Package io.lettuce.core.dynamic.support

Class ReflectionUtils

java.lang.Object

io.lettuce.core.dynamic.support.ReflectionUtils

public abstract class ReflectionUtils
extends Object

Simple utility class for working with the reflection API and handling reflection exceptions.

Only intended for internal use.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	ReflectionUtils.FieldCallback	Callback interface invoked on each field in the hierarchy.
static interface	ReflectionUtils.FieldFilter	Callback optionally used to filter fields to be operated on by a field callback.
static interface	ReflectionUtils.MethodCallback	Action to take on each method.
static interface	ReflectionUtils.MethodFilter	Callback optionally used to filter methods to be operated on by a method callback.

Constructor Summary

Constructors

Constructor	Description
ReflectionUtils()

Method Summary

Modifier and Type	Method	Description
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.
static void	doWithFields(Class<?> clazz, ReflectionUtils.FieldCallback fc, ReflectionUtils.FieldFilter ff)	Invoke the given callback on all fields in the target class, going up the class hierarchy to get all declared fields.
static void	doWithMethods(Class<?> clazz, ReflectionUtils.MethodCallback mc)	Perform the given callback operation on all matching methods of the given class and superclasses.
static void	doWithMethods(Class<?> clazz, ReflectionUtils.MethodCallback mc, ReflectionUtils.MethodFilter mf)	Perform the given callback operation on all matching methods of the given class and superclasses (or given interface and super-interfaces).
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 Object	getField(Field field, Object target)	Get the field represented by the supplied field object on the specified target object.
static void	handleInvocationTargetException(InvocationTargetException ex)	Handle the given invocation target exception.
static void	handleReflectionException(Exception ex)	Handle the given reflection exception.
static Object	invokeMethod(Method method, Object target)	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 void	rethrowRuntimeException(Throwable ex)	Rethrow the given exception, which is presumably the target exception of an InvocationTargetException.

Methods inherited from class java.lang.Object

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

Constructor Detail

ReflectionUtils

public ReflectionUtils()

Method Detail

getField

public static Object getField(Field field,
                              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

Returns:

the field's current value

findMethod

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

findMethod

public 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. 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

invokeMethod

public static Object invokeMethod(Method method,
                                  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[])

invokeMethod

public static Object invokeMethod(Method method,
                                  Object target,
                                  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

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 the target method.

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

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

See Also:

doWithMethods(Class, MethodCallback, MethodFilter)

doWithMethods

public static void doWithMethods(Class<?> clazz,
                                 ReflectionUtils.MethodCallback mc,
                                 ReflectionUtils.MethodFilter mf)

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

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

doWithFields

public static void doWithFields(Class<?> clazz,
                                ReflectionUtils.FieldCallback fc,
                                ReflectionUtils.FieldFilter ff)

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