Package org.apache.commons.dbutils.handlers

Class ScalarHandler<T>

  • Type Parameters:
    T - The type of the scalar
    All Implemented Interfaces:
    ResultSetHandler<T>
    public class ScalarHandler<T>
extends java.lang.Object
implements ResultSetHandler<T>
    ResultSetHandler implementation that converts one ResultSet column into an Object. This class is thread safe.
    See Also:
    ResultSetHandler

    • Field Summary

      Fields 
      Modifier and Type Field Description
      private int columnIndex
      The column number to retrieve.
      private java.lang.String columnName
      The column name to retrieve.

    • Constructor Summary

      Constructors 
      Modifier Constructor Description
        ScalarHandler()
      Creates a new instance of ScalarHandler.
        ScalarHandler​(int columnIndex)
      Creates a new instance of ScalarHandler.
      private ScalarHandler​(int columnIndex, java.lang.String columnName)
      Helper constructor
        ScalarHandler​(java.lang.String columnName)
      Creates a new instance of ScalarHandler.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      T handle​(java.sql.ResultSet rs)
      Returns one ResultSet column as an object via the ResultSet.getObject() method that performs type conversions.

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Field Detail

      • columnIndex

        private final int columnIndex
        The column number to retrieve.

      • columnName

        private final java.lang.String columnName
        The column name to retrieve. Either columnName or columnIndex will be used but never both.

    • Constructor Detail

      • ScalarHandler

        public ScalarHandler()
        Creates a new instance of ScalarHandler. The first column will be returned from handle().

      • ScalarHandler

        public ScalarHandler​(int columnIndex)
        Creates a new instance of ScalarHandler.
        Parameters:
        columnIndex - The index of the column to retrieve from the ResultSet.

      • ScalarHandler

        public ScalarHandler​(java.lang.String columnName)
        Creates a new instance of ScalarHandler.
        Parameters:
        columnName - The name of the column to retrieve from the ResultSet.

      • ScalarHandler

        private ScalarHandler​(int columnIndex,
                      java.lang.String columnName)
        Helper constructor
        Parameters:
        columnIndex - The index of the column to retrieve from the ResultSet.
        columnName - The name of the column to retrieve from the ResultSet.

    • Method Detail

      • handle

        public T handle​(java.sql.ResultSet rs)
         throws java.sql.SQLException
        Returns one ResultSet column as an object via the ResultSet.getObject() method that performs type conversions.
        Specified by:
        handle in interface ResultSetHandler<T>
        Parameters:
        rs - ResultSet to process.
        Returns:
        The column or null if there are no rows in the ResultSet.
        Throws:
        java.sql.SQLException - if a database access error occurs
        java.lang.ClassCastException - if the class datatype does not match the column type
        See Also:
        ResultSetHandler.handle(java.sql.ResultSet)