Class MethodUtils


  • public class MethodUtils
    extends java.lang.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:
    $Id$
    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description
      private static class  MethodUtils.MethodDescriptor
      Represents the key to looking up a Method by reflection.
    • Field Summary

      Fields 
      Modifier and Type Field Description
      private static java.util.Map<MethodUtils.MethodDescriptor,​java.lang.ref.Reference<java.lang.reflect.Method>> cache
      Stores a cache of MethodDescriptor -> Method in a WeakHashMap.
      private static boolean CACHE_METHODS
      Indicates whether methods should be cached for improved performance.
      private static java.lang.Class<?>[] EMPTY_CLASS_PARAMETERS
      An empty class array
      private static java.lang.Object[] EMPTY_OBJECT_ARRAY
      An empty object array
      private static boolean loggedAccessibleWarning
      Only log warning about accessibility work around once.
    • Constructor Summary

      Constructors 
      Constructor Description
      MethodUtils()  
    • Method Summary

      All Methods Static Methods Concrete Methods 
      Modifier and Type Method Description
      private static void cacheMethod​(MethodUtils.MethodDescriptor md, java.lang.reflect.Method method)
      Add a method to the cache.
      static int clearCache()
      Clear the method cache.
      static java.lang.reflect.Method getAccessibleMethod​(java.lang.Class<?> clazz, java.lang.reflect.Method method)
      Return an accessible method (that is, one that can be invoked via reflection) that implements the specified Method.
      static java.lang.reflect.Method getAccessibleMethod​(java.lang.Class<?> clazz, java.lang.String methodName, java.lang.Class<?> parameterType)
      Return an accessible method (that is, one that can be invoked via reflection) with given name and a single parameter.
      static java.lang.reflect.Method getAccessibleMethod​(java.lang.Class<?> clazz, java.lang.String methodName, java.lang.Class<?>[] parameterTypes)
      Return an accessible method (that is, one that can be invoked via reflection) with given name and parameters.
      static java.lang.reflect.Method getAccessibleMethod​(java.lang.reflect.Method method)
      Return an accessible method (that is, one that can be invoked via reflection) that implements the specified Method.
      private static java.lang.reflect.Method getAccessibleMethodFromInterfaceNest​(java.lang.Class<?> clazz, java.lang.String methodName, java.lang.Class<?>[] parameterTypes)
      Return an accessible method (that is, one that can be invoked via reflection) that implements the specified method, by scanning through all implemented interfaces and subinterfaces.
      private static java.lang.reflect.Method getAccessibleMethodFromSuperclass​(java.lang.Class<?> clazz, java.lang.String methodName, java.lang.Class<?>[] parameterTypes)
      Return an accessible method (that is, one that can be invoked via reflection) by scanning through the superclasses.
      private static java.lang.reflect.Method getCachedMethod​(MethodUtils.MethodDescriptor md)
      Return the method from the cache, if present.
      static java.lang.reflect.Method getMatchingAccessibleMethod​(java.lang.Class<?> clazz, java.lang.String methodName, java.lang.Class<?>[] parameterTypes)
      Find an accessible method that matches the given name and has compatible parameters.
      private static float getObjectTransformationCost​(java.lang.Class<?> srcClass, java.lang.Class<?> destClass)
      Gets the number of steps required needed to turn the source class into the destination class.
      static java.lang.Class<?> getPrimitiveType​(java.lang.Class<?> wrapperType)
      Gets the class for the primitive type corresponding to the primitive wrapper class given.
      static java.lang.Class<?> getPrimitiveWrapper​(java.lang.Class<?> primitiveType)
      Gets the wrapper object class for the given primitive type class.
      private static float getTotalTransformationCost​(java.lang.Class<?>[] srcArgs, java.lang.Class<?>[] destArgs)
      Returns the sum of the object transformation cost for each class in the source argument list.
      static java.lang.Object invokeExactMethod​(java.lang.Object object, java.lang.String methodName, java.lang.Object arg)
      Invoke a method whose parameter type matches exactly the object type.
      static java.lang.Object invokeExactMethod​(java.lang.Object object, java.lang.String methodName, java.lang.Object[] args)
      Invoke a method whose parameter types match exactly the object types.
      static java.lang.Object invokeExactMethod​(java.lang.Object object, java.lang.String methodName, java.lang.Object[] args, java.lang.Class<?>[] parameterTypes)
      Invoke a method whose parameter types match exactly the parameter types given.
      static java.lang.Object invokeExactStaticMethod​(java.lang.Class<?> objectClass, java.lang.String methodName, java.lang.Object arg)
      Invoke a static method whose parameter type matches exactly the object type.
      static java.lang.Object invokeExactStaticMethod​(java.lang.Class<?> objectClass, java.lang.String methodName, java.lang.Object[] args)
      Invoke a static method whose parameter types match exactly the object types.
      static java.lang.Object invokeExactStaticMethod​(java.lang.Class<?> objectClass, java.lang.String methodName, java.lang.Object[] args, java.lang.Class<?>[] parameterTypes)
      Invoke a static method whose parameter types match exactly the parameter types given.
      static java.lang.Object invokeMethod​(java.lang.Object object, java.lang.String methodName, java.lang.Object arg)
      Invoke a named method whose parameter type matches the object type.
      static java.lang.Object invokeMethod​(java.lang.Object object, java.lang.String methodName, java.lang.Object[] args)
      Invoke a named method whose parameter type matches the object type.
      static java.lang.Object invokeMethod​(java.lang.Object object, java.lang.String methodName, java.lang.Object[] args, java.lang.Class<?>[] parameterTypes)
      Invoke a named method whose parameter type matches the object type.
      static java.lang.Object invokeStaticMethod​(java.lang.Class<?> objectClass, java.lang.String methodName, java.lang.Object arg)
      Invoke a named static method whose parameter type matches the object type.
      static java.lang.Object invokeStaticMethod​(java.lang.Class<?> objectClass, java.lang.String methodName, java.lang.Object[] args)
      Invoke a named static method whose parameter type matches the object type.
      static java.lang.Object invokeStaticMethod​(java.lang.Class<?> objectClass, java.lang.String methodName, java.lang.Object[] args, java.lang.Class<?>[] parameterTypes)
      Invoke a named static method whose parameter type matches the object type.
      static boolean isAssignmentCompatible​(java.lang.Class<?> parameterType, java.lang.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.
      private static void setMethodAccessible​(java.lang.reflect.Method method)
      Try to make the method accessible
      private static java.lang.Object[] toArray​(java.lang.Object arg)  
      static java.lang.Class<?> toNonPrimitiveClass​(java.lang.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
    • Field Detail

      • loggedAccessibleWarning

        private static boolean loggedAccessibleWarning
        Only log warning about accessibility work around once.

        Note that this is broken when this class is deployed via a shared classloader in a container, as the warning message will be emitted only once, not once per webapp. However making the warning appear once per webapp means having a map keyed by context classloader which introduces nasty memory-leak problems. As this warning is really optional we can ignore this problem; only one of the webapps will get the warning in its logs but that should be good enough.

      • CACHE_METHODS

        private static boolean CACHE_METHODS
        Indicates whether methods should be cached for improved performance.

        Note that when this class is deployed via a shared classloader in a container, this will affect all webapps. However making this configurable per webapp would mean having a map keyed by context classloader which may introduce memory-leak problems.

      • EMPTY_CLASS_PARAMETERS

        private static final java.lang.Class<?>[] EMPTY_CLASS_PARAMETERS
        An empty class array
      • EMPTY_OBJECT_ARRAY

        private static final java.lang.Object[] EMPTY_OBJECT_ARRAY
        An empty object array
      • cache

        private static final java.util.Map<MethodUtils.MethodDescriptor,​java.lang.ref.Reference<java.lang.reflect.Method>> cache
        Stores a cache of MethodDescriptor -> Method in a WeakHashMap.

        The keys into this map only ever exist as temporary variables within methods of this class, and are never exposed to users of this class. This means that the WeakHashMap is used only as a mechanism for limiting the size of the cache, ie a way to tell the garbage collector that the contents of the cache can be completely garbage-collected whenever it needs the memory. Whether this is a good approach to this problem is doubtful; something like the commons-collections LRUMap may be more appropriate (though of course selecting an appropriate size is an issue).

        This static variable is safe even when this code is deployed via a shared classloader because it is keyed via a MethodDescriptor object which has a Class as one of its members and that member is used in the MethodDescriptor.equals method. So two components that load the same class via different classloaders will generate non-equal MethodDescriptor objects and hence end up with different entries in the map.

    • 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 java.lang.Object invokeMethod​(java.lang.Object object,
                                                    java.lang.String methodName,
                                                    java.lang.Object arg)
                                             throws java.lang.NoSuchMethodException,
                                                    java.lang.IllegalAccessException,
                                                    java.lang.reflect.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:
        java.lang.NoSuchMethodException - if there is no such accessible method
        java.lang.reflect.InvocationTargetException - wraps an exception thrown by the method invoked
        java.lang.IllegalAccessException - if the requested method is not accessible via reflection
      • invokeMethod

        public static java.lang.Object invokeMethod​(java.lang.Object object,
                                                    java.lang.String methodName,
                                                    java.lang.Object[] args)
                                             throws java.lang.NoSuchMethodException,
                                                    java.lang.IllegalAccessException,
                                                    java.lang.reflect.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:
        java.lang.NoSuchMethodException - if there is no such accessible method
        java.lang.reflect.InvocationTargetException - wraps an exception thrown by the method invoked
        java.lang.IllegalAccessException - if the requested method is not accessible via reflection
      • invokeMethod

        public static java.lang.Object invokeMethod​(java.lang.Object object,
                                                    java.lang.String methodName,
                                                    java.lang.Object[] args,
                                                    java.lang.Class<?>[] parameterTypes)
                                             throws java.lang.NoSuchMethodException,
                                                    java.lang.IllegalAccessException,
                                                    java.lang.reflect.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:
        java.lang.NoSuchMethodException - if there is no such accessible method
        java.lang.reflect.InvocationTargetException - wraps an exception thrown by the method invoked
        java.lang.IllegalAccessException - if the requested method is not accessible via reflection
      • invokeExactMethod

        public static java.lang.Object invokeExactMethod​(java.lang.Object object,
                                                         java.lang.String methodName,
                                                         java.lang.Object arg)
                                                  throws java.lang.NoSuchMethodException,
                                                         java.lang.IllegalAccessException,
                                                         java.lang.reflect.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:
        java.lang.NoSuchMethodException - if there is no such accessible method
        java.lang.reflect.InvocationTargetException - wraps an exception thrown by the method invoked
        java.lang.IllegalAccessException - if the requested method is not accessible via reflection
      • invokeExactMethod

        public static java.lang.Object invokeExactMethod​(java.lang.Object object,
                                                         java.lang.String methodName,
                                                         java.lang.Object[] args)
                                                  throws java.lang.NoSuchMethodException,
                                                         java.lang.IllegalAccessException,
                                                         java.lang.reflect.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:
        java.lang.NoSuchMethodException - if there is no such accessible method
        java.lang.reflect.InvocationTargetException - wraps an exception thrown by the method invoked
        java.lang.IllegalAccessException - if the requested method is not accessible via reflection
      • invokeExactMethod

        public static java.lang.Object invokeExactMethod​(java.lang.Object object,
                                                         java.lang.String methodName,
                                                         java.lang.Object[] args,
                                                         java.lang.Class<?>[] parameterTypes)
                                                  throws java.lang.NoSuchMethodException,
                                                         java.lang.IllegalAccessException,
                                                         java.lang.reflect.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:
        java.lang.NoSuchMethodException - if there is no such accessible method
        java.lang.reflect.InvocationTargetException - wraps an exception thrown by the method invoked
        java.lang.IllegalAccessException - if the requested method is not accessible via reflection
      • invokeExactStaticMethod

        public static java.lang.Object invokeExactStaticMethod​(java.lang.Class<?> objectClass,
                                                               java.lang.String methodName,
                                                               java.lang.Object[] args,
                                                               java.lang.Class<?>[] parameterTypes)
                                                        throws java.lang.NoSuchMethodException,
                                                               java.lang.IllegalAccessException,
                                                               java.lang.reflect.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:
        java.lang.NoSuchMethodException - if there is no such accessible method
        java.lang.reflect.InvocationTargetException - wraps an exception thrown by the method invoked
        java.lang.IllegalAccessException - if the requested method is not accessible via reflection
        Since:
        1.8.0
      • invokeStaticMethod

        public static java.lang.Object invokeStaticMethod​(java.lang.Class<?> objectClass,
                                                          java.lang.String methodName,
                                                          java.lang.Object arg)
                                                   throws java.lang.NoSuchMethodException,
                                                          java.lang.IllegalAccessException,
                                                          java.lang.reflect.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:
        java.lang.NoSuchMethodException - if there is no such accessible method
        java.lang.reflect.InvocationTargetException - wraps an exception thrown by the method invoked
        java.lang.IllegalAccessException - if the requested method is not accessible via reflection
        Since:
        1.8.0
      • invokeStaticMethod

        public static java.lang.Object invokeStaticMethod​(java.lang.Class<?> objectClass,
                                                          java.lang.String methodName,
                                                          java.lang.Object[] args)
                                                   throws java.lang.NoSuchMethodException,
                                                          java.lang.IllegalAccessException,
                                                          java.lang.reflect.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:
        java.lang.NoSuchMethodException - if there is no such accessible method
        java.lang.reflect.InvocationTargetException - wraps an exception thrown by the method invoked
        java.lang.IllegalAccessException - if the requested method is not accessible via reflection
        Since:
        1.8.0
      • invokeStaticMethod

        public static java.lang.Object invokeStaticMethod​(java.lang.Class<?> objectClass,
                                                          java.lang.String methodName,
                                                          java.lang.Object[] args,
                                                          java.lang.Class<?>[] parameterTypes)
                                                   throws java.lang.NoSuchMethodException,
                                                          java.lang.IllegalAccessException,
                                                          java.lang.reflect.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:
        java.lang.NoSuchMethodException - if there is no such accessible method
        java.lang.reflect.InvocationTargetException - wraps an exception thrown by the method invoked
        java.lang.IllegalAccessException - if the requested method is not accessible via reflection
        Since:
        1.8.0
      • invokeExactStaticMethod

        public static java.lang.Object invokeExactStaticMethod​(java.lang.Class<?> objectClass,
                                                               java.lang.String methodName,
                                                               java.lang.Object arg)
                                                        throws java.lang.NoSuchMethodException,
                                                               java.lang.IllegalAccessException,
                                                               java.lang.reflect.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:
        java.lang.NoSuchMethodException - if there is no such accessible method
        java.lang.reflect.InvocationTargetException - wraps an exception thrown by the method invoked
        java.lang.IllegalAccessException - if the requested method is not accessible via reflection
        Since:
        1.8.0
      • invokeExactStaticMethod

        public static java.lang.Object invokeExactStaticMethod​(java.lang.Class<?> objectClass,
                                                               java.lang.String methodName,
                                                               java.lang.Object[] args)
                                                        throws java.lang.NoSuchMethodException,
                                                               java.lang.IllegalAccessException,
                                                               java.lang.reflect.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:
        java.lang.NoSuchMethodException - if there is no such accessible method
        java.lang.reflect.InvocationTargetException - wraps an exception thrown by the method invoked
        java.lang.IllegalAccessException - if the requested method is not accessible via reflection
        Since:
        1.8.0
      • toArray

        private static java.lang.Object[] toArray​(java.lang.Object arg)
      • getAccessibleMethod

        public static java.lang.reflect.Method getAccessibleMethod​(java.lang.Class<?> clazz,
                                                                   java.lang.String methodName,
                                                                   java.lang.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 java.lang.reflect.Method getAccessibleMethod​(java.lang.Class<?> clazz,
                                                                   java.lang.String methodName,
                                                                   java.lang.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 java.lang.reflect.Method getAccessibleMethod​(java.lang.reflect.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 java.lang.reflect.Method getAccessibleMethod​(java.lang.Class<?> clazz,
                                                                   java.lang.reflect.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
      • getAccessibleMethodFromSuperclass

        private static java.lang.reflect.Method getAccessibleMethodFromSuperclass​(java.lang.Class<?> clazz,
                                                                                  java.lang.String methodName,
                                                                                  java.lang.Class<?>[] parameterTypes)

        Return an accessible method (that is, one that can be invoked via reflection) by scanning through the superclasses. If no such method can be found, return null.

        Parameters:
        clazz - Class to be checked
        methodName - Method name of the method we wish to call
        parameterTypes - The parameter type signatures
      • getAccessibleMethodFromInterfaceNest

        private static java.lang.reflect.Method getAccessibleMethodFromInterfaceNest​(java.lang.Class<?> clazz,
                                                                                     java.lang.String methodName,
                                                                                     java.lang.Class<?>[] parameterTypes)

        Return an accessible method (that is, one that can be invoked via reflection) that implements the specified method, by scanning through all implemented interfaces and subinterfaces. If no such method can be found, return null.

        There isn't any good reason why this method must be private. It is because there doesn't seem any reason why other classes should call this rather than the higher level methods.

        Parameters:
        clazz - Parent class for the interfaces to be checked
        methodName - Method name of the method we wish to call
        parameterTypes - The parameter type signatures
      • getMatchingAccessibleMethod

        public static java.lang.reflect.Method getMatchingAccessibleMethod​(java.lang.Class<?> clazz,
                                                                           java.lang.String methodName,
                                                                           java.lang.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
      • setMethodAccessible

        private static void setMethodAccessible​(java.lang.reflect.Method method)
        Try to make the method accessible
        Parameters:
        method - The source arguments
      • getTotalTransformationCost

        private static float getTotalTransformationCost​(java.lang.Class<?>[] srcArgs,
                                                        java.lang.Class<?>[] destArgs)
        Returns the sum of the object transformation cost for each class in the source argument list.
        Parameters:
        srcArgs - The source arguments
        destArgs - The destination arguments
        Returns:
        The total transformation cost
      • getObjectTransformationCost

        private static float getObjectTransformationCost​(java.lang.Class<?> srcClass,
                                                         java.lang.Class<?> destClass)
        Gets the number of steps required needed to turn the source class into the destination class. This represents the number of steps in the object hierarchy graph.
        Parameters:
        srcClass - The source class
        destClass - The destination class
        Returns:
        The cost of transforming an object
      • isAssignmentCompatible

        public static final boolean isAssignmentCompatible​(java.lang.Class<?> parameterType,
                                                           java.lang.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 java.lang.Class<?> getPrimitiveWrapper​(java.lang.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 java.lang.Class<?> getPrimitiveType​(java.lang.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 java.lang.Class<?> toNonPrimitiveClass​(java.lang.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
      • getCachedMethod

        private static java.lang.reflect.Method getCachedMethod​(MethodUtils.MethodDescriptor md)
        Return the method from the cache, if present.
        Parameters:
        md - The method descriptor
        Returns:
        The cached method
      • cacheMethod

        private static void cacheMethod​(MethodUtils.MethodDescriptor md,
                                        java.lang.reflect.Method method)
        Add a method to the cache.
        Parameters:
        md - The method descriptor
        method - The method to cache