ClassUtils (DataNucleus Core 3.2.15 API)

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()

Constructors
Constructor and Description
`ClassUtils()`

Method Summary

All Methods Static Methods Concrete 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

Class ClassUtils

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

LOCALISER

constructorsCache

Constructor Detail

ClassUtils

Method Detail

newInstance

getConstructorWithArguments

getMethodWithArgument

getMethodForClass

getClassnameForFilename

getClassFilesForDirectory

getFilesForDirectory

getClassNamesForJarFile

getClassNamesForJarFile

getClassNamesForJarFile

getPackageJdoFilesForJarFile

getPackageJdoFilesForJarFile

getPackageJdoFilesForJarFile

getClassNamesForDirectoryAndBelow

isInnerClass

hasDefaultConstructor

getSuperclasses

getSuperinterfaces

getFieldForClass

getGetterMethodForClass

getSetterMethodForClass

getWrapperTypeNameForPrimitiveTypeName

getWrapperTypeForPrimitiveType

getPrimitiveTypeForType

isPrimitiveWrapperType

isPrimitiveArrayType

isPrimitiveType

convertValue

typesAreCompatible

typesAreCompatible

createFullClassName

getJavaLangClassForType

classesAreDescendents

dumpClassInformation

getJavaBeanGetterName

getJavaBeanSetterName

getFieldNameForJavaBeanGetter

getFieldNameForJavaBeanSetter

getClassNameForFileName

getClassNameForFileURL

getPackageNameForClass

getClassNameForClass

getClassForGenericType

getCollectionElementType

getCollectionElementType

getCollectionElementType

getMapKeyType

getMapKeyType

getMapKeyType

getMapValueType

getMapValueType

getMapValueType

getModifiersForFieldOfClass

isReferenceType

assertClassForJarExistsInClasspath

stringArrayContainsValue

getValueOfMethodByReflection

getValueOfFieldByReflection

getValueForIdentityField

getClassForMemberOfClass

isJavaBeanGetterMethod

clearFlags

clearFlags

getFlagsSetTo

getFlagsSetTo

getBitFromInt

setBitInInt