public class

ResultSetDynaClass

extends Object
implements Serializable DynaClass
java.lang.Object
   ↳ org.apache.commons.beanutils.ResultSetDynaClass

Class Overview

Implementation of DynaClass for DynaBeans that wrap the java.sql.Row objects of a java.sql.ResultSet. The normal usage pattern is something like:

   ResultSet rs = ...;
   ResultSetDynaClass rsdc = new ResultSetDynaClass(rs);
   Iterator rows = rsdc.iterator();
   while (rows.hasNext())  {
     DynaBean row = (DynaBean) rows.next();
     ... process this row ...
   }
   rs.close();

Each column in the result set will be represented as a DynaBean property of the corresponding name (optionally forced to lower case for portability).

WARNING - Any DynaBean instance returned by this class, or from the Iterator returned by the iterator() method, is directly linked to the row that the underlying result set is currently positioned at. This has the following implications:

  • Once you retrieve a different DynaBean instance, you should no longer use any previous instance.
  • Changing the position of the underlying result set will change the data that the DynaBean references.
  • Once the underlying result set is closed, the DynaBean instance may no longer be used.

Any database data that you wish to utilize outside the context of the current row of an open result set must be copied. For example, you could use the following code to create standalone copies of the information in a result set:

   ArrayList results = new ArrayList(); // To hold copied list
   ResultSetDynaClass rsdc = ...;
   DynaProperty[] properties = rsdc.getDynaProperties();
   BasicDynaClass bdc =
     new BasicDynaClass("foo", BasicDynaBean.class,
                        rsdc.getDynaProperties());
   Iterator rows = rsdc.iterator();
   while (rows.hasNext()) {
     DynaBean oldRow = (DynaBean) rows.next();
     DynaBean newRow = bdc.newInstance();
     PropertyUtils.copyProperties(newRow, oldRow);
     results.add(newRow);
   }

Summary

Fields
protected boolean lowerCase

Flag defining whether column names should be lower cased when converted to property names.
protected DynaProperty[] properties

The set of dynamic properties that are part of this DynaClass.
protected Map propertiesMap

The set of dynamic properties that are part of this DynaClass, keyed by the property name.
protected ResultSet resultSet

The ResultSet we are wrapping.
Public Constructors
ResultSetDynaClass(ResultSet resultSet)

Construct a new ResultSetDynaClass for the specified ResultSet.

ResultSetDynaClass(ResultSet resultSet, boolean lowerCase)

Construct a new ResultSetDynaClass for the specified ResultSet.

ResultSetDynaClass(ResultSet resultSet, boolean lowerCase, boolean useColumnLabel)

Construct a new ResultSetDynaClass for the specified ResultSet.

Public Methods
DynaProperty[] getDynaProperties()

Return an array of ProperyDescriptors for the properties currently defined in this DynaClass.

DynaProperty getDynaProperty(String name)

Return a property descriptor for the specified property, if it exists; otherwise, return null.

String getName()

Return the name of this DynaClass (analogous to the getName() method of java.lang.ClassDynaClass implementation class to support different dynamic classes, with different sets of properties.

Object getObjectFromResultSet(String name)
Get a value from the ResultSet for the specified property name.
Iterator iterator()

Return an Iterator of DynaBean instances for each row of the wrapped ResultSet, in "forward" order.

DynaBean newInstance()

Instantiate and return a new DynaBean instance, associated with this DynaClass.

void setUseColumnLabel(boolean useColumnLabel)
Set whether the column label or name should be used for the property name.
Protected Methods
DynaProperty createDynaProperty(ResultSetMetaData metadata, int i)

Factory method to create a new DynaProperty for the given index into the result set metadata.

String getColumnName(String name)
Get the table column name for the specified property name.
Object getObject(ResultSet resultSet, String name)
Get a column value from a ResultSet for the specified name.
void introspect(ResultSet resultSet)

Introspect the metadata associated with our result set, and populate the properties and propertiesMap instance variables.

Class loadClass(String className)

Loads the class of the given name which by default uses the class loader used to load this library.

[Expand]
Inherited Methods
From class java.lang.Object
From interface org.apache.commons.beanutils.DynaClass

Fields

protected boolean lowerCase

Flag defining whether column names should be lower cased when converted to property names.

protected DynaProperty[] properties

The set of dynamic properties that are part of this DynaClass.

protected Map propertiesMap

The set of dynamic properties that are part of this DynaClass, keyed by the property name. Individual descriptor instances will be the same instances as those in the properties list.

protected ResultSet resultSet

The ResultSet we are wrapping.

Public Constructors

public ResultSetDynaClass (ResultSet resultSet)

Construct a new ResultSetDynaClass for the specified ResultSet. The property names corresponding to column names in the result set will be lower cased.

Parameters
resultSet The result set to be wrapped
Throws
NullPointerException if resultSet is null
SQLException if the metadata for this result set cannot be introspected

public ResultSetDynaClass (ResultSet resultSet, boolean lowerCase)

Construct a new ResultSetDynaClass for the specified ResultSet. The property names corresponding to the column names in the result set will be lower cased or not, depending on the specified lowerCase value.

WARNING - If you specify false for lowerCase, the returned property names will exactly match the column names returned by your JDBC driver. Because different drivers might return column names in different cases, the property names seen by your application will vary depending on which JDBC driver you are using.

Parameters
resultSet The result set to be wrapped
lowerCase Should property names be lower cased?
Throws
NullPointerException if resultSet is null
SQLException if the metadata for this result set cannot be introspected

public ResultSetDynaClass (ResultSet resultSet, boolean lowerCase, boolean useColumnLabel)

Construct a new ResultSetDynaClass for the specified ResultSet. The property names corresponding to the column names in the result set will be lower cased or not, depending on the specified lowerCase value.

WARNING - If you specify false for lowerCase, the returned property names will exactly match the column names returned by your JDBC driver. Because different drivers might return column names in different cases, the property names seen by your application will vary depending on which JDBC driver you are using.

Parameters
resultSet The result set to be wrapped
lowerCase Should property names be lower cased?
useColumnLabel true if the column label should be used, otherwise false
Throws
NullPointerException if resultSet is null
SQLException if the metadata for this result set cannot be introspected

Public Methods

public DynaProperty[] getDynaProperties ()

Return an array of ProperyDescriptors for the properties currently defined in this DynaClass. If no properties are defined, a zero-length array will be returned.

Returns
  • the set of properties for this DynaClass

public DynaProperty getDynaProperty (String name)

Return a property descriptor for the specified property, if it exists; otherwise, return null.

Parameters
name Name of the dynamic property for which a descriptor is requested
Returns
  • The descriptor for the specified property
Throws
IllegalArgumentException if no property name is specified

public String getName ()

Return the name of this DynaClass (analogous to the getName() method of java.lang.ClassDynaClass implementation class to support different dynamic classes, with different sets of properties.

Returns
  • the name of the DynaClass

public Object getObjectFromResultSet (String name)

Get a value from the ResultSet for the specified property name.

Parameters
name The property name
Returns
  • The value
Throws
SQLException if an error occurs

public Iterator iterator ()

Return an Iterator of DynaBean instances for each row of the wrapped ResultSet, in "forward" order. Unless the underlying result set supports scrolling, this method should be called only once.

Returns

public DynaBean newInstance ()

Instantiate and return a new DynaBean instance, associated with this DynaClass. NOTE - This operation is not supported, and throws an exception.

Returns
  • A new DynaBean instance
Throws
IllegalAccessException if the Class or the appropriate constructor is not accessible
InstantiationException if this Class represents an abstract class, an array class, a primitive type, or void; or if instantiation fails for some other reason

public void setUseColumnLabel (boolean useColumnLabel)

Set whether the column label or name should be used for the property name.

Parameters
useColumnLabel true if the column label should be used, otherwise false

Protected Methods

protected DynaProperty createDynaProperty (ResultSetMetaData metadata, int i)

Factory method to create a new DynaProperty for the given index into the result set metadata.

Parameters
metadata is the result set metadata
i is the column index in the metadata
Returns
  • the newly created DynaProperty instance
Throws
SQLException If an error occurs accessing the SQL metadata

protected String getColumnName (String name)

Get the table column name for the specified property name.

Parameters
name The property name
Returns
  • The column name (which can be different if the lowerCase option is used).

protected Object getObject (ResultSet resultSet, String name)

Get a column value from a ResultSet for the specified name.

Parameters
resultSet The result set
name The property name
Returns
  • The value
Throws
SQLException if an error occurs

protected void introspect (ResultSet resultSet)

Introspect the metadata associated with our result set, and populate the properties and propertiesMap instance variables.

Parameters
resultSet The resultSet whose metadata is to be introspected
Throws
SQLException if an error is encountered processing the result set metadata

protected Class loadClass (String className)

Loads the class of the given name which by default uses the class loader used to load this library. Dervations of this class could implement alternative class loading policies such as using custom ClassLoader or using the Threads's context class loader etc.

Parameters
className The name of the class to load
Returns
  • The loaded class
Throws
SQLException if the class cannot be loaded