Class BeanProcessor

  • Direct Known Subclasses:
    GenerousBeanProcessor

    public class BeanProcessor
    extends Object

    BeanProcessor matches column names to bean property names and converts ResultSet columns into objects for those bean properties. Subclasses should override the methods in the processing chain to customize behavior.

    This class is thread-safe.

    Since:
    1.1
    See Also:
    BasicRowProcessor
    • Field Detail

      • PROPERTY_NOT_FOUND

        protected static final int PROPERTY_NOT_FOUND
        Special array value used by mapColumnsToProperties that indicates there is no bean property that matches a column from a ResultSet.
        See Also:
        Constant Field Values
    • Constructor Detail

      • BeanProcessor

        public BeanProcessor()
        Constructor for BeanProcessor.
      • BeanProcessor

        public BeanProcessor​(Map<String,​String> columnToPropertyOverrides)
        Constructor for BeanProcessor configured with column to property name overrides.
        Parameters:
        columnToPropertyOverrides - ResultSet column to bean property name overrides
        Since:
        1.5
    • Method Detail

      • getWriteMethod

        protected Method getWriteMethod​(Object target,
                                        PropertyDescriptor prop,
                                        Object value)
        Get the write method to use when setting value to the target.
        Parameters:
        target - Object where the write method will be called.
        prop - BeanUtils information.
        value - The value that will be passed to the write method.
        Returns:
        The Method to call on target to write value or null if there is no suitable write method.
      • mapColumnsToProperties

        protected int[] mapColumnsToProperties​(ResultSetMetaData rsmd,
                                               PropertyDescriptor[] props)
                                        throws SQLException
        The positions in the returned array represent column numbers. The values stored at each position represent the index in the PropertyDescriptor[] for the bean property that matches the column name. If no bean property was found for a column, the position is set to PROPERTY_NOT_FOUND.
        Parameters:
        rsmd - The ResultSetMetaData containing column information.
        props - The bean property descriptors.
        Returns:
        An int[] with column index to property index mappings. The 0th element is meaningless because JDBC column indexing starts at 1.
        Throws:
        SQLException - if a database access error occurs
      • newInstance

        protected <T> T newInstance​(Class<T> c)
                             throws SQLException
        Factory method that returns a new instance of the given Class. This is called at the start of the bean creation process and may be overridden to provide custom behavior like returning a cached bean instance.
        Type Parameters:
        T - The type of object to create
        Parameters:
        c - The Class to create an object from.
        Returns:
        A newly created object of the Class.
        Throws:
        SQLException - if creation failed.
      • populateBean

        public <T> T populateBean​(ResultSet resultSet,
                                  T bean)
                           throws SQLException
        Initializes the fields of the provided bean from the ResultSet.
        Type Parameters:
        T - The type of bean
        Parameters:
        resultSet - The result set.
        bean - The bean to be populated.
        Returns:
        An initialized object.
        Throws:
        SQLException - if a database error occurs.
      • processColumn

        protected Object processColumn​(ResultSet resultSet,
                                       int index,
                                       Class<?> propType)
                                throws SQLException
        Convert a ResultSet column into an object. Simple implementations could just call rs.getObject(index) while more complex implementations could perform type manipulation to match the column's type to the bean property type.

        This implementation calls the appropriate ResultSet getter method for the given property type to perform the type conversion. If the property type doesn't match one of the supported ResultSet types, getObject is called.

        Parameters:
        resultSet - The ResultSet currently being processed. It is positioned on a valid row before being passed into this method.
        index - The current column index being processed.
        propType - The bean property type that this column needs to be converted into.
        Returns:
        The object from the ResultSet at the given column index after optional type processing or null if the column value was SQL NULL.
        Throws:
        SQLException - if a database access error occurs
      • toBean

        public <T> T toBean​(ResultSet rs,
                            Class<? extends T> type)
                     throws SQLException
        Convert a ResultSet row into a JavaBean. This implementation uses reflection and BeanInfo classes to match column names to bean property names. Properties are matched to columns based on several factors: <br/> <ol> <li> The class has a writable property with the same name as a column. The name comparison is case insensitive. </li> <li> The column type can be converted to the property's set method parameter type with a ResultSet.get* method. If the conversion fails (ie. the property was an int and the column was a Timestamp) an SQLException is thrown. </li> </ol> <p> Primitive bean properties are set to their defaults when SQL NULL is returned from the ResultSet. Numeric fields are set to 0 and booleans are set to false. Object bean properties are set to null when SQL NULL is returned. This is the same behavior as the ResultSet get* methods. </p>
        Type Parameters:
        T - The type of bean to create
        Parameters:
        rs - ResultSet that supplies the bean data
        type - Class from which to create the bean instance
        Returns:
        the newly created bean
        Throws:
        SQLException - if a database access error occurs
      • toBeanList

        public <T> List<T> toBeanList​(ResultSet resultSet,
                                      Class<? extends T> type)
                               throws SQLException
        Convert a ResultSet into a List of JavaBeans. This implementation uses reflection and BeanInfo classes to match column names to bean property names. Properties are matched to columns based on several factors: <br/> <ol> <li> The class has a writable property with the same name as a column. The name comparison is case insensitive. </li> <li> The column type can be converted to the property's set method parameter type with a ResultSet.get* method. If the conversion fails (ie. the property was an int and the column was a Timestamp) an SQLException is thrown. </li> </ol>

        Primitive bean properties are set to their defaults when SQL NULL is returned from the ResultSet. Numeric fields are set to 0 and booleans are set to false. Object bean properties are set to null when SQL NULL is returned. This is the same behavior as the ResultSet get* methods. </p>

        Type Parameters:
        T - The type of bean to create
        Parameters:
        resultSet - ResultSet that supplies the bean data
        type - Class from which to create the bean instance
        Returns:
        the newly created List of beans
        Throws:
        SQLException - if a database access error occurs