com.fasterxml.jackson.databind.util

Class ClassUtil

java.lang.Object

com.fasterxml.jackson.databind.util.ClassUtil

public final class ClassUtil
extends Object

Constructor Summary

Constructors

Constructor and Description
ClassUtil()

Method Summary

Methods

Modifier and Type	Method and Description
static String	canBeABeanType(Class<?> type)
static void	checkAndFixAccess(Member member) Method called to check if we can use the passed method or constructor (wrt access restriction -- public methods can be called, others usually not); and if not, if there is a work-around for the problem.
static <T> T	createInstance(Class<T> cls, boolean canFixAccess) Method that can be called to try to create an instantiate of specified type.
static Object	defaultValue(Class<?> cls) Helper method used to get default value for wrappers used for primitive types (0 for Integer etc)
static Class<?>	findClass(String className)
static <T> Constructor<T>	findConstructor(Class<T> cls, boolean canFixAccess)
static Class<? extends Enum<?>>	findEnumType(Class<?> cls) Helper method that can be used to dynamically figure out formal enumeration type (class) for given class of an enumeration value.
static Class<? extends Enum<?>>	findEnumType(Enum<?> en) Helper method that can be used to dynamically figure out formal enumeration type (class) for given enumeration.
static Class<? extends Enum<?>>	findEnumType(EnumMap<?,?> m) Helper method that can be used to dynamically figure out enumeration type of given EnumSet, without having access to its declaration.
static Class<? extends Enum<?>>	findEnumType(EnumSet<?> s) Helper method that can be used to dynamically figure out enumeration type of given EnumSet, without having access to its declaration.
static List<Class<?>>	findSuperTypes(Class<?> cls, Class<?> endBefore) Method that will find all sub-classes and implemented interfaces of a given class or interface.
static List<Class<?>>	findSuperTypes(Class<?> cls, Class<?> endBefore, List<Class<?>> result)
static String	getClassDescription(Object classOrInstance) Helper method used to construct appropriate description when passed either type (Class) or an instance; in latter case, class of instance is to be used.
static Class<?>	getOuterClass(Class<?> type) Method for finding enclosing class for non-static inner classes
static Throwable	getRootCause(Throwable t) Method that can be used to find the "root cause", innermost of chained (wrapped) exceptions.
static boolean	hasGetterSignature(Method m)
static boolean	isBogusClass(Class<?> cls)
static boolean	isCollectionMapOrArray(Class<?> type)
static boolean	isConcrete(Class<?> type) Helper method that checks if given class is a concrete one; that is, not an interface or abstract class.
static boolean	isConcrete(Member member)
static boolean	isJacksonStdImpl(Class<?> implClass)
static boolean	isJacksonStdImpl(Object impl) Method that can be called to determine if given Object is the default implementation Jackson uses; as opposed to a custom serializer installed by a module or calling application.
static String	isLocalType(Class<?> type, boolean allowNonStatic)
static boolean	isProxyType(Class<?> type) Helper method used to weed out dynamic Proxy types; types that do not expose concrete method API that we could use to figure out automatic Bean (property) based serialization.
static void	throwAsIAE(Throwable t) Method that will wrap 't' as an IllegalArgumentException if it is a checked exception; otherwise (runtime exception or error) throw as is
static void	throwAsIAE(Throwable t, String msg) Method that will wrap 't' as an IllegalArgumentException (and with specified message) if it is a checked exception; otherwise (runtime exception or error) throw as is
static void	throwRootCause(Throwable t) Method that will unwrap root causes of given Throwable, and throw the innermost Exception or Error as is.
static void	unwrapAndThrowAsIAE(Throwable t) Method that will locate the innermost exception for given Throwable; and then wrap it as an IllegalArgumentException if it is a checked exception; otherwise (runtime exception or error) throw as is
static void	unwrapAndThrowAsIAE(Throwable t, String msg) Method that will locate the innermost exception for given Throwable; and then wrap it as an IllegalArgumentException if it is a checked exception; otherwise (runtime exception or error) throw as is
static Class<?>	wrapperType(Class<?> primitiveType) Helper method for finding wrapper type for given primitive type (why isn't there one in JDK?)

Methods inherited from class java.lang.Object

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

Constructor Detail

ClassUtil

public ClassUtil()

Method Detail

findSuperTypes

public static List<Class<?>> findSuperTypes(Class<?> cls,
                            Class<?> endBefore)

Method that will find all sub-classes and implemented interfaces of a given class or interface. Classes are listed in order of precedence, starting with the immediate super-class, followed by interfaces class directly declares to implemented, and then recursively followed by parent of super-class and so forth. Note that Object.class is not included in the list regardless of whether endBefore argument is defined or not.

Parameters:

endBefore - Super-type to NOT include in results, if any; when encountered, will be ignored (and no super types are checked).

findSuperTypes

public static List<Class<?>> findSuperTypes(Class<?> cls,
                            Class<?> endBefore,
                            List<Class<?>> result)

canBeABeanType

public static String canBeABeanType(Class<?> type)

Returns:

Null if class might be a bean; type String (that identifies why it's not a bean) if not

isLocalType

public static String isLocalType(Class<?> type,
                 boolean allowNonStatic)

getOuterClass

public static Class<?> getOuterClass(Class<?> type)

Method for finding enclosing class for non-static inner classes

isProxyType

public static boolean isProxyType(Class<?> type)

Helper method used to weed out dynamic Proxy types; types that do not expose concrete method API that we could use to figure out automatic Bean (property) based serialization.

isConcrete

public static boolean isConcrete(Class<?> type)

Helper method that checks if given class is a concrete one; that is, not an interface or abstract class.

isConcrete

public static boolean isConcrete(Member member)

isCollectionMapOrArray

public static boolean isCollectionMapOrArray(Class<?> type)

getClassDescription

public static String getClassDescription(Object classOrInstance)

Helper method used to construct appropriate description when passed either type (Class) or an instance; in latter case, class of instance is to be used.

findClass

public static Class<?> findClass(String className)
                          throws ClassNotFoundException

Throws:

ClassNotFoundException

hasGetterSignature

public static boolean hasGetterSignature(Method m)

getRootCause

public static Throwable getRootCause(Throwable t)

Method that can be used to find the "root cause", innermost of chained (wrapped) exceptions.

throwRootCause

public static void throwRootCause(Throwable t)
                           throws Exception

Method that will unwrap root causes of given Throwable, and throw the innermost Exception or Error as is. This is useful in cases where mandatory wrapping is added, which is often done by Reflection API.

Throws:

Exception

throwAsIAE

public static void throwAsIAE(Throwable t)

Method that will wrap 't' as an IllegalArgumentException if it is a checked exception; otherwise (runtime exception or error) throw as is

throwAsIAE

public static void throwAsIAE(Throwable t,
              String msg)

Method that will wrap 't' as an IllegalArgumentException (and with specified message) if it is a checked exception; otherwise (runtime exception or error) throw as is

unwrapAndThrowAsIAE

public static void unwrapAndThrowAsIAE(Throwable t)

Method that will locate the innermost exception for given Throwable; and then wrap it as an IllegalArgumentException if it is a checked exception; otherwise (runtime exception or error) throw as is

unwrapAndThrowAsIAE

public static void unwrapAndThrowAsIAE(Throwable t,
                       String msg)

Method that will locate the innermost exception for given Throwable; and then wrap it as an IllegalArgumentException if it is a checked exception; otherwise (runtime exception or error) throw as is

createInstance

public static <T> T createInstance(Class<T> cls,
                   boolean canFixAccess)
                        throws IllegalArgumentException

Method that can be called to try to create an instantiate of specified type. Instantiation is done using default no-argument constructor.

Parameters:

canFixAccess - Whether it is possible to try to change access rights of the default constructor (in case it is not publicly accessible) or not.

Throws:

IllegalArgumentException - If instantiation fails for any reason; except for cases where constructor throws an unchecked exception (which will be passed as is)

findConstructor

public static <T> Constructor<T> findConstructor(Class<T> cls,
                                 boolean canFixAccess)
                                      throws IllegalArgumentException

Throws:

IllegalArgumentException

defaultValue

public static Object defaultValue(Class<?> cls)

Helper method used to get default value for wrappers used for primitive types (0 for Integer etc)

wrapperType

public static Class<?> wrapperType(Class<?> primitiveType)

Helper method for finding wrapper type for given primitive type (why isn't there one in JDK?)

checkAndFixAccess

public static void checkAndFixAccess(Member member)

Method called to check if we can use the passed method or constructor (wrt access restriction -- public methods can be called, others usually not); and if not, if there is a work-around for the problem.

findEnumType

public static Class<? extends Enum<?>> findEnumType(EnumSet<?> s)

Helper method that can be used to dynamically figure out enumeration type of given EnumSet, without having access to its declaration. Code is needed to work around design flaw in JDK.

findEnumType

public static Class<? extends Enum<?>> findEnumType(EnumMap<?,?> m)

Helper method that can be used to dynamically figure out enumeration type of given EnumSet, without having access to its declaration. Code is needed to work around design flaw in JDK.

findEnumType

public static Class<? extends Enum<?>> findEnumType(Enum<?> en)

Helper method that can be used to dynamically figure out formal enumeration type (class) for given enumeration. This is either class of enum instance (for "simple" enumerations), or its superclass (for enums with instance fields or methods)

findEnumType

public static Class<? extends Enum<?>> findEnumType(Class<?> cls)

Helper method that can be used to dynamically figure out formal enumeration type (class) for given class of an enumeration value. This is either class of enum instance (for "simple" enumerations), or its superclass (for enums with instance fields or methods)

isJacksonStdImpl

public static boolean isJacksonStdImpl(Object impl)

Method that can be called to determine if given Object is the default implementation Jackson uses; as opposed to a custom serializer installed by a module or calling application. Determination is done using JacksonStdImpl annotation on handler (serializer, deserializer etc) class.

isJacksonStdImpl

public static boolean isJacksonStdImpl(Class<?> implClass)

isBogusClass

public static final boolean isBogusClass(Class<?> cls)