Package javax.servlet.http

Class HttpUtils

java.lang.Object
javax.servlet.http.HttpUtils
public class HttpUtils extends Object

  • Constructor Details

    • HttpUtils

      public HttpUtils()
      Constructs an empty HttpUtils object.

  • Method Details

    • parseQueryString

      public static Hashtable<String,String[]> parseQueryString(String s)
      Parses a query string passed from the client to the server and builds a HashTable object with key-value pairs. The query string should be in the form of a string packaged by the GET or POST method, that is, it should have key-value pairs in the form key=value, with each pair separated from the next by a & character.

      A key can appear more than once in the query string with different values. However, the key appears only once in the hashtable, with its value being an array of strings containing the multiple values sent by the query string.

      The keys and values in the hashtable are stored in their decoded form, so any + characters are converted to spaces, and characters sent in hexadecimal notation (like %xx) are converted to ASCII characters.

      Parameters:
      s - a string containing the query to be parsed
      Returns:
      a HashTable object built from the parsed key-value pairs
      Throws:
      IllegalArgumentException - if the query string is invalid

    • parsePostData

      public static Hashtable<String,String[]> parsePostData(int len, ServletInputStream in)
      Parses data from an HTML form that the client sends to the server using the HTTP POST method and the application/x-www-form-urlencoded MIME type.

      The data sent by the POST method contains key-value pairs. A key can appear more than once in the POST data with different values. However, the key appears only once in the hashtable, with its value being an array of strings containing the multiple values sent by the POST method.

      The keys and values in the hashtable are stored in their decoded form, so any + characters are converted to spaces, and characters sent in hexadecimal notation (like %xx) are converted to ASCII characters.

      Parameters:
      len - an integer specifying the length, in characters, of the ServletInputStream object that is also passed to this method
      in - the ServletInputStream object that contains the data sent from the client
      Returns:
      a HashTable object built from the parsed key-value pairs
      Throws:
      IllegalArgumentException - if the data sent by the POST method is invalid

    • getRequestURL

      public static StringBuffer getRequestURL(HttpServletRequest req)
      Reconstructs the URL the client used to make the request, using information in the HttpServletRequest object. The returned URL contains a protocol, server name, port number, and server path, but it does not include query string parameters.

      Because this method returns a StringBuffer, not a string, you can modify the URL easily, for example, to append query parameters.

      This method is useful for creating redirect messages and for reporting errors.

      Parameters:
      req - a HttpServletRequest object containing the client's request
      Returns:
      a StringBuffer object containing the reconstructed URL