ClassUtil (Jackson JSON Processor)
Date: 2013-07-14

org.codehaus.jackson.map.util

## Class ClassUtil

- java.lang.Object
- - org.codehaus.jackson.map.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` | `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 String` | `isLocalType(Class<?> type)` Deprecated. since 1.9, use variant that takes second argument
    `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

          @Deprecated
          public static String isLocalType(Class<?> type)

      Deprecated. since 1.9, use variant that takes second argument

    - #### isLocalType

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

      Since:
        1.9

    - #### getOuterClass

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

      Method for finding enclosing class for non-static inner classes
      Since:
        1.9

    - #### 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)

      Since:
        1.6

    - #### 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`
      Since:
        1.7

    - #### 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)
      Since:
        1.6.1

    - #### wrapperType

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

      Helper method for finding wrapper type for given primitive type (why isn't there one in JDK?)
      Since:
        1.7.1

    - #### 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.
      Since:
        1.5

    - #### 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.
      Since:
        1.5

    - #### 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)