org.datanucleus.util

Class ClassUtils

java.lang.Object

org.datanucleus.util.ClassUtils

public class ClassUtils
extends Object

Utilities for handling classes. These are to supplement the methods provided by the Class object.

Field Summary

Fields

Modifier and Type	Field and Description
protected static Map	constructorsCache caching for constructors - using caching, the perf is at least doubled
protected static Localiser	LOCALISER Localisation utility for output messages

Constructor Summary

Constructors

Constructor and Description
ClassUtils()

Method Summary

Methods

Modifier and Type	Method and Description
static void	assertClassForJarExistsInClasspath(ClassLoaderResolver clr, String className, String jarName) Convenience method to throw a NucleusUserException if the specified class is not loadable from the ClassLoaderResolver.
static boolean	classesAreDescendents(ClassLoaderResolver clr, String class_name_1, String class_name_2) Method to check if 2 classes are direct descendents.
static void	clearFlags(boolean[] flags) Utility to clear the supplied flags.
static void	clearFlags(boolean[] flags, int[] fields) Utility to clear the supplied flags.
static Object	convertValue(Object value, Class cls) Convenience method to convert the passed value to an object of the specified type (if possible).
static String	createFullClassName(String pkg_name, String cls_name) Utility to create the full class name given the package and class name.
static void	dumpClassInformation(Class cls) Utility to use Reflection to dump out the details of a class.
static boolean	getBitFromInt(int bits, int bitIndex) Convenience method to get the value of a bit from an int when we are storing (up to 32) boolean in an int for memory utilisation purposes.
static Collection<File>	getClassFilesForDirectory(File dir, boolean normal_classes, boolean inner_classes) Method to return the class files below the specified directory.
static Class	getClassForGenericType(Type genericType, int pos) Convenience method to attempt to return the class for the provided generic type.
static Class	getClassForMemberOfClass(Class cls, String memberName) Method that returns the class type of a member of the specified class (if present).
static String	getClassNameForClass(Class cls) Utility to return the class name without the package name for a class.
static String	getClassNameForFileName(String fileName, ClassLoaderResolver clr) Convenience method to try to find the class name stored in the specified file.
static String	getClassnameForFilename(String filename, String rootfilename) Utility to get the Class name given the file name and the file name of the root of the package structure.
static String	getClassNameForFileURL(URL fileURL) Utility to find the class name of a class given the absolute file name of its class file.
static String[]	getClassNamesForDirectoryAndBelow(File dir) Convenience method to return the names of classes specified in the directory and below.
static String[]	getClassNamesForJarFile(String jarFileName) Convenience accessor for the names of all class files in the jar file with the specified name.
static String[]	getClassNamesForJarFile(URI jarFileURI) Convenience accessor for the names of all class files in the jar file with the specified URL.
static String[]	getClassNamesForJarFile(URL jarFileURL) Convenience accessor for the names of all class files in the jar file with the specified URL.
static Class	getCollectionElementType(Class type, Type genericType) Convenience method to extract the element type of a collection when using JDK1.5 generics given the input field.
static String	getCollectionElementType(Field field) Convenience method to extract the element type of a collection when using JDK1.5 generics given the input field.
static String	getCollectionElementType(Method method) Convenience method to extract the element type of a collection when using JDK1.5 generics, given the input method (getter).
static Constructor	getConstructorWithArguments(Class cls, Class[] argTypes) Convenience method to return the constructor of the passed class that accepts the supplied argument types.
static Field	getFieldForClass(Class cls, String fieldName) Obtain a field from a class or superclasses using reflection.
static String	getFieldNameForJavaBeanGetter(String methodName) Generate a field name for JavaBeans compatible getter method
static String	getFieldNameForJavaBeanSetter(String methodName) Generate a field name for JavaBeans compatible setter method
static Collection<File>	getFilesForDirectory(File dir) Method to return the files below the specified directory.
static int[]	getFlagsSetTo(boolean[] flags, boolean state) Returns an array of integers containing the indices of all elements in flags that are in the state passed as argument.
static int[]	getFlagsSetTo(boolean[] flags, int[] indices, boolean state) Returns an array of integers containing the indices of all elements in flags whose index occurs in indices and whose value is state.
static Method	getGetterMethodForClass(Class cls, String beanName) Obtain a (Java bean) getter method from a class or superclasses using reflection.
static String	getJavaBeanGetterName(String fieldName, boolean isBoolean) Generate a JavaBeans compatible getter name
static String	getJavaBeanSetterName(String fieldName) Generate a JavaBeans compatible setter name
static String	getJavaLangClassForType(String type) Convenience method to return the passed type as a java.lang type wherever possible.
static Class	getMapKeyType(Class type, Type genericType) Convenience method to extract the key type of a map when using JDK1.5 generics given the input field.
static String	getMapKeyType(Field field) Convenience method to extract the key type of a map when using JDK1.5 generics given the input field.
static String	getMapKeyType(Method method) Convenience method to extract the key type of a map when using JDK1.5 generics given the input method.
static Class	getMapValueType(Class type, Type genericType) Convenience method to extract the value type of a map when using JDK1.5 generics given the input field
static String	getMapValueType(Field field) Convenience method to extract the value type of a map when using JDK1.5 generics given the input field
static String	getMapValueType(Method method) Convenience method to extract the value type of a map when using JDK1.5 generics given the input method.
static Method	getMethodForClass(Class cls, String methodName, Class[] argtypes) Obtain a method from a class or superclasses using reflection
static Method	getMethodWithArgument(Class cls, String methodName, Class argType) Obtain a method from a class or superclasses using reflection.
static int	getModifiersForFieldOfClass(ClassLoaderResolver clr, String className, String fieldName) Convenience accessor for the modifiers of a field in a class.
static String[]	getPackageJdoFilesForJarFile(String jarFileName) Convenience accessor for the names of all "package.jdo" files in the jar file with the specified name.
static String[]	getPackageJdoFilesForJarFile(URI jarFileURI) Convenience accessor for the names of all "package.jdo" files in the jar file with the specified URL.
static String[]	getPackageJdoFilesForJarFile(URL jarFileURL) Convenience accessor for the names of all "package.jdo" files in the jar file with the specified URL.
static String	getPackageNameForClass(Class cls) Utility to return the package name for a class.
static Class	getPrimitiveTypeForType(Class type) Method to return the primitive equivalent of the specified type (if any).
static Method	getSetterMethodForClass(Class cls, String beanName, Class type) Obtain a (Java bean) setter method from a class or superclasses using reflection.
static Collection<Class<?>>	getSuperclasses(Class<?> the_class) Method to return the superclasses for a class.
static Collection<Class<?>>	getSuperinterfaces(Class<?> the_class) Method to return the superinterfaces for a class.
static Object	getValueForIdentityField(Object id, String fieldName) Method to find the value of a field of the provided user-defined identity.
static Object	getValueOfFieldByReflection(Object object, String fieldName) Helper method to return the value of a field of an object using reflection.
static Object	getValueOfMethodByReflection(Object object, String methodName, Object... args) Helper method to return the value returned by a method on an object using reflection.
static Class	getWrapperTypeForPrimitiveType(Class type) Convenience method to return the object wrapper type for a primitive type.
static String	getWrapperTypeNameForPrimitiveTypeName(String typeName) Convenience method to return the object wrapper type for a primitive type name.
static boolean	hasDefaultConstructor(Class the_class) Method to check for a default constructor on a class.
static boolean	isInnerClass(String class_name) Method to check whether a classname is for an inner class.
static boolean	isJavaBeanGetterMethod(Method method) Convenience method to return if the supplied method is a valid java bean getter method.
static boolean	isPrimitiveArrayType(String typeName) Convenience method to return if the passed type (name) is a primitive array type.
static boolean	isPrimitiveType(String typeName) Convenience method to return if the passed type (name) is a primitive type.
static boolean	isPrimitiveWrapperType(String typeName) Convenience method to return if the passed type (name) is a primitive wrapper type.
static boolean	isReferenceType(Class cls) Method to return whether the passes type is a "reference" type.
static Object	newInstance(Class type, Class[] parameterTypes, Object[] parameters) Accessor for a new instance of an object.
static int	setBitInInt(int bits, int bitIndex, boolean flag) Convenience method to set a boolean as a bit in the specified int, for memory utilisation purposes.
static boolean	stringArrayContainsValue(String[] array, String value) Convenience method to return if a String array contains a value.
static boolean	typesAreCompatible(Class cls1, Class cls2) Convenience method to return if two types are compatible.
static boolean	typesAreCompatible(Class cls1, String clsName2, ClassLoaderResolver clr) Convenience method to return if two types are compatible.

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

Localisation utility for output messages

constructorsCache

protected static final Map constructorsCache

caching for constructors - using caching, the perf is at least doubled

Constructor Detail

ClassUtils

public ClassUtils()

Method Detail

newInstance

public static Object newInstance(Class type,
                 Class[] parameterTypes,
                 Object[] parameters)

Accessor for a new instance of an object. Uses reflection to generate the instance using the passed constructor parameter arguments.

Parameters:

type - Type of object (the class).

parameterTypes - Classes of params for the constructor

parameters - The parameters for the constructor

Returns:

The object

Throws:

NucleusException - If an error occurs creating the instance

getConstructorWithArguments

public static Constructor getConstructorWithArguments(Class cls,
                                      Class[] argTypes)

Convenience method to return the constructor of the passed class that accepts the supplied argument types. Allows for primitive to primitive wrapper conversion. Typically used by the JDOQL ResultClass mapping process.

Parameters:

cls - The class

argTypes - The constructor argument types. If we know we need a parameter yet don't know the type then this will have a null for that argument type.

Returns:

The constructor

getMethodWithArgument

public static Method getMethodWithArgument(Class cls,
                           String methodName,
                           Class argType)

Obtain a method from a class or superclasses using reflection. The method will have the specified name and will take a single argument. Allows for the argument type being primitive or its associated wrapper.

Parameters:

cls - the class to find the declared fields and populate the map

methodName - the method name to find

argType - the argument type

getMethodForClass

public static Method getMethodForClass(Class cls,
                       String methodName,
                       Class[] argtypes)

Obtain a method from a class or superclasses using reflection

Parameters:

cls - the class where to look for the method

methodName - the method name to find

argtypes - the classes argument of the method

Returns:

The Method

getClassnameForFilename

public static String getClassnameForFilename(String filename,
                             String rootfilename)

Utility to get the Class name given the file name and the file name of the root of the package structure.

Parameters:

filename - The filename of the class file

rootfilename - The filename of the root of the package structure

Returns:

The Class name

getClassFilesForDirectory

public static Collection<File> getClassFilesForDirectory(File dir,
                                         boolean normal_classes,
                                         boolean inner_classes)

Method to return the class files below the specified directory.

Parameters:

dir - The directory

normal_classes - Whether to include normal classes

inner_classes - Whether to include inner classes

Returns:

The class files (Collection of File objects).

getFilesForDirectory

public static Collection<File> getFilesForDirectory(File dir)

Method to return the files below the specified directory.

Parameters:

dir - The directory

Returns:

The files

getClassNamesForJarFile

public static String[] getClassNamesForJarFile(String jarFileName)

Convenience accessor for the names of all class files in the jar file with the specified name. The returned class names are of the form "org.datanucleus.MyClass".

Parameters:

jarFileName - Name of the jar file

Returns:

The class names

getClassNamesForJarFile

public static String[] getClassNamesForJarFile(URL jarFileURL)

Convenience accessor for the names of all class files in the jar file with the specified URL. The returned class names are of the form "org.datanucleus.MyClass".

Parameters:

jarFileURL - URL for the jar file

Returns:

The class names

getClassNamesForJarFile

public static String[] getClassNamesForJarFile(URI jarFileURI)

Convenience accessor for the names of all class files in the jar file with the specified URL. The returned class names are of the form "org.datanucleus.MyClass".

Parameters:

jarFileURI - URI for the jar file

Returns:

The class names

getPackageJdoFilesForJarFile

public static String[] getPackageJdoFilesForJarFile(String jarFileName)

Convenience accessor for the names of all "package.jdo" files in the jar file with the specified name.

Parameters:

jarFileName - Name of the jar file

Returns:

The "package.jdo" file names

getPackageJdoFilesForJarFile

public static String[] getPackageJdoFilesForJarFile(URL jarFileURL)

Convenience accessor for the names of all "package.jdo" files in the jar file with the specified URL.

Parameters:

jarFileURL - URL for the jar file

Returns:

The "package.jdo" file names

getPackageJdoFilesForJarFile

public static String[] getPackageJdoFilesForJarFile(URI jarFileURI)

Convenience accessor for the names of all "package.jdo" files in the jar file with the specified URL.

Parameters:

jarFileURI - URI for the jar file

Returns:

The "package.jdo" file names

getClassNamesForDirectoryAndBelow

public static String[] getClassNamesForDirectoryAndBelow(File dir)

Convenience method to return the names of classes specified in the directory and below. All inner classes are ignored.

Parameters:

dir - Directory that we should look below (root of classpath)

Returns:

The class names

isInnerClass

public static boolean isInnerClass(String class_name)

Method to check whether a classname is for an inner class. Currently checks for the presence of $ in the name.

Parameters:

class_name - The class name

Returns:

Whether it is an inner class

hasDefaultConstructor

public static boolean hasDefaultConstructor(Class the_class)

Method to check for a default constructor on a class. Particular relevance for JDO is the requirement for a default constructor on all Persistence-Capable classes. Doesn't check superclasses for the default constructor.

Parameters:

the_class - The class

Returns:

Whether it has a default constructor

getSuperclasses

public static Collection<Class<?>> getSuperclasses(Class<?> the_class)

Method to return the superclasses for a class. The superclasses will be ordered.

Parameters:

the_class - The class

Returns:

The superclass of this class.

getSuperinterfaces

public static Collection<Class<?>> getSuperinterfaces(Class<?> the_class)

Method to return the superinterfaces for a class. The superinterfaces will be ordered and unique.

Parameters:

the_class - The class

Returns:

The superinterfaces of this class.

getFieldForClass

public static Field getFieldForClass(Class cls,
                     String fieldName)

Obtain a field from a class or superclasses using reflection.

Parameters:

cls - the class to find the field from

fieldName - the field name to find

Returns:

The Field

getGetterMethodForClass

public static Method getGetterMethodForClass(Class cls,
                             String beanName)

Obtain a (Java bean) getter method from a class or superclasses using reflection. Any 'get...' method will take precedence over 'is...' methods.

Parameters:

cls - the class to find the getter from

beanName - the name of the java bean to find the getter for

Returns:

The getter Method

getSetterMethodForClass

public static Method getSetterMethodForClass(Class cls,
                             String beanName,
                             Class type)

Obtain a (Java bean) setter method from a class or superclasses using reflection.

Parameters:

cls - the class to find the setter from

beanName - the name of the java bean to find the setter for

type - the type of the java bean to find the setter for

Returns:

The setter Method

getWrapperTypeNameForPrimitiveTypeName

public static String getWrapperTypeNameForPrimitiveTypeName(String typeName)

Convenience method to return the object wrapper type for a primitive type name. If the type is not a primitive then just returns the type name

Parameters:

typeName - The primitive type name

Returns:

The object wrapper type name for this primitive

getWrapperTypeForPrimitiveType

public static Class getWrapperTypeForPrimitiveType(Class type)

Convenience method to return the object wrapper type for a primitive type.

Parameters:

type - The primitive type

Returns:

The object wrapper type for this primitive

getPrimitiveTypeForType

public static Class getPrimitiveTypeForType(Class type)

Method to return the primitive equivalent of the specified type (if any). Returns null if there is no primitive equivalent.

Parameters:

type - The type

Returns:

The primitive equivalent.

isPrimitiveWrapperType

public static boolean isPrimitiveWrapperType(String typeName)

Convenience method to return if the passed type (name) is a primitive wrapper type.

Parameters:

typeName - Name of the type

Returns:

Whether it is a primitive wrapper

isPrimitiveArrayType

public static boolean isPrimitiveArrayType(String typeName)

Convenience method to return if the passed type (name) is a primitive array type.

Parameters:

typeName - Name of the type

Returns:

Whether it is a primitive array

isPrimitiveType

public static boolean isPrimitiveType(String typeName)

Convenience method to return if the passed type (name) is a primitive type.

Parameters:

typeName - Name of the type

Returns:

Whether it is a primitive

convertValue

public static Object convertValue(Object value,
                  Class cls)

Convenience method to convert the passed value to an object of the specified type (if possible). If no such conversion is supported will return null. If the required type is a primitive will return an object of the wrapper type.

Parameters:

value - The value

cls - The class

Returns:

The converted value (or null)

typesAreCompatible

public static boolean typesAreCompatible(Class cls1,
                         String clsName2,
                         ClassLoaderResolver clr)

Convenience method to return if two types are compatible. Returns true if both types are primitive/wrappers and are of the same type. Returns true if clsName2 is the same or a subclass of cls1. Otherwise returns false;

Parameters:

cls1 - First class

clsName2 - Name of the second class

clr - ClassLoader resolver to use

Returns:

Whether they are compatible

typesAreCompatible

public static boolean typesAreCompatible(Class cls1,
                         Class cls2)

Convenience method to return if two types are compatible. Returns true if both types are primitive/wrappers and are of the same type. Returns true if cls2 is the same or a subclass of cls1. Otherwise returns false;

Parameters:

cls1 - First class

cls2 - Second class

Returns:

Whether they are compatible

createFullClassName

public static String createFullClassName(String pkg_name,
                         String cls_name)

Utility to create the full class name given the package and class name. Some examples

 packageName=test className=Test, returns result=test.Test
 packageName=test className=test1.Test, returns result=test1.Test
 packageName=<null> className=Test, returns result=Test
 packageName=<null> className=test1.Test, returns result=test1.Test
 

Parameters:

pkg_name - package name.

cls_name - class name.

Returns:

generated full class name.

getJavaLangClassForType

public static String getJavaLangClassForType(String type)

Convenience method to return the passed type as a java.lang type wherever possible. The passed type will be stripped of any package name and will be checked if it is a known java.lang class. This is used where the user has specified a class name for a collection or map element/key/value type and meant a java.lang class but didn't fully qualify it.

Parameters:

type - The type name

Returns:

The java.lang equivalent (or the input type if not possible)

classesAreDescendents

public static boolean classesAreDescendents(ClassLoaderResolver clr,
                            String class_name_1,
                            String class_name_2)

Method to check if 2 classes are direct descendents. So one of them is a superclass of the other.

Parameters:

clr - ClassLoaderResolver for loading the classes

class_name_1 - Name of first class

class_name_2 - Name of second class

Returns:

Whether they are direct descendents.

dumpClassInformation

public static void dumpClassInformation(Class cls)

Utility to use Reflection to dump out the details of a class. Will list all superclasses, interfaces, methods and fields. Can be used, for example, in checking the methods adding by the enhancement process. The information is dumped out the GENERAL log.

Parameters:

cls - The class to dump out to the log

getJavaBeanGetterName

public static String getJavaBeanGetterName(String fieldName,
                           boolean isBoolean)

Generate a JavaBeans compatible getter name

Parameters:

fieldName - the field name

isBoolean - whether the field is primitive boolean type

Returns:

the getter name

getJavaBeanSetterName

public static String getJavaBeanSetterName(String fieldName)

Generate a JavaBeans compatible setter name

Parameters:

fieldName - the field name

Returns:

the setter name

getFieldNameForJavaBeanGetter

public static String getFieldNameForJavaBeanGetter(String methodName)

Generate a field name for JavaBeans compatible getter method

Parameters:

methodName - the method name

Returns:

the field name

getFieldNameForJavaBeanSetter

public static String getFieldNameForJavaBeanSetter(String methodName)

Generate a field name for JavaBeans compatible setter method

Parameters:

methodName - the method name

Returns:

the field name

getClassNameForFileName

public static String getClassNameForFileName(String fileName,
                             ClassLoaderResolver clr)

Convenience method to try to find the class name stored in the specified file. Moves along the file, chopping off components from the front until it finds a class in the class path. This is typically used as a fallback after trying the method after this.

Parameters:

fileName - Name of file

clr - ClassLoader resolver

Returns:

The class name (if found)

getClassNameForFileURL

public static String getClassNameForFileURL(URL fileURL)
                                     throws ClassNotFoundException

Utility to find the class name of a class given the absolute file name of its class file. Creates a loader and loads the class directly to find it.

Parameters:

fileURL - URL for the class file

Returns:

The name of the class

Throws:

ClassNotFoundException - Thrown when the file is not found

getPackageNameForClass

public static String getPackageNameForClass(Class cls)

Utility to return the package name for a class. Allows for the result of class.getPackage() being null.

Parameters:

cls - The class

Returns:

The name of its package (or null if no package e.g a primitive)

getClassNameForClass

public static String getClassNameForClass(Class cls)

Utility to return the class name without the package name for a class.

Parameters:

cls - The class

Returns:

The name of the class without its package

getClassForGenericType

public static Class getClassForGenericType(Type genericType,
                           int pos)

Convenience method to attempt to return the class for the provided generic type.

Parameters:

genericType - The generic type

pos - The position of the generic arg (in case of multiple)

Returns:

The class (if determinable), or null

getCollectionElementType

public static String getCollectionElementType(Field field)

Convenience method to extract the element type of a collection when using JDK1.5 generics given the input field.

Parameters:

field - The field

Returns:

The name of the element class

getCollectionElementType

public static String getCollectionElementType(Method method)

Convenience method to extract the element type of a collection when using JDK1.5 generics, given the input method (getter).

Parameters:

method - The method

Returns:

The name of the element class

getCollectionElementType

public static Class getCollectionElementType(Class type,
                             Type genericType)

Convenience method to extract the element type of a collection when using JDK1.5 generics given the input field.

Parameters:

type - the field type

genericType - the generic type

Returns:

The element class

getMapKeyType

public static String getMapKeyType(Field field)

Convenience method to extract the key type of a map when using JDK1.5 generics given the input field.

Parameters:

field - The field

Returns:

The name of the key class

getMapKeyType

public static String getMapKeyType(Method method)

Convenience method to extract the key type of a map when using JDK1.5 generics given the input method.

Parameters:

method - The method

Returns:

The name of the key class

getMapKeyType

public static Class getMapKeyType(Class type,
                  Type genericType)

Convenience method to extract the key type of a map when using JDK1.5 generics given the input field.

Parameters:

type - the field type

genericType - the generic type

Returns:

The name of the key class

getMapValueType

public static String getMapValueType(Field field)

Convenience method to extract the value type of a map when using JDK1.5 generics given the input field

Parameters:

field - The field

Returns:

The name of the value class

getMapValueType

public static String getMapValueType(Method method)

Convenience method to extract the value type of a map when using JDK1.5 generics given the input method.

Parameters:

method - The method

Returns:

The name of the value class

getMapValueType

public static Class getMapValueType(Class type,
                    Type genericType)

Convenience method to extract the value type of a map when using JDK1.5 generics given the input field

Parameters:

type - the field type

genericType - the generic type

Returns:

The name of the value class

getModifiersForFieldOfClass

public static int getModifiersForFieldOfClass(ClassLoaderResolver clr,
                              String className,
                              String fieldName)

Convenience accessor for the modifiers of a field in a class.

Parameters:

clr - ClassLoader resolver

className - Name of the class

fieldName - Name of the field

Returns:

The modifiers

isReferenceType

public static boolean isReferenceType(Class cls)

Method to return whether the passes type is a "reference" type. A "reference" type is either an interface or an Object, so can be used as a reference to a persistable object.

Parameters:

cls - The type

Returns:

Whether it is a reference type

assertClassForJarExistsInClasspath

public static void assertClassForJarExistsInClasspath(ClassLoaderResolver clr,
                                      String className,
                                      String jarName)

Convenience method to throw a NucleusUserException if the specified class is not loadable from the ClassLoaderResolver.

Parameters:

clr - ClassLoader resolver

className - Name of the class

jarName - Name of the jar containing the class

Throws:

NucleusUserException - if the class is not found

stringArrayContainsValue

public static boolean stringArrayContainsValue(String[] array,
                               String value)

Convenience method to return if a String array contains a value.

Parameters:

array - The String array

value - The value

Returns:

Whether it is contained

getValueOfMethodByReflection

public static Object getValueOfMethodByReflection(Object object,
                                  String methodName,
                                  Object... args)

Helper method to return the value returned by a method on an object using reflection.

Parameters:

object - The object

methodName - Name of the method

Returns:

The value

getValueOfFieldByReflection

public static Object getValueOfFieldByReflection(Object object,
                                 String fieldName)

Helper method to return the value of a field of an object using reflection.

Parameters:

object - The object

fieldName - Name of the field

Returns:

The value

getValueForIdentityField

public static Object getValueForIdentityField(Object id,
                              String fieldName)

Method to find the value of a field of the provided user-defined identity. The field has to be either accessible, or have a Java-bean style getter.

Parameters:

id - The identity

fieldName - Name of the field

Returns:

The value of the field in this identity

Throws:

NucleusUserException - if not possible to get the value

getClassForMemberOfClass

public static Class getClassForMemberOfClass(Class cls,
                             String memberName)

Method that returns the class type of a member of the specified class (if present). The member can either be a field, or a Java bean name (for a getter).

Parameters:

cls - The class

memberName - The member name

Returns:

The member class (or null if not present)

isJavaBeanGetterMethod

public static boolean isJavaBeanGetterMethod(Method method)

Convenience method to return if the supplied method is a valid java bean getter method. Checks that it is not static, that its name starts "get" or "is", that it has a return type and that it takes no arguments.

Parameters:

method - The method

Returns:

Whether this method is a java bean getter

clearFlags

public static void clearFlags(boolean[] flags)

Utility to clear the supplied flags.

Parameters:

flags -

clearFlags

public static void clearFlags(boolean[] flags,
              int[] fields)

Utility to clear the supplied flags.

Parameters:

flags -

fields - fields numbers where the flags will be cleared

getFlagsSetTo

public static int[] getFlagsSetTo(boolean[] flags,
                  boolean state)

Returns an array of integers containing the indices of all elements in flags that are in the state passed as argument.

Parameters:

flags - Array of flags (true or false)

state - The state to search (true or false)

Returns:

The settings of the flags

getFlagsSetTo

public static int[] getFlagsSetTo(boolean[] flags,
                  int[] indices,
                  boolean state)

Returns an array of integers containing the indices of all elements in flags whose index occurs in indices and whose value is state.

getBitFromInt

public static boolean getBitFromInt(int bits,
                    int bitIndex)

Convenience method to get the value of a bit from an int when we are storing (up to 32) boolean in an int for memory utilisation purposes.

Parameters:

bits - The int storing the bits

bitIndex - The index of this bit

Returns:

The value of this bit (as a boolean)

setBitInInt

public static int setBitInInt(int bits,
              int bitIndex,
              boolean flag)

Convenience method to set a boolean as a bit in the specified int, for memory utilisation purposes.

Parameters:

bits - The int storing the bits

bitIndex - The index of this bit

flag - The boolean value to store

Returns:

The int with this bit set