ServletUtilities.java Utility class that, among other things, contains the static filter method that replaces special HTML characters with their HTML character entities. #Programming Code Examples #Java/J2EE/J2ME #Servlet

ServletUtilities.java  Utility class that, among other things, contains the static filter  method that replaces special HTML characters with their HTML character entities. 

package cwp;

import javax.servlet.*;
import javax.servlet.http.*;

/** Some simple time savers. Note that most are static methods.
 *  

 *  Taken from Core Web Programming Java 2 Edition
 *  from Prentice Hall and Sun Microsystems Press,
 *  .
 *  May be freely used or adapted.
 */

public class ServletUtilities {
  public static final String DOCTYPE =
    "";

  public static String headWithTitle(String title) {
    return(DOCTYPE + "n" +
           "n" +
           "n");
  }

  /** Read a parameter with the specified name, convert it
   *  to an int, and return it. Return the designated default
   *  value if the parameter doesn't exist or if it is an
   *  illegal integer format.
  */

  public static int getIntParameter(HttpServletRequest request,
                                    String paramName,
                                    int defaultValue) {
    String paramString = request.getParameter(paramName);
    int paramValue;
    try {
      paramValue = Integer.parseInt(paramString);
    } catch(NumberFormatException nfe) { // null or bad format
      paramValue = defaultValue;
    }
    return(paramValue);
  }

  /** Given an array of Cookies, a name, and a default value,
   *  this method tries to find the value of the cookie with
   *  the given name. If there is no cookie matching the name
   *  in the array, then the default value is returned instead.
   */

  public static String getCookieValue(Cookie[] cookies,
                                      String cookieName,
                                      String defaultValue) {
    if (cookies != null) {
      for(int i=0; i<cookies .length; i++) {
        Cookie cookie = cookies[i];
        if (cookieName.equals(cookie.getName()))
          return(cookie.getValue());
      }
    }
    return(defaultValue);
  }

  /** Given an array of cookies and a name, this method tries
   *  to find and return the cookie from the array that has
   *  the given name. If there is no cookie matching the name
   *  in the array, null is returned.
   */

  public static Cookie getCookie(Cookie[] cookies,
                                 String cookieName) {
    if (cookies != null) {
      for(int i=0; i<cookies.length; i++) {
        Cookie cookie = cookies[i];
        if (cookieName.equals(cookie.getName()))
          return(cookie);
      }
    }
    return(null);
  }

  /** Given a string, this method replaces all occurrences of
   *  '' with
   *  '>', and (to handle cases that occur inside attribute
   *  values), all occurrences of double quotes with
   *  '"' and all occurrences of '&' with '&'.
   *  Without such filtering, an arbitrary string
   *  could not safely be inserted in a Web page.
   */

  public static String filter(String input) {
    StringBuffer filtered = new StringBuffer(input.length());
    char c;
    for(int i=0; i<input .length(); i++) {
      c = input.charAt(i);
      if (c == '') {
        filtered.append(">");
      } else if (c == '"') {
        filtered.append(""");
      } else if (c == '&') {
        filtered.append("&");
      } else {
        filtered.append(c);
      }
    }
    return(filtered.toString());
  }
}

Note: Brought from our old site: http://www.salearningschool.com/example_codes/ on Jan 2nd, 2017 From: http://sitestree.com/?p=10247
Categories:Programming Code Examples, Java/J2EE/J2ME, Servlet
Tags:Java/J2EE/J2MEServlet
Post Data:2017-01-02 16:04:28

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