Class HttpUtil


  • public final class HttpUtil
    extends java.lang.Object
    Contains useful utilities for some common HTTP tasks.
    Since:
    2.1.61.
    • Method Summary

      All Methods Static Methods Concrete Methods 
      Modifier and Type Method Description
      static boolean checkFor304​(javax.servlet.http.HttpServletRequest req, java.lang.String pageName, java.util.Date lastModified)
      If returns true, then should return a 304 (HTTP_NOT_MODIFIED)
      static void clearCookie​(javax.servlet.http.HttpServletResponse response, java.lang.String cookieName)  
      static java.lang.String createETag​(java.lang.String pageName, java.util.Date lastModified)
      Creates an ETag based on page information.
      static java.lang.String getRemoteAddress​(javax.servlet.http.HttpServletRequest req)
      returns the remote address by looking into x-forwarded-for header or, if unavailable, into ServletRequest.getRemoteAddr().
      static java.lang.String guessValidURI​(java.lang.String uri)
      Attempts to form a valid URI based on the string given.
      static boolean isIPV4Address​(java.lang.String name)
      Verifies whether a String represents an IPv4 address.
      static java.lang.String retrieveCookieValue​(javax.servlet.http.HttpServletRequest request, java.lang.String cookieName)
      Attempts to retrieve the given cookie value from the request.
      static java.lang.String safeGetQueryString​(javax.servlet.http.HttpServletRequest request, java.nio.charset.Charset contentEncoding)
      Returns the query string (the portion after the question mark).
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Method Detail

      • getRemoteAddress

        public static java.lang.String getRemoteAddress​(javax.servlet.http.HttpServletRequest req)
        returns the remote address by looking into x-forwarded-for header or, if unavailable, into ServletRequest.getRemoteAddr().
        Parameters:
        req - http request
        Returns:
        remote address associated to the request.
      • retrieveCookieValue

        public static java.lang.String retrieveCookieValue​(javax.servlet.http.HttpServletRequest request,
                                                           java.lang.String cookieName)
        Attempts to retrieve the given cookie value from the request. Returns the string value (which may or may not be decoded correctly, depending on browser!), or null if the cookie is not found. The algorithm will automatically trim leading and trailing double quotes, if found.
        Parameters:
        request - The current request
        cookieName - The name of the cookie to fetch.
        Returns:
        Value of the cookie, or null, if there is no such cookie.
      • createETag

        public static java.lang.String createETag​(java.lang.String pageName,
                                                  java.util.Date lastModified)
        Creates an ETag based on page information. An ETag is unique to each page and version, so it can be used to check if the page has changed. Do not assume that the ETag is in any particular format.
        Parameters:
        pageName - The page name for which the ETag should be created.
        lastModified - The page last modified date for which the ETag should be created.
        Returns:
        A String depiction of an ETag.
      • checkFor304

        public static boolean checkFor304​(javax.servlet.http.HttpServletRequest req,
                                          java.lang.String pageName,
                                          java.util.Date lastModified)
        If returns true, then should return a 304 (HTTP_NOT_MODIFIED)
        Parameters:
        req - the HTTP request
        pageName - the wiki page name to check for
        lastModified - the last modified date of the wiki page to check for
        Returns:
        the result of the check
      • guessValidURI

        public static java.lang.String guessValidURI​(java.lang.String uri)
        Attempts to form a valid URI based on the string given. Currently it can guess email addresses (mailto:). If nothing else is given, it assumes it to be an http:// url.
        Parameters:
        uri - URI to take a poke at
        Returns:
        Possibly a valid URI
        Since:
        2.2.8
      • safeGetQueryString

        public static java.lang.String safeGetQueryString​(javax.servlet.http.HttpServletRequest request,
                                                          java.nio.charset.Charset contentEncoding)
        Returns the query string (the portion after the question mark).
        Parameters:
        request - The HTTP request to parse.
        Returns:
        The query string. If the query string is null, returns an empty string.
        Since:
        2.1.3 (method moved from WikiEngine on 2.11.0.M6)
      • isIPV4Address

        public static boolean isIPV4Address​(java.lang.String name)
        Verifies whether a String represents an IPv4 address. The algorithm is extremely efficient and does not allocate any objects.
        Parameters:
        name - the address to test
        Returns:
        the result
      • clearCookie

        public static void clearCookie​(javax.servlet.http.HttpServletResponse response,
                                       java.lang.String cookieName)