org.jpox.store.query
Class QueryUtils

java.lang.Object
  org.jpox.store.query.QueryUtils

public class QueryUtils
extends java.lang.Object

Utilities for use in queries.

Version:

$Revision: 1.14 $

Field Summary

protected static Localiser

LOCALISER Localiser for messages.

Constructor Summary

QueryUtils()

Method Summary

static java.lang.Object	createResultObjectUsingArgumentedConstructor(java.lang.Class resultClass, java.lang.Object[] fieldValues) Convenience method to create an instance of the result class with the provided field values, using a constructor taking the arguments.
static java.lang.Object	createResultObjectUsingDefaultConstructorAndSetters(java.lang.Class resultClass, java.lang.String[] resultFieldNames, java.util.Map resultClassFieldNames, java.lang.Object[] fieldValues) Convenience method to create an instance of the result class with the provided field values, using the default constructor and setting the fields using either public fields, or setters, or a put method.
static java.lang.String	getClassNameFromDiscriminatorResultSetRow(DatastoreClass table, java.sql.ResultSet rs, PersistenceManager pm) Convenience method that takes a result set that contains a discriminator column and returns the class name that it represents.
static java.lang.String	getClassNameFromJPOXMetaDataResultSetRow(java.sql.ResultSet rs) Convenience method that takes a result set that contains a JPOXMETADATA column and returns the class name.
static java.lang.String[]	getExpressionsFromString(java.lang.String str) Convenience method to split an expression string into its constituent parts where separated by commas.
static java.lang.reflect.Method	getPublicPutMethodForResultClass(java.lang.Class resultClass) Convenience method to return the put(Object, Object method for the result class.
static java.lang.reflect.Method	getPublicSetMethodForFieldOfResultClass(java.lang.Class resultClass, java.lang.String fieldName, java.lang.Class fieldType) Convenience method to return the setXXX method for a field of the result class.
static boolean	resultClassIsSimple(java.lang.String className) Utility to return if the passed result class is a simple type with a single value.
static boolean	resultClassIsUserType(java.lang.String className) Utility to return if the passed result class is a user-type, and so requires fields matching up.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

LOCALISER

protected static final Localiser LOCALISER

Localiser for messages.

Constructor Detail

QueryUtils

public QueryUtils()

Method Detail

resultClassIsUserType

public static boolean resultClassIsUserType(java.lang.String className)

Utility to return if the passed result class is a user-type, and so requires fields matching up.

Parameters:

className - the class name looked for

Returns:

Whether it is a user class

resultClassIsSimple

public static boolean resultClassIsSimple(java.lang.String className)

Utility to return if the passed result class is a simple type with a single value. Checks the class name against the supported "simple" JDOQL result-class types.

Parameters:

className - the class name looked for

Returns:

Whether the result class is "simple".

createResultObjectUsingArgumentedConstructor

public static java.lang.Object createResultObjectUsingArgumentedConstructor(java.lang.Class resultClass,
                                                                            java.lang.Object[] fieldValues)

Convenience method to create an instance of the result class with the provided field values, using a constructor taking the arguments. If the returned object is null there is no constructor with the correct signature.

Parameters:

resultClass - The class of results that need creating

fieldValues - The field values

Returns:

The result class object

createResultObjectUsingDefaultConstructorAndSetters

public static java.lang.Object createResultObjectUsingDefaultConstructorAndSetters(java.lang.Class resultClass,
                                                                                   java.lang.String[] resultFieldNames,
                                                                                   java.util.Map resultClassFieldNames,
                                                                                   java.lang.Object[] fieldValues)

Convenience method to create an instance of the result class with the provided field values, using the default constructor and setting the fields using either public fields, or setters, or a put method. If one of these parts is not found in the result class the returned object is null.

Parameters:

resultClass - Result class that we need to create an object of

resultFieldNames - Names of the fields in the results

resultClassFieldNames - Map of the result class fields, keyed by the field name

fieldValues - The field values

Returns:

The result class object

getPublicSetMethodForFieldOfResultClass

public static java.lang.reflect.Method getPublicSetMethodForFieldOfResultClass(java.lang.Class resultClass,
                                                                               java.lang.String fieldName,
                                                                               java.lang.Class fieldType)

Convenience method to return the setXXX method for a field of the result class.

Parameters:

resultClass - The result class

fieldName - Name of the field

fieldType - The type of the field being set

Returns:

The setter method

getPublicPutMethodForResultClass

public static java.lang.reflect.Method getPublicPutMethodForResultClass(java.lang.Class resultClass)

Convenience method to return the put(Object, Object method for the result class.

Parameters:

resultClass - The result class

Returns:

The put(Object, Object) method

getExpressionsFromString

public static java.lang.String[] getExpressionsFromString(java.lang.String str)

Convenience method to split an expression string into its constituent parts where separated by commas. This is used in the case of, for example, a result specification, to get the column definitions.

Parameters:

str - The expression string

Returns:

The expression parts

getClassNameFromDiscriminatorResultSetRow

public static java.lang.String getClassNameFromDiscriminatorResultSetRow(DatastoreClass table,
                                                                         java.sql.ResultSet rs,
                                                                         PersistenceManager pm)

Convenience method that takes a result set that contains a discriminator column and returns the class name that it represents. TODO This is RDBMS specific so consider moving it to an RDBMSQueryUtils in the future.

Parameters:

table - Primary table of the select (so we can identify the primary class and discriminator range)

rs - The result set

pm - Persistence Manager

Returns:

The class name for the object represented in the current row

getClassNameFromJPOXMetaDataResultSetRow

public static java.lang.String getClassNameFromJPOXMetaDataResultSetRow(java.sql.ResultSet rs)

Convenience method that takes a result set that contains a JPOXMETADATA column and returns the class name. TODO This is RDBMS specific so consider moving it to an RDBMSQueryUtils in the future.

Parameters:

rs - The result set

Returns:

The class name for the object represented in the current row