public class ResultSetDynaClass extends Object implements DynaClass
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:
DynaBean
instance, you should
no longer use any previous instance.DynaBean
references.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); }
Modifier and Type | Field and Description |
---|---|
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<String,DynaProperty> |
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. |
Constructor and Description |
---|
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 . |
Modifier and Type | Method and Description |
---|---|
protected DynaProperty |
createDynaProperty(ResultSetMetaData metadata,
int i)
Factory method to create a new DynaProperty for the given index
into the result set metadata.
|
protected String |
getColumnName(String name)
Get the table column name for the specified property name.
|
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.Class DynaClass implementation class to support
different dynamic classes, with different sets of properties. |
protected Object |
getObject(ResultSet resultSet,
String name)
Get a column value from a
ResultSet for the specified name. |
Object |
getObjectFromResultSet(String name)
Get a value from the
ResultSet for the specified
property name. |
protected void |
introspect(ResultSet resultSet)
Introspect the metadata associated with our result set, and populate
the
properties and propertiesMap instance
variables. |
Iterator<DynaBean> |
iterator()
|
protected Class<?> |
loadClass(String className)
Loads the class of the given name which by default uses the class loader used
to load this library.
|
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.
|
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
getDynaProperties, getDynaProperty, getName, newInstance
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<String,DynaProperty> 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.
public ResultSetDynaClass(ResultSet resultSet) throws SQLException
Construct a new ResultSetDynaClass for the specified
ResultSet
. The property names corresponding
to column names in the result set will be lower cased.
resultSet
- The result set to be wrappedNullPointerException
- if resultSet
is null
SQLException
- if the metadata for this result set
cannot be introspectedpublic ResultSetDynaClass(ResultSet resultSet, boolean lowerCase) throws SQLException
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.
resultSet
- The result set to be wrappedlowerCase
- Should property names be lower cased?NullPointerException
- if resultSet
is null
SQLException
- if the metadata for this result set
cannot be introspectedpublic ResultSetDynaClass(ResultSet resultSet, boolean lowerCase, boolean useColumnLabel) throws SQLException
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.
resultSet
- The result set to be wrappedlowerCase
- Should property names be lower cased?useColumnLabel
- true if the column label should be used, otherwise falseNullPointerException
- if resultSet
is null
SQLException
- if the metadata for this result set
cannot be introspectedpublic Iterator<DynaBean> 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.
Iterator
of DynaBean
instancespublic Object getObjectFromResultSet(String name) throws SQLException
ResultSet
for the specified
property name.name
- The property nameSQLException
- if an error occursprotected Class<?> loadClass(String className) throws SQLException
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.
className
- The name of the class to loadSQLException
- if the class cannot be loadedpublic String getName()
Return the name of this DynaClass (analogous to the
getName()
method of java.lang.Class
DynaClass implementation class to support
different dynamic classes, with different sets of properties.
public DynaProperty getDynaProperty(String name)
Return a property descriptor for the specified property, if it
exists; otherwise, return null
.
getDynaProperty
in interface DynaClass
name
- Name of the dynamic property for which a descriptor
is requestedIllegalArgumentException
- if no property name is specifiedpublic 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.
getDynaProperties
in interface DynaClass
public DynaBean newInstance() throws IllegalAccessException, InstantiationException
Instantiate and return a new DynaBean instance, associated with this DynaClass. NOTE - This operation is not supported, and throws an exception.
newInstance
in interface DynaClass
DynaBean
instanceIllegalAccessException
- if the Class or the appropriate
constructor is not accessibleInstantiationException
- if this Class represents an abstract
class, an array class, a primitive type, or void; or if instantiation
fails for some other reasonpublic void setUseColumnLabel(boolean useColumnLabel)
useColumnLabel
- true if the column label should be used, otherwise falseprotected DynaProperty createDynaProperty(ResultSetMetaData metadata, int i) throws SQLException
Factory method to create a new DynaProperty for the given index into the result set metadata.
metadata
- is the result set metadatai
- is the column index in the metadataSQLException
- If an error occurs accessing the SQL metadataprotected void introspect(ResultSet resultSet) throws SQLException
Introspect the metadata associated with our result set, and populate
the properties
and propertiesMap
instance
variables.
resultSet
- The resultSet
whose metadata is to
be introspectedSQLException
- if an error is encountered processing the
result set metadataprotected Object getObject(ResultSet resultSet, String name) throws SQLException
ResultSet
for the specified name.resultSet
- The result setname
- The property nameSQLException
- if an error occursprotected String getColumnName(String name)
name
- The property nameCopyright © 2000–2019 The Apache Software Foundation. All rights reserved.