org.springframework.web.filter.TraceFilter Maven / Gradle / Ivy

package org.springframework.web.filter;

import java.io.IOException;
import java.net.InetAddress;
import java.net.UnknownHostException;

import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.util.StringUtils;

/**
 * @see org.springframework.session.web.http.SessionRepositoryFilter#DEFAULT_ORDER
 * @see org.springframework.boot.autoconfigure.security.SecurityProperties#DEFAULT_FILTER_ORDER
 */
public class TraceFilter extends OncePerRequestFilter {
  private static final String DEFAULT_USER_HEADER_NAME = "X-Trace-User";
  private static final String DEFAULT_SESSION_HEADER_NAME = "X-Trace-Session";
  private static final String DEFAULT_HOSTNAME_HEADER_NAME = "X-Trace-Hostname";

  private String userHeaderName = DEFAULT_USER_HEADER_NAME;
  private String sessionHeaderName = DEFAULT_SESSION_HEADER_NAME;
  private String hostnameHeaderName = DEFAULT_HOSTNAME_HEADER_NAME;

  private String hostname;

  public TraceFilter() {
    try {
      this.hostname = InetAddress.getLocalHost().getHostName();
    }
    catch (UnknownHostException e) {
      if (logger.isWarnEnabled()) {
        logger.warn(e, e);
      }
    }
  }

  @Override
  protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) throws ServletException, IOException {
    addUserHeader(request, response);
    addSessionHeader(request, response);
    addHostnameHeader(request, response);
    filterChain.doFilter(request, response);
  }

  private void addUserHeader(HttpServletRequest request, HttpServletResponse response) {
    String user = null;
    try {
      user = request.getRemoteUser();
    }
    catch (Exception e) {
      if (logger.isErrorEnabled()) {
        logger.error(e, e);
      }
    }
    if (!response.containsHeader(this.userHeaderName) && StringUtils.hasText(user)) {
      response.addHeader(this.userHeaderName, user);
    }
  }

  private void addSessionHeader(HttpServletRequest request, HttpServletResponse response) {
    String session = null;
    try {
      session = request.getRequestedSessionId();
    }
    catch (Exception e) {
      if (logger.isErrorEnabled()) {
        logger.error(e, e);
      }
    }
    if (!response.containsHeader(this.sessionHeaderName) && StringUtils.hasText(session)) {
      response.addHeader(this.sessionHeaderName, session);
    }
  }

  private void addHostnameHeader(HttpServletRequest request, HttpServletResponse response) {
    if (!response.containsHeader(this.hostnameHeaderName) && StringUtils.hasText(this.hostname)) {
      response.addHeader(this.hostnameHeaderName, this.hostname);
    }
  }

  public String getUserHeaderName() {
    return userHeaderName;
  }

  public void setUserHeaderName(String userHeaderName) {
    this.userHeaderName = userHeaderName;
  }

  public String getSessionHeaderName() {
    return sessionHeaderName;
  }

  public void setSessionHeaderName(String sessionHeaderName) {
    this.sessionHeaderName = sessionHeaderName;
  }

  public String getHostnameHeaderName() {
    return hostnameHeaderName;
  }

  public void setHostnameHeaderName(String hostnameHeaderName) {
    this.hostnameHeaderName = hostnameHeaderName;
  }

  public String getHostname() {
    return hostname;
  }

  public void setHostname(String hostname) {
    this.hostname = hostname;
  }
}