package pl.edu.icm.saos.common.http;
import javax.servlet.http.HttpServletRequest;
import com.google.common.base.Preconditions;
/**
* Utility class with methods facilitating extracting various info from an {@link HttpServletRequest}
*
* @author Łukasz Dumiszewski
*/
public final class HttpServletRequestUtils {
private HttpServletRequestUtils() {
throw new IllegalStateException("may not be instantiated");
}
/**
* Returns client ip. Looks for X-FORWARDED-FOR header and if it is set, returns its value.
* If there is no X-FORWARDED-FOR header set then returns {@link HttpServletRequest#getRemoteAddr()}
*/
public static String extractClientIp(HttpServletRequest request) {
Preconditions.checkNotNull(request);
String ipAddress = request.getHeader("X-FORWARDED-FOR");
if (ipAddress == null) {
ipAddress = request.getRemoteAddr();
}
return ipAddress;
}
/**
* Returns scheme (like http, https etc) provided by a client. Looks for X-FORWARDED-PROTO header and if it is set, returns its value.
* If there is no X-FORWARDED-PROTO header set then returns {@link HttpServletRequest#getScheme()}
*/
public static String extractScheme(HttpServletRequest request) {
Preconditions.checkNotNull(request);
String scheme = request.getHeader("X-FORWARDED-PROTO");
if (scheme == null) {
scheme = request.getScheme();
}
return scheme;
}
/**
* Returns host (like saos.org.pl). Looks for X-FORWARDED-HOST header and if it is set, returns its value.
* If there is no X-FORWARDED-HOST header set then returns {@link HttpServletRequest#getServerName()}
*/
public static String extractHost(HttpServletRequest request) {
Preconditions.checkNotNull(request);
String host = request.getHeader("X-FORWARDED-HOST");
if (host == null) {
host = request.getServerName();
}
return host;
}
/**
* Returns server port provided by a client. Looks for X-FORWARDED-PORT header and if it is set, returns its value.
* If there is no X-FORWARDED-PORT header set then returns {@link HttpServletRequest#getServerPort()()}
*/
public static int extractServerPort(HttpServletRequest request) {
Preconditions.checkNotNull(request);
int port = request.getIntHeader("X-FORWARDED-PORT");
if (port == -1) {
port = request.getServerPort();
}
return port;
}
/**
* Returns base url sent by the client.
* The url consists of: <br/>
* <ul>
* <li> scheme - {@link #extractClientScheme(HttpServletRequest)} </li>
* <li> host - {@link #extractClientHost(HttpServletRequest)} </li>
* <li> port - {@link #extractServerPort(HttpServletRequest)} </li>
* </ul>
*/
public static String constructRequestBaseUrl(HttpServletRequest request) {
StringBuilder path = new StringBuilder();
String scheme = extractScheme(request);
int port = extractServerPort(request);
path.append (scheme);
path.append ("://");
path.append (extractHost(request));
if (!isDefaultPort(scheme, port)) {
path.append (':');
path.append (port);
}
return path.toString();
}
/**
* Returns url sent by the client (without parameters).
* The url consists of: <br/>
* <ul>
* <li> scheme - {@link #extractClientScheme(HttpServletRequest)} </li>
* <li> host - {@link #extractClientHost(HttpServletRequest)} </li>
* <li> port - {@link #extractServerPort(HttpServletRequest)} </li>
* <li> urlPath - {@link HttpServletRequest#getRequestURI()} </li>
* </ul>
*/
public static String constructRequestUrl(HttpServletRequest request) {
StringBuilder url = new StringBuilder();
url.append(constructRequestBaseUrl(request));
String urlPath = request.getRequestURI();
url.append(urlPath);
return url.toString();
}
/**
* Returns url sent by the client with parameters.
* The url consists of: <br/>
* <ul>
* <li> scheme - {@link #extractClientScheme(HttpServletRequest)} </li>
* <li> host - {@link #extractClientHost(HttpServletRequest)} </li>
* <li> port - {@link #extractServerPort(HttpServletRequest)} </li>
* <li> urlPath - {@link HttpServletRequest#getRequestURI()} </li>
* <li> queryString - {@link HttpServletRequest#getQueryString()} </li>
* </ul>
*/
public static String constructRequestUrlWithParameters(HttpServletRequest request) {
StringBuilder path = new StringBuilder();
String url = constructRequestUrl(request);
String queryString = request.getQueryString();
path.append(url);
if (queryString != null) {
path.append("?").append(queryString);
}
return path.toString();
}
/**
* Is the given port a default port for the given scheme
*/
public static boolean isDefaultPort(String scheme, int port) {
Preconditions.checkNotNull(scheme);
return ((scheme.equals("http") && port == 80) || (scheme.equals("https") && port == 443));
}
}