Package org.apache.commons.dbutils.handlers

Class BeanMapHandler<K,​V>

  • Type Parameters:
    K - the type of keys maintained by the returned map
    V - the type of the bean
    All Implemented Interfaces:
    ResultSetHandler<Map<K,​V>>
    public class BeanMapHandler<K,​V>
extends AbstractKeyedHandler<K,​V>

    ResultSetHandler implementation that returns a Map of Beans. ResultSet rows are converted into Beans which are then stored in a Map under the given key.

    If you had a Person table with a primary key column called ID, you could retrieve rows from the table like this: 

     ResultSetHandler<Map<Long, Person>> h = new BeanMapHandler<Long, Person>(Person.class, "id");
 Map<Long, Person> found = queryRunner.query("select id, name, age from person", h);
 Person jane = found.get(1L); // jane's id is 1
 String janesName = jane.getName();
 Integer janesAge = jane.getAge();
    Note that the "id" passed to BeanMapHandler can be in any case. The data type returned for id is dependent upon how your JDBC driver converts SQL column types from the Person table into Java types. The "name" and "age" columns are converted according to their property descriptors by DbUtils. </p>

    This class is thread safe. </p>

    Since:
    1.5
    See Also:
    ResultSetHandler

    • Constructor Detail

      • BeanMapHandler

        public BeanMapHandler​(Class<V> type)
        Creates a new instance of BeanMapHandler. The value of the first column of each row will be a key in the Map.
        Parameters:
        type - The Class that objects returned from createRow() are created from.

      • BeanMapHandler

        public BeanMapHandler​(Class<V> type,
                      int columnIndex)
        Creates a new instance of BeanMapHandler.
        Parameters:
        type - The Class that objects returned from createRow() are created from.
        columnIndex - The values to use as keys in the Map are retrieved from the column at this index.

      • BeanMapHandler

        public BeanMapHandler​(Class<V> type,
                      RowProcessor convert)
        Creates a new instance of BeanMapHandler. The value of the first column of each row will be a key in the Map.
        Parameters:
        type - The Class that objects returned from createRow() are created from.
        convert - The RowProcessor implementation to use when converting rows into Beans

      • BeanMapHandler

        public BeanMapHandler​(Class<V> type,
                      String columnName)
        Creates a new instance of BeanMapHandler.
        Parameters:
        type - The Class that objects returned from createRow() are created from.
        columnName - The values to use as keys in the Map are retrieved from the column with this name.