org.apache.commons.lang3.reflect

Class MethodUtils

java.lang.Object

org.apache.commons.lang3.reflect.MethodUtils

public class MethodUtils
extends Object

Utility reflection methods focused on Methods, originally from Commons BeanUtils. Differences from the BeanUtils version may be noted, especially where similar functionality already existed within Lang.

Known Limitations

Accessing Public Methods In A Default Access Superclass

There is an issue when invoking public methods contained in a default access superclass on JREs prior to 1.4. Reflection locates these methods fine and correctly assigns them as public. However, an IllegalAccessException is thrown if the method is invoked.

MethodUtils contains a workaround for this situation. It will attempt to call AccessibleObject.setAccessible(boolean) on this method. If this call succeeds, then the method can be invoked as normal. This call will only succeed when the application has sufficient security privileges. If this call fails then the method may fail.

Since:

2.5

Constructor Summary

Constructors

Constructor and Description
MethodUtils() MethodUtils instances should NOT be constructed in standard programming.

Method Summary

Modifier and Type	Method and Description
static Method	getAccessibleMethod(Class<?> cls, String methodName, Class<?>... parameterTypes) Returns an accessible method (that is, one that can be invoked via reflection) with given name and parameters.
static Method	getAccessibleMethod(Method method) Returns an accessible method (that is, one that can be invoked via reflection) that implements the specified Method.
static <A extends Annotation> A	getAnnotation(Method method, Class<A> annotationCls, boolean searchSupers, boolean ignoreAccess) Gets the annotation object with the given annotation type that is present on the given method or optionally on any equivalent method in super classes and interfaces.
static Method	getMatchingAccessibleMethod(Class<?> cls, String methodName, Class<?>... parameterTypes) Finds an accessible method that matches the given name and has compatible parameters.
static Method	getMatchingMethod(Class<?> cls, String methodName, Class<?>... parameterTypes) Retrieves a method whether or not it's accessible.
static List<Method>	getMethodsListWithAnnotation(Class<?> cls, Class<? extends Annotation> annotationCls) Gets all class level public methods of the given class that are annotated with the given annotation.
static List<Method>	getMethodsListWithAnnotation(Class<?> cls, Class<? extends Annotation> annotationCls, boolean searchSupers, boolean ignoreAccess) Gets all methods of the given class that are annotated with the given annotation.
static Method[]	getMethodsWithAnnotation(Class<?> cls, Class<? extends Annotation> annotationCls) Gets all class level public methods of the given class that are annotated with the given annotation.
static Method[]	getMethodsWithAnnotation(Class<?> cls, Class<? extends Annotation> annotationCls, boolean searchSupers, boolean ignoreAccess) Gets all methods of the given class that are annotated with the given annotation.
static Set<Method>	getOverrideHierarchy(Method method, ClassUtils.Interfaces interfacesBehavior) Gets the hierarchy of overridden methods down to result respecting generics.
static Object	invokeExactMethod(Object object, String methodName) Invokes a method whose parameter types match exactly the object types.
static Object	invokeExactMethod(Object object, String methodName, Object... args) Invokes a method with no parameters.
static Object	invokeExactMethod(Object object, String methodName, Object[] args, Class<?>[] parameterTypes) Invokes a method whose parameter types match exactly the parameter types given.
static Object	invokeExactStaticMethod(Class<?> cls, String methodName, Object... args) Invokes a static method whose parameter types match exactly the object types.
static Object	invokeExactStaticMethod(Class<?> cls, String methodName, Object[] args, Class<?>[] parameterTypes) Invokes a static method whose parameter types match exactly the parameter types given.
static Object	invokeMethod(Object object, boolean forceAccess, String methodName) Invokes a named method without parameters.
static Object	invokeMethod(Object object, boolean forceAccess, String methodName, Object... args) Invokes a named method whose parameter type matches the object type.
static Object	invokeMethod(Object object, boolean forceAccess, String methodName, Object[] args, Class<?>[] parameterTypes) Invokes a named method whose parameter type matches the object type.
static Object	invokeMethod(Object object, String methodName) Invokes a named method without parameters.
static Object	invokeMethod(Object object, String methodName, Object... args) Invokes a named method whose parameter type matches the object type.
static Object	invokeMethod(Object object, String methodName, Object[] args, Class<?>[] parameterTypes) Invokes a named method whose parameter type matches the object type.
static Object	invokeStaticMethod(Class<?> cls, String methodName, Object... args) Invokes a named static method whose parameter type matches the object type.
static Object	invokeStaticMethod(Class<?> cls, String methodName, Object[] args, Class<?>[] parameterTypes) Invokes a named static method whose parameter type matches the object type.

Methods inherited from class java.lang.Object

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

Constructor Detail

MethodUtils

public MethodUtils()

MethodUtils instances should NOT be constructed in standard programming. Instead, the class should be used as MethodUtils.getAccessibleMethod(method).

This constructor is public to permit tools that require a JavaBean instance to operate.

Method Detail

invokeMethod

public static Object invokeMethod(Object object,
                                  String methodName)
                           throws NoSuchMethodException,
                                  IllegalAccessException,
                                  InvocationTargetException

Invokes a named method without parameters.

This method delegates the method search to getMatchingAccessibleMethod(Class, String, Class[]).

This is a convenient wrapper for invokeMethod(Object object, String methodName, Object[] args, Class[] parameterTypes).

Parameters:

object - invoke method on this object

methodName - get method with this name

Returns:

The value returned by the invoked method

Throws:

NoSuchMethodException - if there is no such accessible method

InvocationTargetException - wraps an exception thrown by the method invoked

IllegalAccessException - if the requested method is not accessible via reflection

Since:

3.4

invokeMethod

public static Object invokeMethod(Object object,
                                  boolean forceAccess,
                                  String methodName)
                           throws NoSuchMethodException,
                                  IllegalAccessException,
                                  InvocationTargetException

Invokes a named method without parameters.

This is a convenient wrapper for invokeMethod(Object object, boolean forceAccess, String methodName, Object[] args, Class[] parameterTypes).

Parameters:

object - invoke method on this object

forceAccess - force access to invoke method even if it's not accessible

methodName - get method with this name

Returns:

The value returned by the invoked method

Throws:

NoSuchMethodException - if there is no such accessible method

InvocationTargetException - wraps an exception thrown by the method invoked

IllegalAccessException - if the requested method is not accessible via reflection

Since:

3.5

invokeMethod

public static Object invokeMethod(Object object,
                                  String methodName,
                                  Object... args)
                           throws NoSuchMethodException,
                                  IllegalAccessException,
                                  InvocationTargetException

Invokes a named method whose parameter type matches the object type.

This method delegates the method search to getMatchingAccessibleMethod(Class, String, Class[]).

This method supports calls to methods taking primitive parameters via passing in wrapping classes. So, for example, a Boolean object would match a boolean primitive.

This is a convenient wrapper for invokeMethod(Object object, String methodName, Object[] args, Class[] parameterTypes).

Parameters:

object - invoke method on this object

methodName - get method with this name

args - use these arguments - treat null as empty array

Returns:

The value returned by the invoked method

Throws:

NoSuchMethodException - if there is no such accessible method

InvocationTargetException - wraps an exception thrown by the method invoked

IllegalAccessException - if the requested method is not accessible via reflection

invokeMethod

public static Object invokeMethod(Object object,
                                  boolean forceAccess,
                                  String methodName,
                                  Object... args)
                           throws NoSuchMethodException,
                                  IllegalAccessException,
                                  InvocationTargetException

Invokes a named method whose parameter type matches the object type.

This method supports calls to methods taking primitive parameters via passing in wrapping classes. So, for example, a Boolean object would match a boolean primitive.

This is a convenient wrapper for invokeMethod(Object object, boolean forceAccess, String methodName, Object[] args, Class[] parameterTypes).

Parameters:

object - invoke method on this object

forceAccess - force access to invoke method even if it's not accessible

methodName - get method with this name

args - use these arguments - treat null as empty array

Returns:

The value returned by the invoked method

Throws:

NoSuchMethodException - if there is no such accessible method

InvocationTargetException - wraps an exception thrown by the method invoked

IllegalAccessException - if the requested method is not accessible via reflection

Since:

3.5

invokeMethod

public static Object invokeMethod(Object object,
                                  boolean forceAccess,
                                  String methodName,
                                  Object[] args,
                                  Class<?>[] parameterTypes)
                           throws NoSuchMethodException,
                                  IllegalAccessException,
                                  InvocationTargetException

Invokes a named method whose parameter type matches the object type.

This method supports calls to methods taking primitive parameters via passing in wrapping classes. So, for example, a Boolean object would match a boolean primitive.

Parameters:

object - invoke method on this object

forceAccess - force access to invoke method even if it's not accessible

methodName - get method with this name

args - use these arguments - treat null as empty array

parameterTypes - match these parameters - treat null as empty array

Returns:

The value returned by the invoked method

Throws:

NoSuchMethodException - if there is no such accessible method

InvocationTargetException - wraps an exception thrown by the method invoked

IllegalAccessException - if the requested method is not accessible via reflection

Since:

3.5

invokeMethod

public static Object invokeMethod(Object object,
                                  String methodName,
                                  Object[] args,
                                  Class<?>[] parameterTypes)
                           throws NoSuchMethodException,
                                  IllegalAccessException,
                                  InvocationTargetException

Invokes a named method whose parameter type matches the object type.

This method delegates the method search to getMatchingAccessibleMethod(Class, String, Class[]).

This method supports calls to methods taking primitive parameters via passing in wrapping classes. So, for example, a Boolean object would match a boolean primitive.

Parameters:

object - invoke method on this object

methodName - get method with this name

args - use these arguments - treat null as empty array

parameterTypes - match these parameters - treat null as empty array

Returns:

The value returned by the invoked method

Throws:

NoSuchMethodException - if there is no such accessible method

InvocationTargetException - wraps an exception thrown by the method invoked

IllegalAccessException - if the requested method is not accessible via reflection

invokeExactMethod

public static Object invokeExactMethod(Object object,
                                       String methodName)
                                throws NoSuchMethodException,
                                       IllegalAccessException,
                                       InvocationTargetException

Invokes a method whose parameter types match exactly the object types.

This uses reflection to invoke the method obtained from a call to getAccessibleMethod(java.lang.Class<?>, java.lang.String, java.lang.Class<?>...)(Class, String, Class[])}.

Parameters:

object - invoke method on this object

methodName - get method with this name

Returns:

The value returned by the invoked method

Throws:

NoSuchMethodException - if there is no such accessible method

InvocationTargetException - wraps an exception thrown by the method invoked

IllegalAccessException - if the requested method is not accessible via reflection

Since:

3.4

invokeExactMethod

public static Object invokeExactMethod(Object object,
                                       String methodName,
                                       Object... args)
                                throws NoSuchMethodException,
                                       IllegalAccessException,
                                       InvocationTargetException

Invokes a method with no parameters.

This uses reflection to invoke the method obtained from a call to getAccessibleMethod(java.lang.Class<?>, java.lang.String, java.lang.Class<?>...)(Class, String, Class[])}.

Parameters:

object - invoke method on this object

methodName - get method with this name

args - use these arguments - treat null as empty array

Returns:

The value returned by the invoked method

Throws:

NoSuchMethodException - if there is no such accessible method

InvocationTargetException - wraps an exception thrown by the method invoked

IllegalAccessException - if the requested method is not accessible via reflection

invokeExactMethod

public static Object invokeExactMethod(Object object,
                                       String methodName,
                                       Object[] args,
                                       Class<?>[] parameterTypes)
                                throws NoSuchMethodException,
                                       IllegalAccessException,
                                       InvocationTargetException

Invokes a method whose parameter types match exactly the parameter types given.

This uses reflection to invoke the method obtained from a call to getAccessibleMethod(Class, String, Class[]).

Parameters:

object - invoke method on this object

methodName - get method with this name

args - use these arguments - treat null as empty array

parameterTypes - match these parameters - treat null as empty array

Returns:

The value returned by the invoked method

Throws:

NoSuchMethodException - if there is no such accessible method

InvocationTargetException - wraps an exception thrown by the method invoked

IllegalAccessException - if the requested method is not accessible via reflection

invokeExactStaticMethod

public static Object invokeExactStaticMethod(Class<?> cls,
                                             String methodName,
                                             Object[] args,
                                             Class<?>[] parameterTypes)
                                      throws NoSuchMethodException,
                                             IllegalAccessException,
                                             InvocationTargetException

Invokes a static method whose parameter types match exactly the parameter types given.

This uses reflection to invoke the method obtained from a call to getAccessibleMethod(Class, String, Class[]).

Parameters:

cls - invoke static method on this class

methodName - get method with this name

args - use these arguments - treat null as empty array

parameterTypes - match these parameters - treat null as empty array

Returns:

The value returned by the invoked method

Throws:

NoSuchMethodException - if there is no such accessible method

InvocationTargetException - wraps an exception thrown by the method invoked

IllegalAccessException - if the requested method is not accessible via reflection

invokeStaticMethod

public static Object invokeStaticMethod(Class<?> cls,
                                        String methodName,
                                        Object... args)
                                 throws NoSuchMethodException,
                                        IllegalAccessException,
                                        InvocationTargetException

Invokes a named static method whose parameter type matches the object type.

This method delegates the method search to getMatchingAccessibleMethod(Class, String, Class[]).

This method supports calls to methods taking primitive parameters via passing in wrapping classes. So, for example, a Boolean class would match a boolean primitive.

This is a convenient wrapper for invokeStaticMethod(Class, String, Object[], Class[]).

Parameters:

cls - invoke static method on this class

methodName - get method with this name

args - use these arguments - treat null as empty array

Returns:

The value returned by the invoked method

Throws:

NoSuchMethodException - if there is no such accessible method

InvocationTargetException - wraps an exception thrown by the method invoked

IllegalAccessException - if the requested method is not accessible via reflection

invokeStaticMethod

public static Object invokeStaticMethod(Class<?> cls,
                                        String methodName,
                                        Object[] args,
                                        Class<?>[] parameterTypes)
                                 throws NoSuchMethodException,
                                        IllegalAccessException,
                                        InvocationTargetException

Invokes a named static method whose parameter type matches the object type.

This method delegates the method search to getMatchingAccessibleMethod(Class, String, Class[]).

This method supports calls to methods taking primitive parameters via passing in wrapping classes. So, for example, a Boolean class would match a boolean primitive.

Parameters:

cls - invoke static method on this class

methodName - get method with this name

args - use these arguments - treat null as empty array

parameterTypes - match these parameters - treat null as empty array

Returns:

The value returned by the invoked method

Throws:

NoSuchMethodException - if there is no such accessible method

InvocationTargetException - wraps an exception thrown by the method invoked

IllegalAccessException - if the requested method is not accessible via reflection

invokeExactStaticMethod

public static Object invokeExactStaticMethod(Class<?> cls,
                                             String methodName,
                                             Object... args)
                                      throws NoSuchMethodException,
                                             IllegalAccessException,
                                             InvocationTargetException

Invokes a static method whose parameter types match exactly the object types.

This uses reflection to invoke the method obtained from a call to getAccessibleMethod(Class, String, Class[]).

Parameters:

cls - invoke static method on this class

methodName - get method with this name

args - use these arguments - treat null as empty array

Returns:

The value returned by the invoked method

Throws:

NoSuchMethodException - if there is no such accessible method

InvocationTargetException - wraps an exception thrown by the method invoked

IllegalAccessException - if the requested method is not accessible via reflection

getAccessibleMethod

public static Method getAccessibleMethod(Class<?> cls,
                                         String methodName,
                                         Class<?>... parameterTypes)

Returns an accessible method (that is, one that can be invoked via reflection) with given name and parameters. If no such method can be found, return null. This is just a convenience wrapper for getAccessibleMethod(Method).

Parameters:

cls - get method from this class

methodName - get method with this name

parameterTypes - with these parameters types

Returns:

The accessible method

getAccessibleMethod

public static Method getAccessibleMethod(Method method)

Returns an accessible method (that is, one that can be invoked via reflection) that implements the specified Method. If no such method can be found, return null.

Parameters:

method - The method that we wish to call

Returns:

The accessible method

getMatchingAccessibleMethod

public static Method getMatchingAccessibleMethod(Class<?> cls,
                                                 String methodName,
                                                 Class<?>... parameterTypes)

Finds an accessible method that matches the given name and has compatible parameters. Compatible parameters mean that every method parameter is assignable from the given parameters. In other words, it finds a method with the given name that will take the parameters given.

This method is used by invokeMethod(Object object, String methodName, Object[] args, Class[] parameterTypes).

This method can match primitive parameter by passing in wrapper classes. For example, a Boolean will match a primitive boolean parameter.

Parameters:

cls - find method in this class

methodName - find method with this name

parameterTypes - find method with most compatible parameters

Returns:

The accessible method

getMatchingMethod

public static Method getMatchingMethod(Class<?> cls,
                                       String methodName,
                                       Class<?>... parameterTypes)

Retrieves a method whether or not it's accessible. If no such method can be found, return null.

Parameters:

cls - The class that will be subjected to the method search

methodName - The method that we wish to call

parameterTypes - Argument class types

Returns:

The method

Since:

3.5

getOverrideHierarchy

public static Set<Method> getOverrideHierarchy(Method method,
                                               ClassUtils.Interfaces interfacesBehavior)

Gets the hierarchy of overridden methods down to result respecting generics.

Parameters:

method - lowest to consider

interfacesBehavior - whether to search interfaces, null implies false

Returns:

Set<Method> in ascending order from sub- to superclass

Throws:

NullPointerException - if the specified method is null

Since:

3.2

getMethodsWithAnnotation

public static Method[] getMethodsWithAnnotation(Class<?> cls,
                                                Class<? extends Annotation> annotationCls)

Gets all class level public methods of the given class that are annotated with the given annotation.

Parameters:

cls - the Class to query

annotationCls - the Annotation that must be present on a method to be matched

Returns:

an array of Methods (possibly empty).

Throws:

IllegalArgumentException - if the class or annotation are null

Since:

3.4

getMethodsListWithAnnotation

public static List<Method> getMethodsListWithAnnotation(Class<?> cls,
                                                        Class<? extends Annotation> annotationCls)

Gets all class level public methods of the given class that are annotated with the given annotation.

Parameters:

cls - the Class to query

annotationCls - the Annotation that must be present on a method to be matched

Returns:

a list of Methods (possibly empty).

Throws:

IllegalArgumentException - if the class or annotation are null

Since:

3.4

getMethodsWithAnnotation

public static Method[] getMethodsWithAnnotation(Class<?> cls,
                                                Class<? extends Annotation> annotationCls,
                                                boolean searchSupers,
                                                boolean ignoreAccess)

Gets all methods of the given class that are annotated with the given annotation.

Parameters:

cls - the Class to query

annotationCls - the Annotation that must be present on a method to be matched

searchSupers - determines if a lookup in the entire inheritance hierarchy of the given class should be performed

ignoreAccess - determines if non public methods should be considered

Returns:

an array of Methods (possibly empty).

Throws:

IllegalArgumentException - if the class or annotation are null

Since:

3.6

getMethodsListWithAnnotation

public static List<Method> getMethodsListWithAnnotation(Class<?> cls,
                                                        Class<? extends Annotation> annotationCls,
                                                        boolean searchSupers,
                                                        boolean ignoreAccess)

Gets all methods of the given class that are annotated with the given annotation.

Parameters:

cls - the Class to query

annotationCls - the Annotation that must be present on a method to be matched

searchSupers - determines if a lookup in the entire inheritance hierarchy of the given class should be performed

ignoreAccess - determines if non public methods should be considered

Returns:

a list of Methods (possibly empty).

Throws:

IllegalArgumentException - if the class or annotation are null

Since:

3.6

getAnnotation

public static <A extends Annotation> A getAnnotation(Method method,
                                                     Class<A> annotationCls,
                                                     boolean searchSupers,
                                                     boolean ignoreAccess)

Gets the annotation object with the given annotation type that is present on the given method or optionally on any equivalent method in super classes and interfaces. Returns null if the annotation type was not present.

Stops searching for an annotation once the first annotation of the specified type has been found. Additional annotations of the specified type will be silently ignored.

Type Parameters:

A - the annotation type

Parameters:

method - the Method to query

annotationCls - the Annotation to check if is present on the method

searchSupers - determines if a lookup in the entire inheritance hierarchy of the given class is performed if the annotation was not directly present

ignoreAccess - determines if underlying method has to be accessible

Returns:

the first matching annotation, or null if not found

Throws:

IllegalArgumentException - if the method or annotation are null

Since:

3.6