org.datanucleus.query
Class QueryUtils

java.lang.Object
  org.datanucleus.query.QueryUtils

public class QueryUtils
extends java.lang.Object

Utilities for use in queries.

Field Summary

protected static java.lang.Class[]	classArrayObjectObject Convenience Class[] for parameter types in getMethod call.
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.lang.reflect.Field[] resultFields, 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.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[]	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 java.lang.String	getStringValue(java.lang.Object obj) Convenience method to get the String value for an Object.
static java.lang.String	getStringValueForExpression(Expression expr, SymbolTable symbolTable) Convenience method to get the String value for an Expression.
static java.lang.Object	getValueForParameterExpression(java.util.Map parameterValues, ParameterExpression paramExpr) Convenience method to get the value for a ParameterExpression.
static java.lang.Object	getValueForParameterExpression(SymbolTable symtbl, ParameterExpression paramExpr) Convenience method to get the value for a ParameterExpression.
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.

classArrayObjectObject

protected static java.lang.Class[] classArrayObjectObject

Convenience Class[] for parameter types in getMethod call.

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

createResultObjectUsingDefaultConstructorAndSetters

public static java.lang.Object createResultObjectUsingDefaultConstructorAndSetters(java.lang.Class resultClass,
                                                                                   java.lang.String[] resultFieldNames,
                                                                                   java.lang.reflect.Field[] resultFields,
                                                                                   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

resultFields - (java.lang.reflect.)Field objects for the fields in the results

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

getValueForParameterExpression

public static java.lang.Object getValueForParameterExpression(SymbolTable symtbl,
                                                              ParameterExpression paramExpr)

Convenience method to get the value for a ParameterExpression.

Parameters:

symtbl - Symbol table containing the parameter symbol

paramExpr - Expression

Returns:

The value in the object for this expression

getValueForParameterExpression

public static java.lang.Object getValueForParameterExpression(java.util.Map parameterValues,
                                                              ParameterExpression paramExpr)

Convenience method to get the value for a ParameterExpression.

Parameters:

parameterValues - Input parameter values keyed by the parameter name/position

paramExpr - Expression

Returns:

The value in the object for this expression

getStringValue

public static java.lang.String getStringValue(java.lang.Object obj)

Convenience method to get the String value for an Object. Currently String, Character and Number are supported.

Parameters:

obj - Object

Returns:

The String value for the Object

getStringValueForExpression

public static java.lang.String getStringValueForExpression(Expression expr,
                                                           SymbolTable symbolTable)

Convenience method to get the String value for an Expression. Currently only ParameterExpression and Literal are supported.

Parameters:

primExpr - Expression

Returns:

The String value in the object for this expression