Tool to find duplicate keys and value in properties file

Question

is there a tool that tells me redundant keys and values that are there in my one or many properties file.

Answer 1

/**
 *  Purpose:  Properties doesn't detect duplicate keys.  So this exists.
 *  @author shaned
 */
package com.naehas.tests.configs;

import java.util.Properties;

import org.apache.log4j.Logger;

public class NaehasProperties extends Properties
{
   private static final long   serialVersionUID = 1L;

   private static final Logger log              = Logger.getLogger(NaehasProperties.class);

   public NaehasProperties()
   {
      super();
   }

   /**
    * @param defaults
    */
   public NaehasProperties(Properties defaults)
   {
      super(defaults);
   }

   /**
    * Overriding the HastTable put() so we can check for duplicates
    * 
    */
   public synchronized Object put(Object key, Object value)
   {
      // Have we seen this key before?
      //
      if (get(key) != null)
      {
         StringBuffer message = new StringBuffer("Duplicate key found: " + key + " with value: " + value);
         message.append(". Original value is: " + (String) get(key));

         log.error(message.toString());

         // Setting key to null will generate an exception and cause an exit.
         // Can not change the signature by adding a throws as it's not compatible
         // with HashTables put().
         //
         // If you commented out this line, you will see all the occurrences of the duplicate key
         // as the put will overwrite the past encounter.
         //
         key = null;
      }

      return super.put(key, value);
   }
}