package com.atlassian.pageobjects.util;
   
   import java.util.HashMap;
   import java.util.Map;
   
   import org.apache.commons.lang.Validate;
   
   
   /**
   * Helper class for building a query string
   */
  public class QueryStringBuilder
  {
  
      private final Map<String, String> params = new HashMap<String, String>();
  
  
      public QueryStringBuilder(String... params)
      {
          Validate.isTrue(params.length % 2 == 0, "Must be an even number of parameters");
  
          for (int i = 0; i < params.length; i += 2)
          {
              this.params.put(params[i], params[i + 1]);
          }
      }
  
      public QueryStringBuilder add(String key, String value)
      {
          params.put(key, value);
          return this;
      }
  
      public int size()
      {
          return params.size();
      }
  
      public String toString()
      {
          StringBuffer result = new StringBuffer();
  
          for (String key : params.keySet())
          {
              if (result.length() > 0)
              {
                  result.append("&");
              }
  
              result.append(key).append("=").append(params.get(key));
          }
  
          return result.toString();
      }
  
  }