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<TITLE>Getting the Requesting URL in a Servlet (Java Developers Almanac Example)
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<A HREF="../javax.servlet/pkg.html">javax.servlet</A><font color="#666666" class="xsmall-font">
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<B><A HREF="../javax.servlet/pkg.html#Requests">Requests</A></B><font color="#666666" class="xsmall-font">
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<h3>e1042. Getting the Requesting URL in a Servlet</h3>
A servlet container breaks up the requesting URL into convenient
components for the servlet. The standard API does not require the
original requesting URL to be saved and therefore it is not possible
to get the requesting URL exactly as the client sent it. However, a
functional equivalent of the original URL can be constructed. The
following example assumes the original requesting URL is:
<pre> http://hostname.com/mywebapp/servlet/MyServlet/a/b;c=123?d=789
</pre>
The most convenient method for reconstructing the original URL is to
use <code>ServletRequest.getRequestURL()</code>, which returns all but the
query string. Adding the query string reconstructs an equivalent of
the original requesting URL:
<pre> // http://hostname.com/mywebapp/servlet/MyServlet/a/b;c=123?d=789
public static String getUrl(HttpServletRequest req) {
String reqUrl = req.getRequestURL().toString();
String queryString = req.getQueryString(); // d=789
if (queryString != null) {
reqUrl += "?"+queryString;
}
return reqUrl;
}
</pre>
If the hostname is not needed, <code>ServletRequest.getRequestURI()</code>
should be used:
<pre> // /mywebapp/servlet/MyServlet/a/b;c=123?d=789
public static String getUrl2(HttpServletRequest req) {
String reqUri = req.getRequestURI().toString();
String queryString = req.getQueryString(); // d=789
if (queryString != null) {
reqUri += "?"+queryString;
}
return reqUri;
}
</pre>
The original URL can also be reconstructed from more basic components
available to the servlet:
<pre> // http://hostname.com:80/mywebapp/servlet/MyServlet/a/b;c=123?d=789
public static String getUrl3(HttpServletRequest req) {
String scheme = req.getScheme(); // http
String serverName = req.getServerName(); // hostname.com
int serverPort = req.getServerPort(); // 80
String contextPath = req.getContextPath(); // /mywebapp
String servletPath = req.getServletPath(); // /servlet/MyServlet
String pathInfo = req.getPathInfo(); // /a/b;c=123
String queryString = req.getQueryString(); // d=789
// Reconstruct original requesting URL
String url = scheme+"://"+serverName+":"+serverPort+contextPath+servletPath;
if (pathInfo != null) {
url += pathInfo;
}
if (queryString != null) {
url += "?"+queryString;
}
return url;
}
</pre>
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<b>Related Examples</b></font></td>
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e1040. <a class="eglink" href="GetReqParam.html?l=rel">
Getting a Request Parameter in a Servlet
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e1041. <a class="eglink" href="NoMulti.html?l=rel">
Preventing Concurrent Requests to a Servlet
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e1043. <a class="eglink" href="GetHeaders.html?l=rel">
Getting a Request Header in a Servlet
</a>
<br>
e1044. <a class="eglink" href="DoHead.html?l=rel">
Processing a HEAD Request in a Servlet
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e1045. <a class="eglink" href="GetClientInfo.html?l=rel">
Getting the Client's Address in a Servlet
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