import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;

public class QueryString {

  private StringBuilder query = new StringBuilder();
  
  public QueryString() {
  }

  public synchronized void add(String name, String value) { 
    query.append('&');
    encode(name, value);
  }
  
  private synchronized void encode(String name, String value) {
    try { 
      query.append(URLEncoder.encode(name, "UTF-8"));
      query.append('='); 
      query.append(URLEncoder.encode(value, "UTF-8"));
    } catch (UnsupportedEncodingException ex) {
      throw new RuntimeException("Broken VM does not support UTF-8");
    }
  }
  
  public synchronized String getQuery() {
    return query.toString();
  }
  
  @Override
  public String toString() {
    return getQuery();
  }
}