DuplicatedKeyValidator.java :  » J2EE » Dinamica » dinamica » validators » Java Open Source

package dinamica.validators;

import java.util.HashMap;
import javax.servlet.http.HttpServletRequest;
import dinamica.*;

/**
 * Generic Validator to test if a record key is duplicated,
 * requires the following custom attributes:<br>
 * <ul>
 * <li> sql: query to find any related record. You may use field makers
 * that will be replaced by the corresponding request parameters passed
 * as a recordset to the isValid method.
 * </ul>
 * <br>If you don't use the SQL query you may use the
 * attributes shown below (not recommended).
 * <ul>
 * <li> table: name of the search table.
 * <li> column: name of the search column, also the
 * name of the parameter whose value will be used.
 * <li> varchar: true|false indicates if the column is of type varchar or alike,
 * this is used to demarcate the column search value with the proper delimiter, if any.
 * </ul>
 * <br>
 * Works only for text or numeric values, dates not allowed.
 * <br><br>
 * Creation date: 10/feb/2004<br>
 * Last Update: 10/feb/2004<br>
 * (c) 2004 Martin Cordova<br>
 * This code is released under the LGPL license<br>
 * @author Martin Cordova (dinamica@martincordova.com)
 * */

public class DuplicatedKeyValidator extends AbstractValidator
{

  /* (non-Javadoc)
   * @see dinamica.AbstractValidator#isValid(javax.servlet.http.HttpServletRequest, dinamica.Recordset, java.util.HashMap)
   */
  public boolean isValid(
    HttpServletRequest req,
    Recordset inputParams,
    HashMap<String, String> attribs)
    throws Throwable
  {
    
    boolean flag = true;
    
    //get db channel
    Db db = getDb();

    //detect if sql parameter was passed to the validator
    boolean bSql = attribs.containsKey("sql");

    String sql = "";

    if (!bSql)
    {
      //validate plugin configuration
      boolean b1 = attribs.containsKey("table");
      if (!b1)
        throw new Throwable("Bad configuration - 'table' attribute not found.");
      boolean b2 = attribs.containsKey("column");
      if (!b2)
        throw new Throwable("Bad configuration - 'column' attribute not found.");
      boolean b3 = attribs.containsKey("varchar");
      if (!b3)
        throw new Throwable("Bad configuration - 'varchar' attribute not found.");
  
      //define value enclosing character (quote or nothing)
      String delim = "";
      String isVarchar = (String)attribs.get("varchar");
      if (isVarchar.equals("true"))
        delim = "'";
  
      //get db parameters
      String table = (String)attribs.get("table");
      String col = (String)attribs.get("column");
  
      //get input value
      String value = String.valueOf(inputParams.getValue(col));
  
      //build sql
      sql = "select " + col + " from " + table + " where " + col + " = " + delim + value + delim; 
    }
    else
    {
      String query = (String)attribs.get("sql");
      sql = getResource(query);
      sql = getSQL(sql, inputParams);
    }
    
    //execute sql
    Recordset rs = db.get(sql);
    if (rs.getRecordCount()>0)
      flag = false;

    return flag;
    
  }

}