MethodUtils (Apache Commons BeanUtils 1.9.2 API)

java.lang.Object
- org.apache.commons.beanutils.MethodUtils

```
public class MethodUtils
extends Object
```
Utility reflection methods focused on methods in general rather than properties in particular.

Known Limitations

Accessing Public Methods In A Default Access Superclass

There is an issue when invoking public methods contained in a default access superclass. 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 setAccessible 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 privilages. If this call fails then a warning will be logged and the method may fail.

Version:

$Id: MethodUtils.java 1540186 2013-11-08 21:08:30Z oheger $

Constructor Summary

Constructors
Constructor and Description

MethodUtils()

Constructors
Constructor and Description
`MethodUtils()`

Method Summary

Methods
Modifier and Type	Method and Description
`static int`	`clearCache()` Clear the method cache.
`static Method`	`getAccessibleMethod(Class<?> clazz, Method method)` Return an accessible method (that is, one that can be invoked via reflection) that implements the specified Method.
`static Method`	`getAccessibleMethod(Class<?> clazz, String methodName, Class<?> parameterType)` Return an accessible method (that is, one that can be invoked via reflection) with given name and a single parameter.
`static Method`	`getAccessibleMethod(Class<?> clazz, String methodName, Class<?>[] parameterTypes)` Return an accessible method (that is, one that can be invoked via reflection) with given name and parameters.
`static Method`	`getAccessibleMethod(Method method)` Return an accessible method (that is, one that can be invoked via reflection) that implements the specified Method.
`static Method`	`getMatchingAccessibleMethod(Class<?> clazz, String methodName, Class<?>[] parameterTypes)` Find an accessible method that matches the given name and has compatible parameters.
`static Class<?>`	`getPrimitiveType(Class<?> wrapperType)` Gets the class for the primitive type corresponding to the primitive wrapper class given.
`static Class<?>`	`getPrimitiveWrapper(Class<?> primitiveType)` Gets the wrapper object class for the given primitive type class.
`static Object`	`invokeExactMethod(Object object, String methodName, Object arg)` Invoke a method whose parameter type matches exactly the object type.
`static Object`	`invokeExactMethod(Object object, String methodName, Object[] args)` Invoke a method whose parameter types match exactly the object types.
`static Object`	`invokeExactMethod(Object object, String methodName, Object[] args, Class<?>[] parameterTypes)` Invoke a method whose parameter types match exactly the parameter types given.
`static Object`	`invokeExactStaticMethod(Class<?> objectClass, String methodName, Object arg)` Invoke a static method whose parameter type matches exactly the object type.
`static Object`	`invokeExactStaticMethod(Class<?> objectClass, String methodName, Object[] args)` Invoke a static method whose parameter types match exactly the object types.
`static Object`	`invokeExactStaticMethod(Class<?> objectClass, String methodName, Object[] args, Class<?>[] parameterTypes)` Invoke a static method whose parameter types match exactly the parameter types given.
`static Object`	`invokeMethod(Object object, String methodName, Object arg)` Invoke a named method whose parameter type matches the object type.
`static Object`	`invokeMethod(Object object, String methodName, Object[] args)` Invoke a named method whose parameter type matches the object type.
`static Object`	`invokeMethod(Object object, String methodName, Object[] args, Class<?>[] parameterTypes)` Invoke a named method whose parameter type matches the object type.
`static Object`	`invokeStaticMethod(Class<?> objectClass, String methodName, Object arg)` Invoke a named static method whose parameter type matches the object type.
`static Object`	`invokeStaticMethod(Class<?> objectClass, String methodName, Object[] args)` Invoke a named static method whose parameter type matches the object type.
`static Object`	`invokeStaticMethod(Class<?> objectClass, String methodName, Object[] args, Class<?>[] parameterTypes)` Invoke a named static method whose parameter type matches the object type.
`static boolean`	`isAssignmentCompatible(Class<?> parameterType, Class<?> parameterization)` Determine whether a type can be used as a parameter in a method invocation.
`static void`	`setCacheMethods(boolean cacheMethods)` Set whether methods should be cached for greater performance or not, default is `true`.
`static Class<?>`	`toNonPrimitiveClass(Class<?> clazz)` Find a non primitive representation for given primitive class.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - MethodUtils
```
public MethodUtils()
```
- Method Detail
  - setCacheMethods
```
public static void setCacheMethods(boolean cacheMethods)
```
    Set whether methods should be cached for greater performance or not, default is true.
    
    Parameters:
    cacheMethods - true if methods should be cached for greater performance, otherwise false
    Since:
    
    1.8.0
  - clearCache
```
public static int clearCache()
```
    Clear the method cache.
    
    Returns:
    the number of cached methods cleared
    Since:
    
    1.8.0
  - invokeMethod
```
public static Object invokeMethod(Object object,
                  String methodName,
                  Object arg)
                           throws NoSuchMethodException,
                                  IllegalAccessException,
                                  InvocationTargetException
```
    Invoke a named method whose parameter type matches the object type.
    
    The behaviour of this method is less deterministic than invokeExactMethod(). It loops through all methods with names that match and then executes the first it finds with compatible parameters.
    
    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 invokeMethod(Object object,String methodName,Object [] args).
    
    Parameters:
    object - invoke method on this object
    methodName - get method with this name
    arg - use this argument. May be null (this will result in calling the parameterless method with name methodName).
    
    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,
                  String methodName,
                  Object[] args)
                           throws NoSuchMethodException,
                                  IllegalAccessException,
                                  InvocationTargetException
```
    Invoke a named method whose parameter type matches the object type.
    
    The behaviour of this method is less deterministic than invokeExactMethod(Object object,String methodName,Object [] args). It loops through all methods with names that match and then executes the first it finds with compatible parameters.
    
    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 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 (passing null will result in calling the parameterless method with name methodName).
    
    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,
                  String methodName,
                  Object[] args,
                  Class<?>[] parameterTypes)
                           throws NoSuchMethodException,
                                  IllegalAccessException,
                                  InvocationTargetException
```
    Invoke a named method whose parameter type matches the object type.
    
    The behaviour of this method is less deterministic than invokeExactMethod(Object object,String methodName,Object [] args,Class[] parameterTypes). It loops through all methods with names that match and then executes the first it finds with compatible parameters.
    
    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:
    object - invoke method on this object
    methodName - get method with this name
    args - use these arguments - treat null as empty array (passing null will result in calling the parameterless method with name methodName).
    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,
                       Object arg)
                                throws NoSuchMethodException,
                                       IllegalAccessException,
                                       InvocationTargetException
```
    Invoke a method whose parameter type matches exactly the object type.
    
    This is a convenient wrapper for invokeExactMethod(Object object,String methodName,Object [] args).
    
    Parameters:
    object - invoke method on this object
    methodName - get method with this name
    arg - use this argument. May be null (this will result in calling the parameterless method with name methodName).
    
    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)
                                throws NoSuchMethodException,
                                       IllegalAccessException,
                                       InvocationTargetException
```
    Invoke a method whose parameter types match exactly the object types.
    
    This uses reflection to invoke the method obtained from a call to getAccessibleMethod().
    
    Parameters:
    object - invoke method on this object
    methodName - get method with this name
    args - use these arguments - treat null as empty array (passing null will result in calling the parameterless method with name methodName).
    
    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
```
    Invoke a method whose parameter types match exactly the parameter types given.
    
    This uses reflection to invoke the method obtained from a call to getAccessibleMethod().
    
    Parameters:
    object - invoke method on this object
    methodName - get method with this name
    args - use these arguments - treat null as empty array (passing null will result in calling the parameterless method with name methodName).
    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<?> objectClass,
                             String methodName,
                             Object[] args,
                             Class<?>[] parameterTypes)
                                      throws NoSuchMethodException,
                                             IllegalAccessException,
                                             InvocationTargetException
```
    Invoke 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:
    objectClass - invoke static method on this class
    methodName - get method with this name
    args - use these arguments - treat null as empty array (passing null will result in calling the parameterless method with name methodName).
    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:
    
    1.8.0
  - invokeStaticMethod
```
public static Object invokeStaticMethod(Class<?> objectClass,
                        String methodName,
                        Object arg)
                                 throws NoSuchMethodException,
                                        IllegalAccessException,
                                        InvocationTargetException
```
    Invoke a named static method whose parameter type matches the object type.
    
    The behaviour of this method is less deterministic than invokeExactMethod(Object, String, Object[], Class[]). It loops through all methods with names that match and then executes the first it finds with compatible parameters.
    
    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 objectClass,String methodName,Object [] args).
    
    Parameters:
    objectClass - invoke static method on this class
    methodName - get method with this name
    arg - use this argument. May be null (this will result in calling the parameterless method with name methodName).
    
    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:
    
    1.8.0
  - invokeStaticMethod
```
public static Object invokeStaticMethod(Class<?> objectClass,
                        String methodName,
                        Object[] args)
                                 throws NoSuchMethodException,
                                        IllegalAccessException,
                                        InvocationTargetException
```
    Invoke a named static method whose parameter type matches the object type.
    
    The behaviour of this method is less deterministic than invokeExactMethod(Object object,String methodName,Object [] args). It loops through all methods with names that match and then executes the first it finds with compatible parameters.
    
    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 objectClass,String methodName,Object [] args,Class[] parameterTypes).
    
    Parameters:
    objectClass - invoke static method on this class
    methodName - get method with this name
    args - use these arguments - treat null as empty array (passing null will result in calling the parameterless method with name methodName).
    
    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:
    
    1.8.0
  - invokeStaticMethod
```
public static Object invokeStaticMethod(Class<?> objectClass,
                        String methodName,
                        Object[] args,
                        Class<?>[] parameterTypes)
                                 throws NoSuchMethodException,
                                        IllegalAccessException,
                                        InvocationTargetException
```
    Invoke a named static method whose parameter type matches the object type.
    
    The behaviour of this method is less deterministic than invokeExactStaticMethod(Class objectClass,String methodName,Object [] args,Class[] parameterTypes). It loops through all methods with names that match and then executes the first it finds with compatible parameters.
    
    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:
    objectClass - invoke static method on this class
    methodName - get method with this name
    args - use these arguments - treat null as empty array (passing null will result in calling the parameterless method with name methodName).
    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:
    
    1.8.0
  - invokeExactStaticMethod
```
public static Object invokeExactStaticMethod(Class<?> objectClass,
                             String methodName,
                             Object arg)
                                      throws NoSuchMethodException,
                                             IllegalAccessException,
                                             InvocationTargetException
```
    Invoke a static method whose parameter type matches exactly the object type.
    
    This is a convenient wrapper for invokeExactStaticMethod(Class objectClass,String methodName,Object [] args).
    
    Parameters:
    objectClass - invoke static method on this class
    methodName - get method with this name
    arg - use this argument. May be null (this will result in calling the parameterless method with name methodName).
    
    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:
    
    1.8.0
  - invokeExactStaticMethod
```
public static Object invokeExactStaticMethod(Class<?> objectClass,
                             String methodName,
                             Object[] args)
                                      throws NoSuchMethodException,
                                             IllegalAccessException,
                                             InvocationTargetException
```
    Invoke 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:
    objectClass - invoke static method on this class
    methodName - get method with this name
    args - use these arguments - treat null as empty array (passing null will result in calling the parameterless method with name methodName).
    
    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:
    
    1.8.0
  - getAccessibleMethod
```
public static Method getAccessibleMethod(Class<?> clazz,
                         String methodName,
                         Class<?> parameterType)
```
    Return an accessible method (that is, one that can be invoked via reflection) with given name and a single parameter. If no such method can be found, return null. Basically, a convenience wrapper that constructs a Class array for you.
    
    Parameters:
    clazz - get method from this class
    methodName - get method with this name
    parameterType - taking this type of parameter
    
    Returns:
    The accessible method
  - getAccessibleMethod
```
public static Method getAccessibleMethod(Class<?> clazz,
                         String methodName,
                         Class<?>[] parameterTypes)
```
    Return 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 convenient wrapper for getAccessibleMethod(Method method).
    
    Parameters:
    clazz - 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)
```
    Return 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
  - getAccessibleMethod
```
public static Method getAccessibleMethod(Class<?> clazz,
                         Method method)
```
    Return 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:
    clazz - The class of the object
    method - The method that we wish to call
    
    Returns:
    The accessible method
    Since:
    
    1.8.0
  - getMatchingAccessibleMethod
```
public static Method getMatchingAccessibleMethod(Class<?> clazz,
                                 String methodName,
                                 Class<?>[] parameterTypes)
```
    Find 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 slightly undeterministic since it loops through methods names and return the first matching method.
    
    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:
    clazz - find method in this class
    methodName - find method with this name
    parameterTypes - find method with compatible parameters
    
    Returns:
    The accessible method
  - isAssignmentCompatible
```
public static final boolean isAssignmentCompatible(Class<?> parameterType,
                             Class<?> parameterization)
```
    Determine whether a type can be used as a parameter in a method invocation. This method handles primitive conversions correctly.
    
    In order words, it will match a Boolean to a boolean, a Long to a long, a Float to a float, a Integer to a int, and a Double to a double. Now logic widening matches are allowed. For example, a Long will not match a int.
    
    Parameters:
    parameterType - the type of parameter accepted by the method
    parameterization - the type of parameter being tested
    
    Returns:
    true if the assignment is compatible.
  - getPrimitiveWrapper
```
public static Class<?> getPrimitiveWrapper(Class<?> primitiveType)
```
    Gets the wrapper object class for the given primitive type class. For example, passing boolean.class returns Boolean.class
    
    Parameters:
    primitiveType - the primitive type class for which a match is to be found
    
    Returns:
    the wrapper type associated with the given primitive or null if no match is found
  - getPrimitiveType
```
public static Class<?> getPrimitiveType(Class<?> wrapperType)
```
    Gets the class for the primitive type corresponding to the primitive wrapper class given. For example, an instance of Boolean.class returns a boolean.class.
    
    Parameters:
    wrapperType - the
    
    Returns:
    the primitive type class corresponding to the given wrapper class, null if no match is found
  - toNonPrimitiveClass
```
public static Class<?> toNonPrimitiveClass(Class<?> clazz)
```
    Find a non primitive representation for given primitive class.
    
    Parameters:
    clazz - the class to find a representation for, not null
    
    Returns:
    the original class if it not a primitive. Otherwise the wrapper class. Not null

Class MethodUtils

Known Limitations

Accessing Public Methods In A Default Access Superclass

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

MethodUtils

Method Detail

setCacheMethods

clearCache

invokeMethod

invokeMethod

invokeMethod

invokeExactMethod

invokeExactMethod

invokeExactMethod

invokeExactStaticMethod

invokeStaticMethod

invokeStaticMethod

invokeStaticMethod

invokeExactStaticMethod

invokeExactStaticMethod

getAccessibleMethod

getAccessibleMethod

getAccessibleMethod

getAccessibleMethod

getMatchingAccessibleMethod

isAssignmentCompatible

getPrimitiveWrapper

getPrimitiveType

toNonPrimitiveClass