public abstract class ReflectionUtils extends Object
Simple utility class for working with the reflection API and handling reflection exceptions.

Only intended for internal use.

Since:
1.2.2
Author:
Juergen Hoeller, Rob Harrop, Rod Johnson, Costin Leau, Sam Brannen, Chris Beams
Callback optionally used to filter fields to be operated on by a field callback.
static interface
Action to take on each method.
static interface
Callback optionally used to filter methods to be operated on by a method callback.
Pre-built FieldFilter that matches all non-static, non-final fields.
Pre-built ReflectionUtils.MethodFilter that matches all non-bridge non-synthetic methods which are not declared on java.lang.Object .
static <T> Constructor <T>
accessibleConstructor ( Class <T> clazz, Class <?>... parameterTypes)
Obtain an accessible constructor for the given class and parameters.
static void
Clear the internal method/field cache.
static boolean
declaresException ( Method method, Class <?> exceptionType)
Determine whether the given method explicitly declares the given exception or one of its superclasses, which means that an exception of that type can be propagated as-is within a reflective invocation.
static void
Invoke the given callback on all fields in the target class, going up the class hierarchy to get all declared fields.
static void
Invoke the given callback on all fields in the target class, going up the class hierarchy to get all declared fields.
static void
Invoke the given callback on all locally declared fields in the given class.
static void
Perform the given callback operation on all matching methods of the given class, as locally declared or equivalent thereof (such as default methods on Java 8 based interfaces that the given class implements).
static void
Perform the given callback operation on all matching methods of the given class and superclasses.
static void
Perform the given callback operation on all matching methods of the given class and superclasses (or given interface and super-interfaces).
static Field
findField ( Class <?> clazz, String name)
Attempt to find a field on the supplied Class with the supplied name .
static Field
findField ( Class <?> clazz, String name, Class <?> type)
Attempt to find a field on the supplied Class with the supplied name and/or type .
static Method
findMethod ( Class <?> clazz, String name)
Attempt to find a Method on the supplied class with the supplied name and no parameters.
static Method
findMethod ( Class <?> clazz, String name, Class <?>... paramTypes)
Attempt to find a Method on the supplied class with the supplied name and parameter types.
static Method []
getAllDeclaredMethods ( Class <?> leafClass)
Get all declared methods on the leaf class and all superclasses.
static Method []
Variant of Class.getDeclaredMethods() that uses a local cache in order to avoid new Method instances.
static Object
Get the field represented by the supplied field object on the specified target object .
static Method []
Get the unique set of declared methods on the leaf class and all superclasses.
static Method []
Get the unique set of declared methods on the leaf class and all superclasses.
static void
Handle the given invocation target exception.
static void
Handle the given reflection exception.
static Object
Invoke the specified Method against the supplied target object with no arguments.
static Object
invokeMethod ( Method method, Object target, Object ... args)
Invoke the specified Method against the supplied target object with the supplied arguments.
static boolean
Determine whether the given method is a CGLIB 'renamed' method, following the pattern "CGLIB$methodName$0".
static boolean
Determine whether the given method is an "equals" method.
static boolean
Determine whether the given method is a "hashCode" method.
static boolean
Determine whether the given method is originally declared by Object .
static boolean
Determine whether the given field is a "public static final" constant.
static boolean
Determine whether the given method is a "toString" method.
static void
Make the given constructor accessible, explicitly setting it accessible if necessary.
static void
Make the given field accessible, explicitly setting it accessible if necessary.
static void
Make the given method accessible, explicitly setting it accessible if necessary.
static void
Rethrow the given exception , which is presumably the target exception of an InvocationTargetException .
static void
Rethrow the given exception , which is presumably the target exception of an InvocationTargetException .
static void
Set the field represented by the supplied field object on the specified target object to the specified value .
static void
Given the source object and the destination, which must be the same class or a subclass, copy all fields, including inherited fields.

USER_DECLARED_METHODS

public static final ReflectionUtils.MethodFilter USER_DECLARED_METHODS
Pre-built ReflectionUtils.MethodFilter that matches all non-bridge non-synthetic methods which are not declared on java.lang.Object .
Since:
3.0.5

handleReflectionException

public static void handleReflectionException ( Exception ex)
Handle the given reflection exception.

Should only be called if no checked exception is expected to be thrown by a target method, or if an error occurs while accessing a method or field.

Throws the underlying RuntimeException or Error in case of an InvocationTargetException with such a root cause. Throws an IllegalStateException with an appropriate message or UndeclaredThrowableException otherwise.

Parameters:
ex - the reflection exception to handle

handleInvocationTargetException

public static void handleInvocationTargetException ( InvocationTargetException ex)
Handle the given invocation target exception. Should only be called if no checked exception is expected to be thrown by the target method.

Throws the underlying RuntimeException or Error in case of such a root cause. Throws an UndeclaredThrowableException otherwise.

Parameters:
ex - the invocation target exception to handle

rethrowRuntimeException

public static void rethrowRuntimeException ( Throwable ex)
Rethrow the given exception , which is presumably the target exception of an InvocationTargetException . Should only be called if no checked exception is expected to be thrown by the target method.

Rethrows the underlying exception cast to a RuntimeException or Error if appropriate; otherwise, throws an UndeclaredThrowableException .

Parameters:
ex - the exception to rethrow
Throws:
RuntimeException - the rethrown exception

rethrowException

public static void rethrowException ( Throwable throwable) throws Exception
Rethrow the given exception , which is presumably the target exception of an InvocationTargetException . Should only be called if no checked exception is expected to be thrown by the target method.

Rethrows the underlying exception cast to an Exception or Error if appropriate; otherwise, throws an UndeclaredThrowableException .

Parameters:
throwable - the exception to rethrow
Throws:
Exception - the rethrown exception (in case of a checked exception)

accessibleConstructor

public static <T> Constructor <T> accessibleConstructor ( Class <T> clazz, Class <?>... parameterTypes) throws NoSuchMethodException
Obtain an accessible constructor for the given class and parameters.
Parameters:
clazz - the clazz to check
parameterTypes - the parameter types of the desired constructor
Returns:
the constructor reference
Throws:
NoSuchMethodException - if no such constructor exists
Since:

makeAccessible

public static void makeAccessible ( Constructor <?> ctor)
Make the given constructor accessible, explicitly setting it accessible if necessary. The setAccessible(true) method is only called when actually necessary, to avoid unnecessary conflicts.
Parameters:
ctor - the constructor to make accessible
See Also:
  • Constructor.setAccessible(boolean)
  • public static Method findMethod ( Class <?> clazz, String name)
    Attempt to find a Method on the supplied class with the supplied name and no parameters. Searches all superclasses up to Object .

    Returns null if no Method can be found.

    Parameters:
    clazz - the class to introspect
    name - the name of the method
    Returns:
    the Method object, or null if none found
    @Nullable Class <?>... paramTypes)
    Attempt to find a Method on the supplied class with the supplied name and parameter types. Searches all superclasses up to Object .

    Returns null if no Method can be found.

    Parameters:
    clazz - the class to introspect
    name - the name of the method
    paramTypes - the parameter types of the method (may be null to indicate any signature)
    Returns:
    the Method object, or null if none found
    @Nullable Object target)
    Invoke the specified Method against the supplied target object with no arguments. The target object can be null when invoking a static Method .

    Thrown exceptions are handled via a call to handleReflectionException(java.lang.Exception) .

    Parameters:
    method - the method to invoke
    target - the target object to invoke the method on
    Returns:
    the invocation result, if any
    See Also:
  • invokeMethod(java.lang.reflect.Method, Object, Object[])
  • @Nullable Object ... args)
    Invoke the specified Method against the supplied target object with the supplied arguments. The target object can be null when invoking a static Method .

    Thrown exceptions are handled via a call to handleReflectionException(java.lang.Exception) .

    Parameters:
    method - the method to invoke
    target - the target object to invoke the method on
    args - the invocation arguments (may be null )
    Returns:
    the invocation result, if any

    declaresException

    public static boolean declaresException ( Method method, Class <?> exceptionType)
    Determine whether the given method explicitly declares the given exception or one of its superclasses, which means that an exception of that type can be propagated as-is within a reflective invocation.
    Parameters:
    method - the declaring method
    exceptionType - the exception to throw
    Returns:
    true if the exception can be thrown as-is; false if it needs to be wrapped

    doWithLocalMethods

    public static void doWithLocalMethods ( Class <?> clazz, ReflectionUtils.MethodCallback mc)
    Perform the given callback operation on all matching methods of the given class, as locally declared or equivalent thereof (such as default methods on Java 8 based interfaces that the given class implements).
    Parameters:
    clazz - the class to introspect
    mc - the callback to invoke for each method
    Throws:
    IllegalStateException - if introspection fails
    Since:
    See Also:
  • doWithMethods(java.lang.Class<?>, org.springframework.util.ReflectionUtils.MethodCallback)
  • doWithMethods

    public static void doWithMethods ( Class <?> clazz, ReflectionUtils.MethodCallback mc)
    Perform the given callback operation on all matching methods of the given class and superclasses.

    The same named method occurring on subclass and superclass will appear twice, unless excluded by a ReflectionUtils.MethodFilter .

    Parameters:
    clazz - the class to introspect
    mc - the callback to invoke for each method
    Throws:
    IllegalStateException - if introspection fails
    See Also:
  • doWithMethods(Class, MethodCallback, MethodFilter)
  • doWithMethods

    Perform the given callback operation on all matching methods of the given class and superclasses (or given interface and super-interfaces).

    The same named method occurring on subclass and superclass will appear twice, unless excluded by the specified ReflectionUtils.MethodFilter .

    Parameters:
    clazz - the class to introspect
    mc - the callback to invoke for each method
    mf - the filter that determines the methods to apply the callback to
    Throws:
    IllegalStateException - if introspection fails

    getAllDeclaredMethods

    public static Method [] getAllDeclaredMethods ( Class <?> leafClass)
    Get all declared methods on the leaf class and all superclasses. Leaf class methods are included first.
    Parameters:
    leafClass - the class to introspect
    Throws:
    IllegalStateException - if introspection fails

    getUniqueDeclaredMethods

    public static Method [] getUniqueDeclaredMethods ( Class <?> leafClass)
    Get the unique set of declared methods on the leaf class and all superclasses. Leaf class methods are included first and while traversing the superclass hierarchy any methods found with signatures matching a method already included are filtered out.
    Parameters:
    leafClass - the class to introspect
    Throws:
    IllegalStateException - if introspection fails

    getUniqueDeclaredMethods

    public static Method [] getUniqueDeclaredMethods ( Class <?> leafClass, @Nullable ReflectionUtils.MethodFilter mf)
    Get the unique set of declared methods on the leaf class and all superclasses. Leaf class methods are included first and while traversing the superclass hierarchy any methods found with signatures matching a method already included are filtered out.
    Parameters:
    leafClass - the class to introspect
    mf - the filter that determines the methods to take into account
    Throws:
    IllegalStateException - if introspection fails
    Since:

    getDeclaredMethods

    public static Method [] getDeclaredMethods ( Class <?> clazz)
    Variant of Class.getDeclaredMethods() that uses a local cache in order to avoid new Method instances. In addition, it also includes Java 8 default methods from locally implemented interfaces, since those are effectively to be treated just like declared methods.
    Parameters:
    clazz - the class to introspect
    Returns:
    the cached array of methods
    Throws:
    IllegalStateException - if introspection fails
    Since:
    See Also:
  • Class.getDeclaredMethods()
  • public static boolean isEqualsMethod ( @Nullable Method method)
    Determine whether the given method is an "equals" method.
    See Also:
  • Object.equals(Object)
  • public static boolean isHashCodeMethod ( @Nullable Method method)
    Determine whether the given method is a "hashCode" method.
    See Also:
  • Object.hashCode()
  • public static boolean isToStringMethod ( @Nullable Method method)
    Determine whether the given method is a "toString" method.
    See Also:
  • Object.toString()
  • isCglibRenamedMethod

    public static boolean isCglibRenamedMethod ( Method renamedMethod)
    Determine whether the given method is a CGLIB 'renamed' method, following the pattern "CGLIB$methodName$0".
    Parameters:
    renamedMethod - the method to check

    makeAccessible

    public static void makeAccessible ( Method method)
    Make the given method accessible, explicitly setting it accessible if necessary. The setAccessible(true) method is only called when actually necessary, to avoid unnecessary conflicts.
    Parameters:
    method - the method to make accessible
    See Also:
  • Method.setAccessible(boolean)
  • public static Field findField ( Class <?> clazz, String name)
    Attempt to find a field on the supplied Class with the supplied name . Searches all superclasses up to Object .
    Parameters:
    clazz - the class to introspect
    name - the name of the field
    Returns:
    the corresponding Field object, or null if not found
    Class <?> type)
    Attempt to find a field on the supplied Class with the supplied name and/or type . Searches all superclasses up to Object .
    Parameters:
    clazz - the class to introspect
    name - the name of the field (may be null if type is specified)
    type - the type of the field (may be null if name is specified)
    Returns:
    the corresponding Field object, or null if not found
    Object value)
    Set the field represented by the supplied field object on the specified target object to the specified value .

    In accordance with Field.set(Object, Object) semantics, the new value is automatically unwrapped if the underlying field has a primitive type.

    This method does not support setting static final fields.

    Thrown exceptions are handled via a call to handleReflectionException(Exception) .

    Parameters:
    field - the field to set
    target - the target object on which to set the field (or null for a static field)
    value - the value to set (may be null )
    Object target)
    Get the field represented by the supplied field object on the specified target object . In accordance with Field.get(Object) semantics, the returned value is automatically wrapped if the underlying field has a primitive type.

    Thrown exceptions are handled via a call to handleReflectionException(Exception) .

    Parameters:
    field - the field to get
    target - the target object from which to get the field (or null for a static field)
    Returns:
    the field's current value

    doWithLocalFields

    public static void doWithLocalFields ( Class <?> clazz, ReflectionUtils.FieldCallback fc)
    Invoke the given callback on all locally declared fields in the given class.
    Parameters:
    clazz - the target class to analyze
    fc - the callback to invoke for each field
    Throws:
    IllegalStateException - if introspection fails
    Since:
    See Also:
  • doWithFields(java.lang.Class<?>, org.springframework.util.ReflectionUtils.FieldCallback)
  • doWithFields

    public static void doWithFields ( Class <?> clazz, ReflectionUtils.FieldCallback fc)
    Invoke the given callback on all fields in the target class, going up the class hierarchy to get all declared fields.
    Parameters:
    clazz - the target class to analyze
    fc - the callback to invoke for each field
    Throws:
    IllegalStateException - if introspection fails

    doWithFields

    Invoke the given callback on all fields in the target class, going up the class hierarchy to get all declared fields.
    Parameters:
    clazz - the target class to analyze
    fc - the callback to invoke for each field
    ff - the filter that determines the fields to apply the callback to
    Throws:
    IllegalStateException - if introspection fails

    shallowCopyFieldState

    public static void shallowCopyFieldState ( Object src, Object dest)
    Given the source object and the destination, which must be the same class or a subclass, copy all fields, including inherited fields. Designed to work on objects with public no-arg constructors.
    Throws:
    IllegalStateException - if introspection fails

    isPublicStaticFinal

    public static boolean isPublicStaticFinal ( Field field)
    Determine whether the given field is a "public static final" constant.
    Parameters:
    field - the field to check

    makeAccessible

    public static void makeAccessible ( Field field)
    Make the given field accessible, explicitly setting it accessible if necessary. The setAccessible(true) method is only called when actually necessary, to avoid unnecessary conflicts.
    Parameters:
    field - the field to make accessible
    See Also:
  • Field.setAccessible(boolean)
  •