Overwritting the values in the property files

Question

Hi All
I am new to reading property file in java. I am able to read the property files but it is overwritting my key/value pair.
The main thing when I am comparing the adminname which is present in the property file with the username which I am getting in the servlet request.
Its only comparing the last key/value pair ie.., adminname=ghj.
Can anyone help me regarding this...please..
i need to check whether userName(Servlet request) matches with any one of the values(abc,cde ,fgh,ghj) present in the property file.
But in my case it is only comparing the last value only.
for Eg:
admin.properties
one key and number of values. Can I do this?
adminname=abc
adminname=cde
adminname=fgh
adminname=ghj
// if they want to add or remove the admin people they are going to do it from property file which is the text file.
import java.io.*;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.RequestDispatcher;
import javax.servlet.http.*;
public class ExampleFilter implements Filter {
     private FilterConfig filterConfig=null;
     public void init(FilterConfig config) throws ServletException {
          this.filterConfig = config;
     public void destroy() {
          filterConfig = null;
     public void doFilter(ServletRequest request, ServletResponse response,
               FilterChain chain) throws IOException, ServletException {
          RequestDispatcher rd = null;
          String userInfo = "";
          String userName="";
          if (request instanceof HttpServletRequest) {
               userInfo = ((HttpServletRequest) request).getUserPrincipal()
                                  .getName();
                         String[] pieces = userInfo.split("\\\\"); // Firefox sends DOMAIN\USERNAME as UserPrincipal
                              userName = pieces[pieces.length -1]; // getting the username for which I need to perform check
       try
            Properties propertiesFile = new Properties();
            FileInputStream file =
                new FileInputStream("C:\\webapp\\WebContent\\WEB-INF\\lib\\admin.properties");
          if (file == null)
                   throw new NullPointerException("Properties file 'admin.properties' is missing in classpath.");
               propertiesFile.load(file);
                          propertiesFile.list(System.out);
                       val=propertiesFile.getProperty(adminname);       
                                             //here watever the last key/value is present in the admin.properties, I am getting it.
                         //In the above property files i will get "ghj"
                                             System.out.println("adminName In Property file:" +val);
      if(userName.equals("val"))
                                  // I NEED TO COMPARE THE USERNAME WITH THE adminname IN THE PROERTY FILE (admin.properties)
                                   // IF userName=anyone value in the property files.......... I AM FORWARDING IT TO REGULAR PAGE
                                      chain.doFilter(request, response); // if username is present in proeprty file, I need to navigate to normal pages.
                  else{
                         //IF adminname is not present i m forwarding to ERROR PAGE
                          rd = request.getRequestDispatcher("/admin/error.html");
                                       rd.forward(request, response);
           catch(Exception e)
                  e.printStackTrace();
}

Answer 1

Read the java.util.Properties API. You can't have multiple same keys. Use one key or a key with some suffix, e.g. adminname.1 and so on or so.
This has nothing to do with servlets. You've a problem with classes of java.util package, not of javax.servlet package. Use the 'New to Java' forum.