既想接口自动实现参数校验,同时又想获取request中的原始报文,因此我们可以通过在controller中的restful方法中,写入两个参数,获取多次request中的body内容。

那么如何实现多次读取body内容了(因为request里的body是以字节流的方式读取的,默认情况下读取一次,字节流就没有了),下面就来大致分析一下。

2 接口接收参数的其他方式

2.1 接收参数方法一

方法一、

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public R list(@RequestBody String rawMsg)

采用上述方式可以直接获得请求报文中的原始body信息,而且当body是一个json字符串时,rawMsg参数接口到的body值,不会改变json中key的顺序,即与发送方的body内容是保持一致的。这种方式可以用来对报文验签,因为被加密的字符串与发送方是保持一致的。

这种方式可以接受request里面body内容的原始格式,保持与发送方一致。

如下就可以对原始报文进行验签操作了

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// 用公钥,对原始报文进行验签,在这里如果rawMsg里面是json时,当key的顺序改变后,会验签失败,
//如此我们可以通过request来获取body里面的原始报文
boolean verifyResult = SignVerifyUtils.verifySignature(rawMsg, Constant.NPIS_PUBLIC_KEY);

2.2 接收参数方法二

方法二、

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public R list(@RequestBody @Validated ReqBean<ABCReqBean> abcReqBean)

这种接受参数的方法,可以将request里的json报文,直接转换成对应的bean对象。并且可以用来校验参数,例如某个字段是必传的、某个字段的值最大是多少等等。例如

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@NotNull(message = "日期字段不允许为空")
@Size(min = 8, max = 8, message = "日期字符串的长度必须为 8")
private String beginDate;

有没有一种方法,既能同时利用参数校验功能,又能获取原始body里的内容来进行验签呢,这时候就可以采用下面的第3中方法。

2.3 接收参数方法三

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@RequestMapping(method = {RequestMethod.POST}, value = "/dataQry")
public R list(@RequestBody @Validated ReqBean<ABCReqBean> abcReqBean,HttpServletRequest request){
}

在这里就可以通过将报文转换成abcReqBean对象,并实现接口参数的自动校验功能;同时可以利用request获取原始报文来进行验签。

注意:由于在接收参数时,HttpServletRequest只能读取一次body内容(因为是读的字节流,读完就没了),因此我们需要需要做特殊处理,

下面来看一种基于SpringBoot来解决HttpServletRequest只能读取一次的问题。

2.3.1 继承HttpServletRequestWrapper包装类,每次读取body后,再将参数写会request

为解决上述多次读取request中的body内容的问题,我们只需要将以下两个类,放到项目中即可,并通过@Component来注测为spring bean即可

继承HttpServletRequestWrapper ,实现每次读取request中的body后,在将内容写回request。

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package com.abcd.config;
import org.apache.commons.io.IOUtils;
import javax.servlet.ReadListener;
import javax.servlet.ServletInputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import java.io.*;
 
/**
 * @author:
 */
public class RequestWrapper extends HttpServletRequestWrapper {
    //参数字节数组
    private byte[] requestBody;
    //Http请求对象
    private HttpServletRequest request;
    public RequestWrapper(HttpServletRequest request) throws IOException {
        super(request);
        this.request = request;
    }
 
    /**
     * @return
     * @throws IOException
     */
    @Override
    public ServletInputStream getInputStream() throws IOException {
        /**
         * 每次调用此方法时将数据流中的数据读取出来,然后再回填到InputStream之中
         * 解决通过@RequestBody和@RequestParam(POST方式)读取一次后控制器拿不到参数问题
         */
        if (null == this.requestBody) {
            ByteArrayOutputStream baos = new ByteArrayOutputStream();
            IOUtils.copy(request.getInputStream(), baos);
            this.requestBody = baos.toByteArray();
        }
 
        final ByteArrayInputStream bais = new ByteArrayInputStream(requestBody);
        return new ServletInputStream() {
 
            @Override
            public boolean isFinished() {
                return false;
            }
 
            @Override
            public boolean isReady() {
                return false;
            }
 
            @Override
            public void setReadListener(ReadListener listener) {
 
            }
 
            @Override
            public int read() {
                return bais.read();
            }
        };
    }
 
    public byte[] getRequestBody() {
        return requestBody;
    }
 
    @Override
    public BufferedReader getReader() throws IOException {
        return new BufferedReader(new InputStreamReader(this.getInputStream()));
    }
}

2.3.2 将包装类加入过滤器链

回写参数的包装类写好之后接下来就是加入过滤器链之中,如下:

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package com.abcd.config;
import org.springframework.stereotype.Component;
import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import java.io.IOException;
/**
 * @author:
 */
@Component
@WebFilter(filterName = "channelFilter", urlPatterns = {"/*"})
public class ChannelFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
    }
 
    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) {
        try {
            ServletRequest requestWrapper = null;
            if (request instanceof HttpServletRequest) {
                requestWrapper = new RequestWrapper((HttpServletRequest) request);
            }
            if (requestWrapper == null) {
                chain.doFilter(request, response);
            } else {
                chain.doFilter(requestWrapper, response);
            }
        } catch (IOException e) {
            e.printStackTrace();
        } catch (ServletException e) {
            e.printStackTrace();
        }
    }
 
    @Override
    public void destroy() {
    }
}

解决springboot v2.2以上重复读取request body内容问题

一、需求

项目有两个场景会用到从Request的Body中读取内容。

1、打印请求日志

2、提供Api接口,在api方法执行前,从Request Body中读取参数进行验签,验签通过后在执行api方法

二、解决方案

2.1 自定义RequestWrapper

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public class MyRequestWrapper extends HttpServletRequestWrapper {
    private final String body;
    public MyRequestWrapper(HttpServletRequest request) throws IOException {
        super(request);
        this.body = RequestReadUtils.read(request);
    }
    public String getBody() {
        return body;
    }
    @Override
    public ServletInputStream getInputStream() throws IOException {
        final ByteArrayInputStream bais = new ByteArrayInputStream(body.getBytes());
        
        return new ServletInputStream() {
            ...略
        };
    }
    @Override
    public BufferedReader getReader() throws IOException {
        return new BufferedReader(new InputStreamReader(this.getInputStream()));
    }
}

RequestReadUtils(网上抄的)

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private static final int BUFFER_SIZE = 1024 * 8;
     
    public static String read(HttpServletRequest request) throws IOException {
        BufferedReader bufferedReader = request.getReader();
        for (Enumeration<String> iterator = request.getHeaderNames(); iterator.hasMoreElements();) {
            String type = iterator.nextElement();
            System.out.println(type+" = "+request.getHeader(type));
        }
        System.out.println();
        StringWriter writer = new StringWriter();
        write(bufferedReader,writer);
        return writer.getBuffer().toString();
    }
 
    public static long write(Reader reader,Writer writer) throws IOException {
        return write(reader, writer, BUFFER_SIZE);
    }
 
    public static long write(Reader reader, Writer writer, int bufferSize) throws IOException
    {
        int read;
        long total = 0;
        char[] buf = new char[bufferSize];
        while( ( read = reader.read(buf) ) != -1 ) {
            writer.write(buf, 0, read);
            total += read;
        }
        return total;
    }

2.2 定义Filter

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@WebFilter
public class TestFilter implements Filter{
 @Override
 public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain chain){
  HttpServletRequest request = (HttpServletRequest) servletRequest;
  HttpServletResponse response = (HttpServletResponse) servletResponse;
  
  MyRequestWrapper wrapper = WebUtils.getNativeRequest(request, MyRequestWrapper.class);
  chain.doFilter(wrapper == null ? new MyRequestWrapper(request) :wrapper,servletRequest);
 }
}

三、遇到问题

使用的SpringBoot v2.1.x版本

1、Form提交无问题

2、获取RequestBody无问题

使用SpringBoot v2.2.0以上版本(包括v2.3.x)

1、Form提交无法获取参数

2、获取RequestBody无问题

四、问题排查

经过排查,v2.2.x对比v2.1.x的不同在于一下代码差异:

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BufferedReader bufferedReader = request.getReader();
-----------------
char[] buf = new char[bufferSize];
while( ( read = reader.read(buf) ) != -1 ) {
    writer.write(buf, 0, read);
    total += read;
}

当表单提交时

1、v2.1.x无法read到内容,读取结果为-1

2、v2.2.x、v2.3.x能够读取到内容

当表单提交时(x-www-form-urlencoded),inputStream读取一次后后续不会触发wrapper的getInputStream操作,所以Controller无法获取到参数。

解决方案

MyRequestWrapper改造

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public class MyRequestWrapper extends HttpServletRequestWrapper {
    private final String body;
    public MyRequestWrapper(HttpServletRequest request) throws IOException {
        super(request);
        this.body = getBodyString(request);
    }
    public String getBody() {
        return body;
    }
    
    public String getBodyString(final HttpServletRequest request) throws IOException {
        String contentType = request.getContentType();
        String bodyString = "";
        StringBuilder sb = new StringBuilder();
        if (StringUtils.isNotBlank(contentType) && (contentType.contains("multipart/form-data") || contentType.contains("x-www-form-urlencoded"))) {
            Map<String, String[]> parameterMap = request.getParameterMap();
            for (Map.Entry<String, String[]> next : parameterMap.entrySet()) {
                String[] values = next.getValue();
                String value = null;
                if (values != null) {
                    if (values.length == 1) {
                        value = values[0];
                    } else {
                        value = Arrays.toString(values);
                    }
                }
                sb.append(next.getKey()).append("=").append(value).append("&");
            }
            if (sb.length() > 0) {
                bodyString = sb.toString().substring(0, sb.toString().length() - 1);
            }
            return bodyString;
        } else {
            return IOUtils.toString(request.getInputStream());
        }
    }
    @Override
    public ServletInputStream getInputStream() throws IOException {
        final ByteArrayInputStream bais = new ByteArrayInputStream(body.getBytes());
        
        return new ServletInputStream() {
            @Override
            public boolean isFinished() {
                return false;
            }
            @Override
            public boolean isReady() {
                return false;
            }
            @Override
            public int read() {
                return bais.read();
            }
            @Override
            public void setReadListener(ReadListener readListener) {
            }
        };
    }
    @Override
    public BufferedReader getReader() throws IOException {
        return new BufferedReader(new InputStreamReader(this.getInputStream()));
    }
}

以上为个人经验,希望能给大家一个参考,也希望大家多多支持服务器之家。

原文链接:https://blog.csdn.net/litlit023/article/details/111874579