SpringBoot过滤器获取响应的参数

╰+攻爆jí腚メ 2024-04-24 14:50 87阅读 0赞

#### 一、背景 ####

在项目开发过程中，需要对于某些接口统一处理。  
这时候就需要获取响应的报文，再对获取的报文进行统一处理。

#### 二、了解过滤器 ####

首先了解一下过滤器拦截器的区别：  
[JAVA中的拦截器、过滤器：https://blog.csdn.net/qq\_38254635/article/details/131201519][JAVA_https_blog.csdn.net_qq_38254635_article_details_131201519]

#### 三、代码 ####

新建 WebResponseWrapper.java  
重写 HttpServletResponseWrapper，处理json报文请求

package com.config.filter;
    
    import javax.servlet.ServletOutputStream;
    import javax.servlet.WriteListener;
    import javax.servlet.http.HttpServletResponse;
    import javax.servlet.http.HttpServletResponseWrapper;
    import java.io.ByteArrayOutputStream;
    import java.io.IOException;
    import java.io.OutputStreamWriter;
    import java.io.PrintWriter;
    import java.io.UnsupportedEncodingException;
    
    public class WebResponseWrapper extends HttpServletResponseWrapper {
        
        private ByteArrayOutputStream buffer = null;
        private ServletOutputStream out = null;
        private PrintWriter writer = null;
    
        public WebResponseWrapper(HttpServletResponse response) throws IOException {
        
            super(response);
            buffer = new ByteArrayOutputStream();
            out = new WrapperOutputStream(buffer);
            writer = new PrintWriter(new OutputStreamWriter(buffer,this.getCharacterEncoding()));
        }
    
        @Override
        public ServletOutputStream getOutputStream() throws IOException {
        
            return out;
        }
    
        @Override
        public PrintWriter getWriter() throws UnsupportedEncodingException {
        
            return writer;
        }
    
        @Override
        public void flushBuffer() throws IOException {
        
            if (out != null) {
        
                out.flush();
            }
            if (writer != null) {
        
                writer.flush();
            }
        }
    
        @Override
        public void reset() {
        
            buffer.reset();
        }
    
        public byte[] getResponseData() throws IOException {
        
            flushBuffer();
            return buffer.toByteArray();
        }
    
        private class WrapperOutputStream extends ServletOutputStream {
        
            private ByteArrayOutputStream bos = null;
    
            public WrapperOutputStream(ByteArrayOutputStream stream)
                    throws IOException {
        
                bos = stream;
            }
    
            @Override
            public void write(int b) throws IOException {
        
                bos.write(b);
            }
    
            @Override
            public void write(byte[] b) throws IOException {
        
                bos.write(b, 0, b.length);
            }
    
            @Override
            public boolean isReady() {
        
                return false;
            }
    
            @Override
            public void setWriteListener(WriteListener writeListener) {
        
    
            }
        }
    
    }

新建WebResponseFilter.java，响应过滤器处理参数，加密、字符串替、添加响应参数等等。

package com.config.filter;
    
    import com.Utils;
    import org.springframework.stereotype.Component;
    import javax.servlet.Filter;
    import javax.servlet.FilterChain;
    import javax.servlet.FilterConfig;
    import javax.servlet.ServletException;
    import javax.servlet.ServletRequest;
    import javax.servlet.ServletResponse;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    import java.io.IOException;
    import java.io.PrintWriter;
    
    @Component
    public class WebResponseFilter implements Filter {
        
    
        @Override
        public void init(FilterConfig filterConfig) throws ServletException {
        
    
        }
    
        @Override
        public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        
            HttpServletRequest httpRequest = (HttpServletRequest) request;
            HttpServletResponse httpResponse = (HttpServletResponse) response;
            if(checkPath(httpRequest.getRequestURI())){
        
                chain.doFilter(httpRequest, httpResponse);
            } else {
        
                response.setContentType("application/json; charset=utf-8");
                response.setCharacterEncoding("UTF-8");
                WebResponseWrapper webResponseWrapper = new WebResponseWrapper((HttpServletResponse) response);
                chain.doFilter(request, webResponseWrapper);
                byte[] resData = webResponseWrapper.getResponseData();
                PrintWriter out = response.getWriter();
    			String encrypt = Utils.handleResponse(new String(resData, "UTF-8"));
    			out.print(encrypt.replaceAll("[\\s*\t\n\r]", ""));
                out.flush();
                out.close();
            }
        }
    
        private boolean checkPath(String url){
        
            if(!"on".equals(ENCRYPT_SWITCH)) return true;
            for (String path : RESPONSE_LIST) {
        
                if(url.contains(path)) return true;
            }
            return false;
        }
    
        @Override
        public void destroy() {
        
    
        }
    
    }

说明：  
ENCRYPT\_SWITCH：开关配置  
RESPONSE\_LIST：忽略处理路径配置，如一些导出的操作。  
Utils.handleResponse()：需要对报文进行的处理操作。

相关链接：  
[SpringBoot过滤器获取请求的参数：https://blog.csdn.net/qq\_38254635/article/details/136041159][SpringBoot_https_blog.csdn.net_qq_38254635_article_details_136041159]  
[JAVA中的拦截器、过滤器：https://blog.csdn.net/qq\_38254635/article/details/131201519][JAVA_https_blog.csdn.net_qq_38254635_article_details_131201519]

OK，就这些吧。

有什么不对的还望指正，书写不易，觉得有帮助就点个赞吧！☺☺☺

[JAVA_https_blog.csdn.net_qq_38254635_article_details_131201519]: https://blog.csdn.net/qq_38254635/article/details/131201519
[SpringBoot_https_blog.csdn.net_qq_38254635_article_details_136041159]: https://blog.csdn.net/qq_38254635/article/details/136041159