Package org.apache.commons.beanutils2

Class MethodUtils

java.lang.Object
org.apache.commons.beanutils2.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 privileges. If this call fails then a warning will be logged and the method may fail.

  • Constructor Details

  • Method Details

    • clearCache

      public static int clearCache()
      Clear the method cache.
      Returns:
      the number of cached methods cleared
      Since:
      1.8.0

    • 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

    • 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

    • 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 indeterministic 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</code> will match a primitive <code>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

    • 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</code> returns a <code>boolean.class.
      Parameters:
      wrapperType - the
      Returns:
      the primitive type class corresponding to the given wrapper class, null if no match is found

    • getPrimitiveWrapper

      public static Class<?> getPrimitiveWrapper(Class<?> primitiveType)
      Gets the wrapper object class for the given primitive type class. For example, passing boolean.class</code> returns <code>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

    • 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 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

    • 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

    • 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 behavior 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 behavior 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 behavior 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

    • 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 behavior 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 behavior 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 behavior 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

    • 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</code> to a <code>boolean, a Long</code> to a <code>long, a Float</code> to a <code>float, a Integer</code> to a <code>int, and a Double</code> to a <code>double. Now logic widening matches are allowed. For example, a Long</code> will not match a <code>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.

    • setCacheMethods

      public static void setCacheMethods(boolean cacheMethods)
      Sets 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

    • 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