net.sf.basedb.util
Class ClassUtil

java.lang.Object
  net.sf.basedb.util.ClassUtil

public class ClassUtil
extends Object

Utility class for Class objects.

Version:

2.0

Author:

Nicklas

Last modified

$Date: 2009-04-06 14:52:39 +0200 (Mon, 06 Apr 2009) $

Constructor Summary

ClassUtil()

Method Summary

static Class<?>	checkAndLoadClass(ClassLoader loader, String name, boolean publicNoArgConstructor, Class<?>... interfaces) Check if a specified class exists and, optionally, if it has public no-argument constructor and implements a set of specific interfaces or superclasses.
static void	checkClass(Class<?> clazz, boolean publicNoArgConstructor, Class<?>... interfaces) Check if a specified class has public no-argument constructor and implements a set of specific interfaces or superclasses.
static <I> Constructor<I>	findConstructor(Class<I> clazz, Object[] parameters) Find a constructor for the specified class which takes parameters of the specified types taking superclasses and interfaces into account.
static Method	findMethod(Class<?> clazz, String name, Class<?>... arguments) Find a method in a clazz with the given name that takes the given list of arguments.
static Set<Class>	getInterfaces(Class clazz) Get all interfaces a class implements, including those implemented by superclasses.
static boolean	isAssignable(Class<?>[] classes, Object[] values) Check if one array of class objects is assignment compatible with values in another array.

Methods inherited from class java.lang.Object

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

Constructor Detail

ClassUtil

public ClassUtil()

Method Detail

findConstructor

public static <I> Constructor<I> findConstructor(Class<I> clazz,
                                                 Object[] parameters)

Find a constructor for the specified class which takes parameters of the specified types taking superclasses and interfaces into account. This method finds the first declared constructor which can accept parameters of the specified type.

Parameters:

clazz - The class to find a constructor for

parameters - The parameters that are going to be sent to the constructor's Constructor.newInstance(Object[]) method

Returns:

A constructor object or null if no constructor was found

isAssignable

public static boolean isAssignable(Class<?>[] classes,
                                   Object[] values)

Check if one array of class objects is assignment compatible with values in another array. Ie. the Class.isAssignableFrom(Class) method returns true for each element in the classes array with respect to the class of the corresponding value in the values array. Null elements in the values array are ignored.

Parameters:

classes - The class objects representing the parameters we want to assign values to

values - The parameter values to assign

Returns:

TRUE if all parameters are assignable

getInterfaces

public static Set<Class> getInterfaces(Class clazz)

Get all interfaces a class implements, including those implemented by superclasses.

Parameters:

clazz - The Class to check

Returns:

A Set containing the Class objects for the interfaces

checkAndLoadClass

public static Class<?> checkAndLoadClass(ClassLoader loader,
                                         String name,
                                         boolean publicNoArgConstructor,
                                         Class<?>... interfaces)
                                  throws ClassNotFoundException,
                                         NoSuchMethodException,
                                         ClassCastException

Check if a specified class exists and, optionally, if it has public no-argument constructor and implements a set of specific interfaces or superclasses.

Parameters:

loader - The classloader used to load the class, or null to use the default classloader

name - The fully qualified name of class to check

publicNoArgConstructor - TRUE to check if a public no-argument constructor exists

interfaces - An array of class objects representing interfaces or superclasses that the class to check must implement or extend

Returns:

The Class object for the named class

Throws:

ClassNotFoundException - If a class with the specified name isn't found

NoSuchMethodException - If a public no-argument constructor isn't found

ClassCastException - If the class doesn't implement or extend all of the interfaces/superclasses

Since:

2.5

checkClass

public static void checkClass(Class<?> clazz,
                              boolean publicNoArgConstructor,
                              Class<?>... interfaces)
                       throws NoSuchMethodException,
                              ClassCastException

Check if a specified class has public no-argument constructor and implements a set of specific interfaces or superclasses.

Parameters:

clazz - The clazz to check

publicNoArgConstructor - TRUE to check if a public no-argument constructor exists

interfaces - An array of class objects representing interfaces or superclasses that the class to check must implement or extend

Throws:

NoSuchMethodException - If a public no-argument constructor isn't found

ClassCastException - If the class doesn't implement or extend all of the interfaces/superclasses

Since:

2.10

findMethod

public static Method findMethod(Class<?> clazz,
                                String name,
                                Class<?>... arguments)

Find a method in a clazz with the given name that takes the given list of arguments. This method is just calling Class.getMethod(String, Class...) but returns null instead of throwing an exception in case the method is not found.

Parameters:

clazz - The class to look for the method in

name - The name of the method

arguments - The class types of the arguments

Returns:

The method or null if not found

Since:

2.7