Java Programming with Oracle JDBC

Accessor Methods

As I alluded to earlier in the section on cursor positioning, the ResultSet object has a set of methods that allow you to get access to the column values for a row in a result set. These ResultSet accessor methods are affectionately called the getXXX( ) methods. The XXX is a placeholder for one of the Java data types from Table 10-1. Well, almost. When the XXX is replaced with a class name such as Double, which is a wrapper class for the primitive double, the getXXX( ) method returns the primitive data type, not an instance of the class. For example, getString( ) returns a String object, whereas getDouble( ) (Double is the name of a wrapper class for the primitive data type double) returns a double primitive type, not an instance of the wrapper class Double. The getXXX( ) methods have two signatures:

dataType getdataType (int columnIndex)

dataType getdataType (String columnName)

which breaks down as:

dataType

One of the Java data types from Table 10-1. For primitive data types that have wrapper classes, the class name is appended to get. For example, the primitive double data type has a wrapper class named Double, so the get method is named getDouble( ), but the primitive data type’s value is passed as the second parameter, not as an instance of its wrapper class.

columnIndex

The position of the column in the select list, from left to right, starting with 1.

columnName

The name or alias for the column in the select list. This value is not case-sensitive.

Using the ...