拦截器与过滤器（二）拦截器和过滤器获取@RequestBody封装的参数

末蓝、 2023-06-19 09:45 119阅读 0赞

controller接口接收参数，一种是不带@RequestBody注解的，还有一种是有@RequestBody注解的，这两种前面讲过有很多不同点，比如接收集合，下面来看下这两种方式对于拦截器和过滤器的差别：

一、先看下不带@RequestBody注解的情况：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dfdF95X3k_size_16_color_FFFFFF_t_70][]

1、pom：

<?xml version="1.0" encoding="UTF-8"?>
    <project xmlns="http://maven.apache.org/POM/4.0.0"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
        <modelVersion>4.0.0</modelVersion>
    
        <groupId>org.example</groupId>
        <artifactId>myDemo</artifactId>
        <version>1.0-SNAPSHOT</version>
        <parent>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-parent</artifactId>
            <version>1.4.1.RELEASE</version>
        </parent>
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
            </dependency>
        </dependencies>
    
    </project>

2、dto:

package com.demo.dto;
    
    public class User {
    
        private Integer id;
        private String userName;
        private Integer age;
        //省略set、get方法
    
        @Override
        public String toString() {
            return "User{" +
                    "id=" + id +
                    ", userName='" + userName + '\'' +
                    ", age=" + age +
                    '}';
        }
    }

3、controller：

package com.demo.controller;
    
    import com.demo.dto.User;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    @RestController
    @RequestMapping("/user")
    public class UserController {
    
        @RequestMapping("/test")
        public void  test(User user){
            System.out.println("接口:"+user);
        }
    }

4、拦截器：

package com.demo.intercepter;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Component;
    import org.springframework.web.servlet.HandlerInterceptor;
    import org.springframework.web.servlet.ModelAndView;
    
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    import java.util.HashMap;
    import java.util.Map;
    @Component
    public class ActionHandle implements HandlerInterceptor {
        @Override
        public boolean preHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o) throws Exception {
            try {
    
                String requestUrl = httpServletRequest.getRequestURI();
                Map<String, String[]> originRequestMap = httpServletRequest.getParameterMap();
                Map<String,String> requestMap = new HashMap<String,String>();
                for (String key : originRequestMap.keySet()) {
                    String[] values = originRequestMap.get(key);
                    requestMap.put(key,values[0]);
                }
                System.out.println("拦截器："+requestMap);
            } catch (Exception e) {
            }
            return true;
    
        }
    
        @Override
        public void postHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, ModelAndView modelAndView) throws Exception {
    
        }
    
        @Override
        public void afterCompletion(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) throws Exception {
    
        }
    }

package com.demo.intercepter;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.boot.SpringBootConfiguration;
    import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
    import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
    
    @SpringBootConfiguration
    public class MySpringMVCConfig extends WebMvcConfigurerAdapter {
    
        @Autowired
        private ActionHandle myInterceptor;
    
        @Override
        public void addInterceptors(InterceptorRegistry registry) {
            registry.addInterceptor(myInterceptor).addPathPatterns("/**");
        }
    }

5、过滤器：

package com.demo.filter;
    import org.springframework.stereotype.Component;
    
    import javax.servlet.*;
    import java.io.IOException;
    import java.util.HashMap;
    import java.util.Map;
    
    @Component
    public class MyFilter implements Filter {
        @Override
        public void init(FilterConfig filterConfig) throws ServletException {
    
        }
    
        @Override
        public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
            Map<String, String[]> originRequestMap = request.getParameterMap();
            Map<String,String> requestMap = new HashMap<String,String>();
            for (String key : originRequestMap.keySet()) {
                String[] values = originRequestMap.get(key);
                requestMap.put(key,values[0]);
            }
            System.out.println("过滤器:"+requestMap);
            chain.doFilter(request,response);
        }
    
        @Override
        public void destroy() {
    
        }
    }

测试：访问：localhost:9999/test/user/test?id=1&userName=张三&age=6，后台打印：

![20201125095320516.png][]

二、再看下带@RequestBody注解的情况：在controller中加一个接口

@RequestMapping("/test1")
        public void  test1( @RequestBody User user){
            System.out.println("接口:"+user);
        }

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dfdF95X3k_size_16_color_FFFFFF_t_70 1][]

后台打印：

![20201125101322999.png][]

1、原因分析：普通的参数可以从request的getParameterMap中获取，而@RequestBody的参数需要从request的InputStream中获取。但是InputStream只能读取一次，如果过滤器读取了参数，后面拦截器和controler层就读取不到参数了，所以这类参数需要单独获取，可以把request封装一下，copy一份requet，一个用于在拦截器（过滤器）中读取参数，一个放行给controller使用。

2、解决方法：改造下代码：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dfdF95X3k_size_16_color_FFFFFF_t_70 2][]

（1）pom加入以下依赖：

<dependency>
                <groupId>javax.servlet</groupId>
                <artifactId>javax.servlet-api</artifactId>
                <version>3.1.0</version>
                <scope>provided</scope>
            </dependency>
            <dependency>
                <groupId>commons-beanutils</groupId>
                <artifactId>commons-beanutils</artifactId>
                <version>1.9.3</version>
            </dependency>
            <dependency>
                <groupId>org.apache.httpcomponents</groupId>
                <artifactId>httpclient</artifactId>
                <version>4.5.6</version>
            </dependency>
            <dependency>
                <groupId>org.apache.commons</groupId>
                <artifactId>commons-lang3</artifactId>
                <version>3.4</version>
            </dependency>
            <dependency>
                <groupId>javax.servlet</groupId>
                <artifactId>javax.servlet-api</artifactId>
                <version>3.1.0</version>
                <scope>provided</scope>
            </dependency>
            <dependency>
                <groupId>com.alibaba</groupId>
                <artifactId>fastjson</artifactId>
                <version>1.2.31</version>
            </dependency>

（2）新增两个util：这是关键，复制input流

package com.demo.util;
    
    import javax.servlet.ReadListener;
    import javax.servlet.ServletInputStream;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletRequestWrapper;
    import java.io.*;
    import java.net.URLDecoder;
    import java.util.*;
    
    public class BodyReaderHttpServletRequestWrapper extends HttpServletRequestWrapper {
        private Map<String, String[]> paramsMap;
    
        @Override
        public Map getParameterMap() {
            return paramsMap;
        }
    
        @Override
        public String getParameter(String name) {
            String[] values = paramsMap.get(name);
            if (values == null || values.length == 0) {
                return null;
            }
            return values[0];
        }
    
        @Override
        public String[] getParameterValues(String name) {
            return paramsMap.get(name);
        }
    
        @Override
        public Enumeration getParameterNames() {
            return Collections.enumeration(paramsMap.keySet());
        }
    
        private String getRequestBody(InputStream stream) {
            String line = "";
            StringBuilder body = new StringBuilder();
            int counter = 0;
    
            // 读取POST提交的数据内容
            BufferedReader reader = new BufferedReader(new InputStreamReader(stream));
            try {
                while ((line = reader.readLine()) != null) {
                    if (counter > 0) {
                        body.append("rn");
                    }
                    body.append(line);
                    counter++;
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
    
            return body.toString();
        }
    
        private HashMap<String, String[]> getParamMapFromPost(HttpServletRequest request) {
    
            String body = "";
            try {
                body = getRequestBody(request.getInputStream());
            } catch (IOException e) {
                e.printStackTrace();
            }
            HashMap<String, String[]> result = new HashMap<String, String[]>();
    
            if (null == body || 0 == body.length()) {
                return result;
            }
    
            return parseQueryString(body);
        }
    
        // 自定义解码函数
        private String decodeValue(String value) {
            if (value.contains("%u")) {
                return Encodes.urlDecode(value);
            } else {
                try {
                    return URLDecoder.decode(value, "UTF-8");
                } catch (UnsupportedEncodingException e) {
                    // 非UTF-8编码
                    return "";
                }
            }
        }
    
        public HashMap<String, String[]> parseQueryString(String s) {
            String valArray[] = null;
            if (s == null) {
                throw new IllegalArgumentException();
            }
            HashMap<String, String[]> ht = new HashMap<String, String[]>();
            StringTokenizer st = new StringTokenizer(s, "&");
            while (st.hasMoreTokens()) {
                String pair = (String) st.nextToken();
                int pos = pair.indexOf('=');
                if (pos == -1) {
                    continue;
                }
                String key = pair.substring(0, pos);
                String val = pair.substring(pos + 1, pair.length());
                if (ht.containsKey(key)) {
                    String oldVals[] = (String[]) ht.get(key);
                    valArray = new String[oldVals.length + 1];
                    for (int i = 0; i < oldVals.length; i++) {
                        valArray[i] = oldVals[i];
                    }
                    valArray[oldVals.length] = decodeValue(val);
                } else {
                    valArray = new String[1];
                    valArray[0] = decodeValue(val);
                }
                ht.put(key, valArray);
            }
            return ht;
        }
    
        private Map<String, String[]> getParamMapFromGet(HttpServletRequest request) {
            return parseQueryString(request.getQueryString());
        }
    
        public String getBody(){
            return new String(body);
        }
    
        // 报文
        private final byte[] body;
    
        public BodyReaderHttpServletRequestWrapper(HttpServletRequest request) throws IOException {
            super(request);
            body = readBytes(request.getInputStream());
    
            //
            /*if ("POST".equals(request.getMethod().toUpperCase())) {
                paramsMap = getParamMapFromPost(this);
            } else {
                paramsMap = getParamMapFromGet(this);
            }*/
    
        }
    
        @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 arg0) {
    
                }
            };
        }
    
        private static byte[] readBytes(InputStream in) throws IOException {
            BufferedInputStream bufin = new BufferedInputStream(in);
            int buffSize = 1024;
            ByteArrayOutputStream out = new ByteArrayOutputStream(buffSize);
    
            byte[] temp = new byte[buffSize];
            int size = 0;
            while ((size = bufin.read(temp)) != -1) {
                out.write(temp, 0, size);
            }
            bufin.close();
    
            byte[] content = out.toByteArray();
            return content;
        }
    
    }

package com.demo.util;
    
    
    import org.apache.commons.codec.DecoderException;
    import org.apache.commons.codec.binary.Base64;
    import org.apache.commons.codec.binary.Hex;
    import org.apache.commons.lang3.StringEscapeUtils;
    
    import java.io.UnsupportedEncodingException;
    import java.net.URLDecoder;
    import java.net.URLEncoder;
    
    public class Encodes {
    
        private static final String DEFAULT_URL_ENCODING = "UTF-8";
        private static final char[] BASE62 = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz".toCharArray();
    
        /**
         * Hex编码.
         */
        public static String encodeHex(byte[] input) {
            return Hex.encodeHexString(input);
        }
    
        /**
         * Hex解码.
         */
        public static byte[] decodeHex(String input) {
            try {
                return Hex.decodeHex(input.toCharArray());
            } catch (DecoderException e) {
                return null;
            }
        }
    
        /**
         * Base64编码.
         */
        public static String encodeBase64(byte[] input) {
            return Base64.encodeBase64String(input);
        }
    
        /**
         * Base64编码, URL安全(将Base64中的URL非法字符'+'和'/'转为'-'和'_', 见RFC3548).
         */
        public static String encodeUrlSafeBase64(byte[] input) {
            return Base64.encodeBase64URLSafeString(input);
        }
    
        /**
         * Base64解码.
         */
        public static byte[] decodeBase64(String input) {
            return Base64.decodeBase64(input);
        }
    
        /**
         * Base62编码。
         */
        public static String encodeBase62(byte[] input) {
            char[] chars = new char[input.length];
            for (int i = 0; i < input.length; i++) {
                chars[i] = BASE62[(input[i] & 0xFF) % BASE62.length];
            }
            return new String(chars);
        }
        /**
         * Html 转码.
         */
        public static String escapeHtml(String html) {
            return StringEscapeUtils.escapeHtml4(html);
        }
        /**
         * Html 解码.
         */
        public static String unescapeHtml(String htmlEscaped) {
            return StringEscapeUtils.unescapeHtml4(htmlEscaped);
        }
        /**
         * Xml 转码.
         */
        public static String escapeXml(String xml) {
            return StringEscapeUtils.escapeXml(xml);
        }
        /**
         * Xml 解码.
         */
        public static String unescapeXml(String xmlEscaped) {
            return StringEscapeUtils.unescapeXml(xmlEscaped);
        }
        /**
         * URL 编码, Encode默认为UTF-8.
         */
        public static String urlEncode(String part) {
            try {
                return URLEncoder.encode(part, DEFAULT_URL_ENCODING);
            } catch (UnsupportedEncodingException e) {
                //throw Exceptions.unchecked(e);
                return null;
            }
        }
        /**
         * URL 解码, Encode默认为UTF-8.
         */
        public static String urlDecode(String part) {
            try {
                return URLDecoder.decode(part, DEFAULT_URL_ENCODING);
            } catch (UnsupportedEncodingException e) {
                //throw Exceptions.unchecked(e);
                return null;
            }
        }
    }

（3）改造拦截器的获取参数部分：

package com.demo.intercepter;
    import com.alibaba.fastjson.JSON;
    import com.demo.util.BodyReaderHttpServletRequestWrapper;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Component;
    import org.springframework.web.servlet.HandlerInterceptor;
    import org.springframework.web.servlet.ModelAndView;
    
    import javax.servlet.ServletRequest;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    import java.util.HashMap;
    import java.util.Map;
    @Component
    public class ActionHandle implements HandlerInterceptor {
        @Override
        public boolean preHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o) throws Exception {
            try {
    
                String requestUrl = httpServletRequest.getRequestURI();
                ServletRequest requestWrapper = null;
                String param = "";
                String method = httpServletRequest.getMethod().toUpperCase();
                String type = httpServletRequest.getContentType();
                if ("POST".equals(method)
                        && "application/json".equalsIgnoreCase(type)) {
                    requestWrapper = new BodyReaderHttpServletRequestWrapper(httpServletRequest);
                }
    
                if (requestWrapper == null) {
                    Map<String, String[]> originRequestMap = httpServletRequest.getParameterMap();
                    Map<String,String> requestMap = new HashMap<String,String>();
                    for (String key : originRequestMap.keySet()) {
                        String[] values = originRequestMap.get(key);
                        requestMap.put(key,values[0]);
                    }
                    param = JSON.toJSONString(requestMap);
                } else {
                    param  = ((BodyReaderHttpServletRequestWrapper) requestWrapper).getBody();
                }
                System.out.println("拦截器："+param);
            } catch (Exception e) {
            }
            return true;
    
        }
    
        @Override
        public void postHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, ModelAndView modelAndView) throws Exception {
    
        }
    
        @Override
        public void afterCompletion(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) throws Exception {
    
        }
    }

（4）改造过滤器的获取参数部分：

package com.demo.filter;
    import com.alibaba.fastjson.JSON;
    import com.demo.util.BodyReaderHttpServletRequestWrapper;
    import org.springframework.stereotype.Component;
    
    import javax.servlet.*;
    import javax.servlet.http.HttpServletRequest;
    import java.io.IOException;
    import java.util.HashMap;
    import java.util.Map;
    
    @Component
    public class MyFilter implements Filter {
        @Override
        public void init(FilterConfig filterConfig) throws ServletException {
    
        }
    
        @Override
        public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
    
            ServletRequest requestWrapper = null;
            String param = "";
            if (request instanceof HttpServletRequest) {
                HttpServletRequest httpServletRequest = (HttpServletRequest) request;
                String method = httpServletRequest.getMethod().toUpperCase();
                String type = httpServletRequest.getContentType();
                if ("POST".equals(method)
                        && "application/json".equalsIgnoreCase(type)) {
                    requestWrapper = new BodyReaderHttpServletRequestWrapper(
                            (HttpServletRequest) request);
                }
            }
    
            if (requestWrapper == null) {
                Map<String, String[]> originRequestMap = request.getParameterMap();
                Map<String,String> requestMap = new HashMap<String,String>();
                for (String key : originRequestMap.keySet()) {
                    String[] values = originRequestMap.get(key);
                    requestMap.put(key,values[0]);
                }
                param = JSON.toJSONString(requestMap);
            } else {
                param  = ((BodyReaderHttpServletRequestWrapper) requestWrapper).getBody();
            }
            System.out.println("过滤器:"+param);
            //放行
            if (requestWrapper == null) {
                chain.doFilter(request, response);
            }else{
                chain.doFilter(requestWrapper, response);
            }
        }
    
        @Override
        public void destroy() {
    
        }
    }

测试：

1）带@RequestBody注解的请求：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dfdF95X3k_size_16_color_FFFFFF_t_70 3][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dfdF95X3k_size_16_color_FFFFFF_t_70 4][]

2）不带@RequestBody注解的请求：

![2020112510463912.png][]

![20201125104647705.png][]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dfdF95X3k_size_16_color_FFFFFF_t_70]: https://img-blog.csdnimg.cn/20201125095803469.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dfdF95X3k=,size_16,color_FFFFFF,t_70
[20201125095320516.png]: https://img-blog.csdnimg.cn/20201125095320516.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dfdF95X3k_size_16_color_FFFFFF_t_70 1]: https://img-blog.csdnimg.cn/20201125101254539.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dfdF95X3k=,size_16,color_FFFFFF,t_70
[20201125101322999.png]: https://img-blog.csdnimg.cn/20201125101322999.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dfdF95X3k_size_16_color_FFFFFF_t_70 2]: https://img-blog.csdnimg.cn/20201125104712601.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dfdF95X3k=,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dfdF95X3k_size_16_color_FFFFFF_t_70 3]: https://img-blog.csdnimg.cn/20201125104551815.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dfdF95X3k=,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dfdF95X3k_size_16_color_FFFFFF_t_70 4]: https://img-blog.csdnimg.cn/20201125104608587.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dfdF95X3k=,size_16,color_FFFFFF,t_70
[2020112510463912.png]: https://img-blog.csdnimg.cn/2020112510463912.png
[20201125104647705.png]: https://img-blog.csdnimg.cn/20201125104647705.png