如何记录 REST 请求和响应 JSON 对象

Question

I want to ask you if it is possible to add log system to this CORS sample without Spring (just Java 'standard' and Jersey libraries).

import java.io.IOException;
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.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet Filter implementation class CORSFilter
 */
// Enable it for Servlet 3.x implementations
/* @ WebFilter(asyncSupported = true, urlPatterns = { "/*" }) */
public class CORSFilter implements Filter {

    /**
     * Default constructor.
     */
    public CORSFilter() {
        // TODO Auto-generated constructor stub
    }

    /**
     * @see Filter#destroy()
     */
    public void destroy() {
        // TODO Auto-generated method stub
    }

    /**
     * @see Filter#doFilter(ServletRequest, ServletResponse, FilterChain)
     */
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain chain)
            throws IOException, ServletException {

        HttpServletRequest request = (HttpServletRequest) servletRequest;
        System.out.println("CORSFilter HTTP Request: " + request.getMethod());

        // Authorize (allow) all domains to consume the content
        ((HttpServletResponse) servletResponse).addHeader("Access-Control-Allow-Origin", "*");
        ((HttpServletResponse) servletResponse).addHeader("Access-Control-Allow-Methods","GET, OPTIONS, HEAD, PUT, POST");

        HttpServletResponse resp = (HttpServletResponse) servletResponse;

        // For HTTP OPTIONS verb/method reply with ACCEPTED status code -- per CORS handshake
        if (request.getMethod().equals("OPTIONS")) {
            resp.setStatus(HttpServletResponse.SC_ACCEPTED);
            return;
        }





**//String jsonRequestObject = ....;**

        // pass the request along the filter chain
        chain.doFilter(request, servletResponse);

**//String jsonResponseObject = ....;**
    }

    /**
     * @see Filter#init(FilterConfig)
     */
    public void init(FilterConfig fConfig) throws ServletException {
        // TODO Auto-generated method stub
    }

}

Answer 1

If you are using jersey implementation, then why you are implement Filter interface go with the recommended jersey filter 'ContainerRequestFilter' and 'ContainerResponseFilter'

https://javapapers.com/web-service/intercept-jax-rs-request-with-jerseycontainerrequestfilter/

Answer 2

Try to use below code

public class LogHttpInterceptor implements ClientHttpRequestInterceptor {

    final static Logger log = LoggerFactory.getLogger(LogHttpInterceptor.class);

    @Override
    public ClientHttpResponse intercept(HttpRequest request, byte[] body, ClientHttpRequestExecution execution) throws IOException {
        traceRequest(request, body);
        ClientHttpResponse response = execution.execute(request, body);
        traceResponse(response);
        return response;
    }

    private void traceRequest(HttpRequest request, byte[] body) throws IOException {
        log.trace("request begin===========================================================================");
        log.trace("URI         : {}", request.getURI());
        log.trace("Method      : {}", request.getMethod());
        log.trace("Headers     : {}", request.getHeaders() );
        log.trace("Request body: {}", new String(body, "UTF-8"));
        log.trace("request end=============================================================================");
    }

    private void traceResponse(ClientHttpResponse response) throws IOException {
        StringBuilder inputStringBuilder = new StringBuilder();
        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(response.getBody(), "UTF-8"));
        String line = bufferedReader.readLine();
        while (line != null) {
            inputStringBuilder.append(line);
            inputStringBuilder.append('\n');
            line = bufferedReader.readLine();
        }
        log.trace("response begin==========================================================================");
        log.trace("Status code  : {}", response.getStatusCode());
        log.trace("Status text  : {}", response.getStatusText());
        log.trace("Headers      : {}", response.getHeaders());
        log.trace("Response body: {}", inputStringBuilder.toString());
        log.trace("response end===========================================================================");
    }