com.helger.commons.lang

Class ClassHelper

java.lang.Object

com.helger.commons.lang.ClassHelper

@Immutable
public final class ClassHelper
extends Object

Class helper methods.

Author:

Philip Helger

Method Summary

Modifier and Type	Method and Description
static boolean	areConvertibleClasses(Class<?> aSrcClass, Class<?> aDstClass) Check if the passed classes are convertible.
static ICommonsSet<Class<?>>	getAllPrimitiveClasses()
static ICommonsSet<Class<?>>	getAllPrimitiveWrapperClasses()
static Class<?>	getClass(Object aObject) null-safe helper method to determine the class of an object.
static String	getClassFromPath(String sPath) Get the class name of the passed path.
static String	getClassLocalName(Class<?> aClass) Get the name of the class without the package.
static String	getClassLocalName(Object aObject) Get the name of the object's class without the package.
static String	getClassLocalName(String sClassName) Get the name of the class without the package.
static String	getClassName(Object aObject) null-safe helper method to determine the class name of an object.
static String	getClassPackageName(Class<?> aClass) Get the name of the package the passed class resides in.
static String	getClassPackageName(Object aObject) Get the name of the package the passed object resides in.
static String	getClassPackageName(String sClassName) Get the name of the package the passed class resides in.
static String	getDirectoryFromPackage(Package aPackage) Convert a package name to a relative directory name.
static String	getDirectoryFromPackage(String sPackage) Convert a package name to a relative directory name.
static String	getObjectAddress(Object aObject) Get the hex representation of the passed object's address.
static String	getPathFromClass(Class<?> aClass) Get the path representation of the passed class.
static String	getPathFromClass(String sClassName) Get the path representation of the passed class name.
static Class<?>	getPrimitiveClass(Class<?> aClass) Get the primitive class of the passed primitive wrapper class.
static Class<?>	getPrimitiveWrapperClass(Class<?> aClass) Get the primitive wrapper class of the passed primitive class.
static URL	getResource(Class<?> aClass, String sPath) Get the URL of the passed resource using the class loader of the specified class only.
static InputStream	getResourceAsStream(Class<?> aClass, String sPath) Get the input stream of the passed resource using the class loader of the specified class only.
static String	getSafeClassName(Object aObject) Get the class name of the passed object.
static boolean	isAbstractClass(Class<?> aClass) Check if the passed class is abstract or not.
static boolean	isAnnotationClass(Class<?> aClass)
static boolean	isArrayClass(Class<?> aClass)
static boolean	isBooleanClass(Class<?> aClass)
static boolean	isCharacterClass(Class<?> aClass)
static boolean	isEnumClass(Class<?> aClass)
static boolean	isFloatingPointClass(Class<?> aClass)
static boolean	isInstancableClass(Class<?> aClass) Check if the passed class is public, instancable and has a no-argument constructor.
static boolean	isIntegerClass(Class<?> aClass)
static boolean	isInterface(Class<?> aClass) Check if the passed class is an interface or not.
static boolean	isPrimitiveType(Class<?> aClass)
static boolean	isPrimitiveWrapperType(Class<?> aClass)
static boolean	isPublic(Class<?> aClass)
static boolean	isPublicClass(Class<?> aClass)
static boolean	isStringClass(Class<?> aClass)

Methods inherited from class java.lang.Object

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

Method Detail

isPublicClass

public static boolean isPublicClass(@Nullable
                                    Class<?> aClass)

isInstancableClass

public static boolean isInstancableClass(@Nullable
                                         Class<?> aClass)

Check if the passed class is public, instancable and has a no-argument constructor.

Parameters:

aClass - The class to check. May be null.

Returns:

true if the class is public, instancable and has a no-argument constructor that is public.

isPublic

public static boolean isPublic(@Nullable
                               Class<?> aClass)

isInterface

public static boolean isInterface(@Nullable
                                  Class<?> aClass)

Check if the passed class is an interface or not. Please note that annotations are also interfaces!

Parameters:

aClass - The class to check.

Returns:

true if the class is an interface (or an annotation)

isAnnotationClass

public static boolean isAnnotationClass(@Nullable
                                        Class<?> aClass)

isEnumClass

public static boolean isEnumClass(@Nullable
                                  Class<?> aClass)

isAbstractClass

public static boolean isAbstractClass(@Nullable
                                      Class<?> aClass)

Check if the passed class is abstract or not. Note: interfaces and annotations are also considered as abstract whereas arrays are never abstract.

Parameters:

aClass - The class to check.

Returns:

true if the passed class is abstract

isArrayClass

public static boolean isArrayClass(@Nullable
                                   Class<?> aClass)

isPrimitiveType

public static boolean isPrimitiveType(@Nullable
                                      Class<?> aClass)

isPrimitiveWrapperType

public static boolean isPrimitiveWrapperType(@Nullable
                                             Class<?> aClass)

getPrimitiveWrapperClass

@Nullable
public static Class<?> getPrimitiveWrapperClass(@Nullable
                                                           Class<?> aClass)

Get the primitive wrapper class of the passed primitive class.

Parameters:

aClass - The primitive class. May be null.

Returns:

null if the passed class is not a primitive class.

getPrimitiveClass

@Nullable
public static Class<?> getPrimitiveClass(@Nullable
                                                    Class<?> aClass)

Get the primitive class of the passed primitive wrapper class.

Parameters:

aClass - The primitive wrapper class. May be null.

Returns:

null if the passed class is not a primitive wrapper class.

getAllPrimitiveClasses

@Nonnull
 @ReturnsMutableCopy
public static ICommonsSet<Class<?>> getAllPrimitiveClasses()

getAllPrimitiveWrapperClasses

@Nonnull
 @ReturnsMutableCopy
public static ICommonsSet<Class<?>> getAllPrimitiveWrapperClasses()

isStringClass

public static boolean isStringClass(@Nullable
                                    Class<?> aClass)

isCharacterClass

public static boolean isCharacterClass(@Nullable
                                       Class<?> aClass)

isBooleanClass

public static boolean isBooleanClass(@Nullable
                                     Class<?> aClass)

isFloatingPointClass

public static boolean isFloatingPointClass(@Nullable
                                           Class<?> aClass)

isIntegerClass

public static boolean isIntegerClass(@Nullable
                                     Class<?> aClass)

areConvertibleClasses

public static boolean areConvertibleClasses(@Nonnull
                                            Class<?> aSrcClass,
                                            @Nonnull
                                            Class<?> aDstClass)

Check if the passed classes are convertible. Includes conversion checks between primitive types and primitive wrapper types.

Parameters:

aSrcClass - First class. May not be null.

aDstClass - Second class. May not be null.

Returns:

true if the classes are directly convertible.

getClass

@Nullable
public static Class<?> getClass(@Nullable
                                           Object aObject)

null-safe helper method to determine the class of an object.

Parameters:

aObject - The object to query. May be null.

Returns:

null if the passed object is null.

getClassName

@Nullable
public static String getClassName(@Nullable
                                             Object aObject)

null-safe helper method to determine the class name of an object.

Parameters:

aObject - The object to query. May be null.

Returns:

null if the passed object is null.

getClassLocalName

@Nullable
public static String getClassLocalName(@Nullable
                                                  Object aObject)

Get the name of the object's class without the package.

Parameters:

aObject - The object to get the information from. May be null .

Returns:

The local name of the passed object's class.

getClassLocalName

@Nullable
public static String getClassLocalName(@Nullable
                                                  Class<?> aClass)

Get the name of the class without the package.

Parameters:

aClass - The class to get the information from. May be null.

Returns:

The local name of the passed class.

getClassLocalName

@Nullable
public static String getClassLocalName(@Nullable
                                                  String sClassName)

Get the name of the class without the package.

Parameters:

sClassName - The fully qualified name of the class. May be null.

Returns:

The local name of the passed class. Never null.

getClassPackageName

@Nullable
public static String getClassPackageName(@Nullable
                                                    Object aObject)

Get the name of the package the passed object resides in.

Parameters:

aObject - The class to get the information from. May be null.

Returns:

The package name of the passed object.

getClassPackageName

@Nullable
public static String getClassPackageName(@Nullable
                                                    Class<?> aClass)

Get the name of the package the passed class resides in.

Parameters:

aClass - The class to get the information from. May not be null.

Returns:

The package name of the passed class.

getClassPackageName

@Nullable
public static String getClassPackageName(@Nullable
                                                    String sClassName)

Get the name of the package the passed class resides in.

Parameters:

sClassName - The name class to get the information from. May be null .

Returns:

The package name of the passed class.

getSafeClassName

@Nonnull
 @Nonempty
public static String getSafeClassName(@Nullable
                                                            Object aObject)

Get the class name of the passed object. If the object itself is of type Class, its name is retrieved, other Object.getClass() is called.

Parameters:

aObject - The object who's class name is to be retrieved.

Returns:

"null" for a null parameter

getDirectoryFromPackage

@Nullable
public static String getDirectoryFromPackage(@Nullable
                                                        Package aPackage)

Convert a package name to a relative directory name.

Parameters:

aPackage - The package to be converted. May be null.

Returns:

The directory name using forward slashes (/) instead of the dots.

getDirectoryFromPackage

@Nullable
public static String getDirectoryFromPackage(@Nullable
                                                        String sPackage)

Convert a package name to a relative directory name.

Parameters:

sPackage - The name of the package to be converted. May be null.

Returns:

The directory name using forward slashes (/) instead of the dots.

getPathFromClass

@Nullable
public static String getPathFromClass(@Nullable
                                                 Class<?> aClass)

Get the path representation of the passed class. The path representation is achieved by replacing all dots (.) with forward slashes (/) in the class name.

Parameters:

aClass - The class of which the path is to be retrieved. May be null.

Returns:

The path representation. Never null.

getPathFromClass

@Nullable
public static String getPathFromClass(@Nullable
                                                 String sClassName)

Get the path representation of the passed class name. The path representation is achieved by replacing all dots (.) with forward slashes (/) in the class name.

Parameters:

sClassName - The class name of which the path is to be retrieved. May be null.

Returns:

The path representation

getClassFromPath

@Nullable
public static String getClassFromPath(@Nullable
                                                 String sPath)

Get the class name of the passed path. The class name is retrieved by replacing all path separators (\ and /) with dots (.). This method does not handle the file extension, so it's up to the caller to skip of any file extension!

Parameters:

sPath - The path to be converted. May be null.

Returns:

The class name.

getObjectAddress

@Nonnull
 @Nonempty
public static String getObjectAddress(@Nullable
                                                            Object aObject)

Get the hex representation of the passed object's address. Note that this method makes no differentiation between 32 and 64 bit architectures. The result is always a hexadecimal value preceded by "0x" and followed by exactly 8 characters.

Parameters:

aObject - The object who's address is to be retrieved. May be null.

Returns:

Depending on the current architecture. Always starting with "0x" and than containing the address.

See Also:

System.identityHashCode(Object)

getResource

@Nullable
public static URL getResource(@Nonnull
                                         Class<?> aClass,
                                         @Nonnull @Nonempty
                                         String sPath)

Get the URL of the passed resource using the class loader of the specified class only. This is a sanity wrapper around class.getResource (sPath).

Parameters:

aClass - The class to be used. May not be null.

sPath - The path to be resolved. May neither be null nor empty. Internally it is ensured that the provided path does start with a slash.

Returns:

null if the path could not be resolved using the specified class loader.

getResourceAsStream

@Nullable
public static InputStream getResourceAsStream(@Nonnull
                                                         Class<?> aClass,
                                                         @Nonnull @Nonempty
                                                         String sPath)

Get the input stream of the passed resource using the class loader of the specified class only. This is a sanity wrapper around class.getResourceAsStream (sPath).

Parameters:

aClass - The class to be used. May not be null.

sPath - The path to be resolved. May neither be null nor empty. Internally it is ensured that the provided path does start with a slash.

Returns:

null if the path could not be resolved using the specified class loader.