Class ResultSetDynaClass
- All Implemented Interfaces:
DynaClass
Implements DynaClass for DynaBeans that wrap the java.sql.Row</code> objects of a <code>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
DynaBeaninstance, you should no longer use any previous instance. - Changing the position of the underlying result set will change the data that the
DynaBeanreferences. - Once the underlying result set is closed, the
DynaBeaninstance 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:
List 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);
}
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Field Summary
FieldsModifier and TypeFieldDescriptionprotected booleanFlag defining whether column names should be lower cased when converted to property names.protected DynaProperty[]The set of dynamic properties that are part of thisDynaClass.protected Map<String, DynaProperty> The set of dynamic properties that are part of thisDynaClass, keyed by the property name.protected ResultSetTheResultSetwe are wrapping. -
Constructor Summary
ConstructorsConstructorDescriptionResultSetDynaClass(ResultSet resultSet) Constructs a new ResultSetDynaClass for the specifiedResultSet.ResultSetDynaClass(ResultSet resultSet, boolean lowerCase) Constructs a new ResultSetDynaClass for the specifiedResultSet.ResultSetDynaClass(ResultSet resultSet, boolean lowerCase, boolean useColumnLabel) Constructs a new ResultSetDynaClass for the specifiedResultSet. -
Method Summary
Modifier and TypeMethodDescriptionprotected DynaPropertycreateDynaProperty(ResultSetMetaData metadata, int i) Factory method to create a new DynaProperty for the given index into the result set metadata.protected StringgetColumnName(String name) Gets the table column name for the specified property name.Gets an array ofPropertyDescriptorfor the properties currently defined in this DynaClass.getDynaProperty(String name) Gets a property descriptor for the specified property, if it exists; otherwise, returnnull.getName()Gets the name of this DynaClass (analogous to thegetName()</code> method of <code>java.lang.Class, which allows the sameDynaClassimplementation class to support different dynamic classes, with different sets of properties.protected ObjectGets a column value from aResultSetfor the specified name.getObjectFromResultSet(String name) Gets a value from theResultSetfor the specified property name.protected voidintrospect(ResultSet resultSet) Introspect the metadata associated with our result set, and populate theproperties</code> and <code>propertiesMapinstance variables.iterator()protected Class<?> Loads the class of the given name which by default uses the class loader used to load this library.Instantiate and return a new DynaBean instance, associated with this DynaClass.voidsetUseColumnLabel(boolean useColumnLabel) Sets whether the column label or name should be used for the property name.
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Field Details
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resultSet
The
ResultSetwe are wrapping. -
lowerCase
protected boolean lowerCaseFlag defining whether column names should be lower cased when converted to property names.
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properties
The set of dynamic properties that are part of this
DynaClass. -
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 thepropertieslist.
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Constructor Details
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ResultSetDynaClass
Constructs 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- ifresultSetisnullSQLException- if the metadata for this result set cannot be introspected
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ResultSetDynaClass
Constructs 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 specifiedlowerCasevalue.WARNING - If you specify
falseforlowerCase, 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 wrappedlowerCase- Should property names be lower cased?- Throws:
NullPointerException- ifresultSetisnullSQLException- if the metadata for this result set cannot be introspected
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ResultSetDynaClass
public ResultSetDynaClass(ResultSet resultSet, boolean lowerCase, boolean useColumnLabel) throws SQLException Constructs 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 specifiedlowerCasevalue.WARNING - If you specify
falseforlowerCase, 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 wrappedlowerCase- Should property names be lower cased?useColumnLabel- true if the column label should be used, otherwise false- Throws:
NullPointerException- ifresultSetisnullSQLException- if the metadata for this result set cannot be introspected- Since:
- 1.8.3
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Method Details
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getObjectFromResultSet
Gets a value from theResultSetfor the specified property name.- Parameters:
name- The property name- Returns:
- The value
- Throws:
SQLException- if an error occurs- Since:
- 1.8.0
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iterator
Return an
IteratorofDynaBeaninstances for each row of the wrappedResultSet, in "forward" order. Unless the underlying result set supports scrolling, this method should be called only once.- Returns:
- An
IteratorofDynaBeaninstances
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loadClass
Loads the class of the given name which by default uses the class loader used to load this library. Derivations 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
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createDynaProperty
Factory method to create a new DynaProperty for the given index into the result set metadata.
- Parameters:
metadata- is the result set metadatai- is the column index in the metadata- Returns:
- the newly created DynaProperty instance
- Throws:
SQLException- If an error occurs accessing the SQL metadata
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getColumnName
Gets 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).
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getDynaProperties
Gets an array of
PropertyDescriptorfor the properties currently defined in this DynaClass. If no properties are defined, a zero-length array will be returned.- Specified by:
getDynaPropertiesin interfaceDynaClass- Returns:
- the set of properties for this DynaClass
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getDynaProperty
Gets a property descriptor for the specified property, if it exists; otherwise, return
null.- Specified by:
getDynaPropertyin interfaceDynaClass- 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
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getName
Gets the name of this DynaClass (analogous to the
getName()</code> method of <code>java.lang.Class, which allows the sameDynaClassimplementation class to support different dynamic classes, with different sets of properties. -
getObject
Gets a column value from aResultSetfor the specified name.- Parameters:
resultSet- The result setname- The property name- Returns:
- The value
- Throws:
SQLException- if an error occurs
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introspect
Introspect the metadata associated with our result set, and populate the
properties</code> and <code>propertiesMapinstance variables.- Parameters:
resultSet- TheresultSetwhose metadata is to be introspected- Throws:
SQLException- if an error is encountered processing the result set metadata
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newInstance
Instantiate and return a new DynaBean instance, associated with this DynaClass. NOTE - This operation is not supported, and throws an exception.
- Specified by:
newInstancein interfaceDynaClass- Returns:
- A new
DynaBeaninstance - Throws:
IllegalAccessException- 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 reason
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setUseColumnLabel
public void setUseColumnLabel(boolean useColumnLabel) Sets 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
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