org.springframework.jdbc.core
Class BeanPropertyRowMapper<T>

java.lang.Object
  extended by org.springframework.jdbc.core.BeanPropertyRowMapper<T>
All Implemented Interfaces:
RowMapper<T>
Direct Known Subclasses:
ParameterizedBeanPropertyRowMapper

public class BeanPropertyRowMapper<T>
extends Object
implements RowMapper<T>

RowMapper implementation that converts a row into a new instance of the specified mapped target class. The mapped target class must be a top-level class and it must have a default or no-arg constructor.

Column values are mapped based on matching the column name as obtained from result set metadata to public setters for the corresponding properties. The names are matched either directly or by transforming a name separating the parts with underscores to the same name using "camel" case.

Mapping is provided for fields in the target class for many common types, e.g.: String, boolean, Boolean, byte, Byte, short, Short, int, Integer, long, Long, float, Float, double, Double, BigDecimal, java.util.Date, etc.

To facilitate mapping between columns and fields that don't have matching names, try using column aliases in the SQL statement like "select fname as first_name from customer".

For 'null' values read from the databasem, we will attempt to call the setter, but in the case of Java primitives, this causes a TypeMismatchException. This class can be configured (using the primitivesDefaultedForNullValue property) to trap this exception and use the primitives default value. Be aware that if you use the values from the generated bean to update the database the primitive value will have been set to the primitive's default value instead of null.

Please note that this class is designed to provide convenience rather than high performance. For best performance consider using a custom RowMapper.

Since:
2.5
Author:
Thomas Risberg, Juergen Hoeller

Field Summary
protected  Log logger
          Logger available to subclasses
 
Constructor Summary
BeanPropertyRowMapper()
          Create a new BeanPropertyRowMapper for bean-style configuration.
BeanPropertyRowMapper(Class<T> mappedClass)
          Create a new BeanPropertyRowMapper, accepting unpopulated properties in the target bean.
BeanPropertyRowMapper(Class<T> mappedClass, boolean checkFullyPopulated)
          Create a new BeanPropertyRowMapper.
 
Method Summary
protected  Object getColumnValue(ResultSet rs, int index, PropertyDescriptor pd)
          Retrieve a JDBC object value for the specified column.
 Class<T> getMappedClass()
          Get the class that we are mapping to.
protected  void initBeanWrapper(BeanWrapper bw)
          Initialize the given BeanWrapper to be used for row mapping.
protected  void initialize(Class<T> mappedClass)
          Initialize the mapping metadata for the given class.
 boolean isCheckFullyPopulated()
          Return whether we're strictly validating that all bean properties have been mapped from corresponding database fields.
 boolean isPrimitivesDefaultedForNullValue()
          Set whether we're defaulting Java primitives in the case of mapping a null value from corresponding database fields.
 T mapRow(ResultSet rs, int rowNumber)
          Extract the values for all columns in the current row.
 void setCheckFullyPopulated(boolean checkFullyPopulated)
          Set whether we're strictly validating that all bean properties have been mapped from corresponding database fields.
 void setMappedClass(Class<T> mappedClass)
          Set the class that each row should be mapped to.
 void setPrimitivesDefaultedForNullValue(boolean primitivesDefaultedForNullValue)
          Return whether we're defaulting Java primitives in the case of mapping a null value from corresponding database fields.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

logger

protected final Log logger
Logger available to subclasses

Constructor Detail

BeanPropertyRowMapper

public BeanPropertyRowMapper()
Create a new BeanPropertyRowMapper for bean-style configuration.

See Also:
setMappedClass(java.lang.Class), setCheckFullyPopulated(boolean)

BeanPropertyRowMapper

public BeanPropertyRowMapper(Class<T> mappedClass)
Create a new BeanPropertyRowMapper, accepting unpopulated properties in the target bean.

Parameters:
mappedClass - the class that each row should be mapped to

BeanPropertyRowMapper

public BeanPropertyRowMapper(Class<T> mappedClass,
                             boolean checkFullyPopulated)
Create a new BeanPropertyRowMapper.

Parameters:
mappedClass - the class that each row should be mapped to
checkFullyPopulated - whether we're strictly validating that all bean properties have been mapped from corresponding database fields
Method Detail

setMappedClass

public void setMappedClass(Class<T> mappedClass)
Set the class that each row should be mapped to.


initialize

protected void initialize(Class<T> mappedClass)
Initialize the mapping metadata for the given class.

Parameters:
mappedClass - the mapped class.

getMappedClass

public final Class<T> getMappedClass()
Get the class that we are mapping to.


setCheckFullyPopulated

public void setCheckFullyPopulated(boolean checkFullyPopulated)
Set whether we're strictly validating that all bean properties have been mapped from corresponding database fields.

Default is false, accepting unpopulated properties in the target bean.


isCheckFullyPopulated

public boolean isCheckFullyPopulated()
Return whether we're strictly validating that all bean properties have been mapped from corresponding database fields.


isPrimitivesDefaultedForNullValue

public boolean isPrimitivesDefaultedForNullValue()
Set whether we're defaulting Java primitives in the case of mapping a null value from corresponding database fields.

Default is false, throwing an exception when nulls are mapped to Java primitives.


setPrimitivesDefaultedForNullValue

public void setPrimitivesDefaultedForNullValue(boolean primitivesDefaultedForNullValue)
Return whether we're defaulting Java primitives in the case of mapping a null value from corresponding database fields.


mapRow

public T mapRow(ResultSet rs,
                int rowNumber)
         throws SQLException
Extract the values for all columns in the current row.

Utilizes public setters and result set metadata.

Specified by:
mapRow in interface RowMapper<T>
Parameters:
rs - the ResultSet to map (pre-initialized for the current row)
rowNumber - the number of the current row
Returns:
the result object for the current row
Throws:
SQLException - if a SQLException is encountered getting column values (that is, there's no need to catch SQLException)
See Also:
ResultSetMetaData

initBeanWrapper

protected void initBeanWrapper(BeanWrapper bw)
Initialize the given BeanWrapper to be used for row mapping. To be called for each row.

The default implementation is empty. Can be overridden in subclasses.

Parameters:
bw - the BeanWrapper to initialize

getColumnValue

protected Object getColumnValue(ResultSet rs,
                                int index,
                                PropertyDescriptor pd)
                         throws SQLException
Retrieve a JDBC object value for the specified column.

The default implementation calls JdbcUtils.getResultSetValue(java.sql.ResultSet, int, Class). Subclasses may override this to check specific value types upfront, or to post-process values return from getResultSetValue.

Parameters:
rs - is the ResultSet holding the data
index - is the column index
pd - the bean property that each result object is expected to match (or null if none specified)
Returns:
the Object value
Throws:
SQLException - in case of extraction failure
See Also:
JdbcUtils.getResultSetValue(java.sql.ResultSet, int, Class)