Interface TypeHandlerCallback

Using this interface, you can implement a type handler that will perform customized processing before parameters are set on a PreparedStatement and after values are retrieved from a ResultSet. Using a custom type handler you can extend the framework to handle types that are not supported, or handle supported types in a different way. For example, you might use a custom type handler to implement proprietary BLOB support (e.g. Oracle), or you might use it to handle booleans using "Y" and "N" instead of the more typical 0/1.

EXAMPLE

Here's a simple example of a boolean handler that uses "Yes" and "No".

 public class YesNoBoolTypeHandlerCallback implements TypeHandlerCallback {
 

   private static final String YES = "Yes";
   private static final String NO = "No";
 

   public Object getResult(ResultGetter getter) throws SQLException {
     String s = getter.getString();
     if (YES.equalsIgnoreCase(s)) {
       return new Boolean (true);
     } else if (NO.equalsIgnoreCase(s)) {
       return new Boolean (false);
     } else {
       throw new SQLException ("Unexpected value " + s + " found where "+YES+" or "+NO+" was expected.");
     }
   }
 

   public void setParameter(ParameterSetter setter, Object parameter) throws SQLException {
     boolean b = ((Boolean)parameter).booleanValue();
     if (b) {
       setter.setString(YES);
     } else {
       setter.setString(NO);
     }
   }
 

   public Object valueOf(String s) {
     if (YES.equalsIgnoreCase(s)) {
       return new Boolean (true);
     } else if (NO.equalsIgnoreCase(s)) {
       return new Boolean (false);
     } else {
       throw new SQLException ("Unexpected value " + s + " found where "+YES+" or "+NO+" was expected.");
     }
   }
 

 }