Description
Invoke the given method.
License
Open Source License
Parameter
| Parameter | Description |
|---|
| methodName | The method name |
| target | The target Object |
| targetClass | The Class of the target object |
| args | An array of argument Objects |
Exception
| Parameter | Description |
|---|
| IllegalAccessException | an exception |
| IllegalArgumentException | an exception |
| InvocationTargetException | an exception |
| NoSuchMethodException | an exception |
| SecurityException | an exception |
Return
The return value
Declaration
public static Object invoke(String methodName, Object target, Class targetClass, Object[] args)
throws IllegalAccessException, IllegalArgumentException, InvocationTargetException,
NoSuchMethodException, SecurityException
Method Source Code
//package com.java2s;
import java.lang.reflect.Method;
import java.lang.reflect.InvocationTargetException;
public class Main {
private static final Object[] EMPTY_OBJECT_ARRAY = new Object[0];
private static final Class[] EMPTY_CLASS_ARRAY = new Class[0];
/** Invoke the given method. This method is a convenience method which
creates an array of arguments with the single arg value. This is
necessary because the Method.invoke() method only accepts an array of
argument objects.//from w ww . j a v a 2s. co m
@param method The method
@param target The target Object
@param arg A single argument
@return The return object or null
@throws IllegalAccessException
@throws IllegalArgumentException
@throws InvocationTargetException
*/
public static Object invoke(Method method, Object target, Object arg)
throws IllegalAccessException, IllegalArgumentException, InvocationTargetException {
if (arg == null) {
return invoke(method, target, EMPTY_OBJECT_ARRAY);
} else {
Object[] args = new Object[1];
args[0] = arg;
return invoke(method, target, args);
}
}
/** Invoke the given method. This method actually invokes the target
method with the given arguments.
@param method The Method
@param target The target Object
@param args An array of argument Objects
@return The return value
@throws IllegalAccessException
@throws IllegalArgumentException
@throws InvocationTargetException
*/
public static Object invoke(Method method, Object target, Object[] args)
throws IllegalAccessException, IllegalArgumentException, InvocationTargetException {
return method.invoke(target, args);
}
/** Invoke the given method. The target object is used to determine
the target class and which is then used to get a Method object.
This method is a convenience method which creates an array of arguments
with the single arg value. This is necessary because the
Method.invoke() method only accepts an array of argument objects.
@param methodName The method name
@param target The target Object
@param arg A single argument
@return The return object or null
@throws IllegalAccessException
@throws IllegalArgumentException
@throws InvocationTargetException
@throws NoSuchMethodException
@throws SecurityException
*/
public static Object invoke(String methodName, Object target, Object arg) throws IllegalAccessException,
IllegalArgumentException, InvocationTargetException, NoSuchMethodException, SecurityException {
if (arg == null) {
return invoke(methodName, target, EMPTY_OBJECT_ARRAY);
} else {
Object[] args = new Object[1];
args[0] = arg;
return invoke(methodName, target, args);
}
}
/** Invoke the given method. The target object is used to determine
the target class and which is then used to get a Method object.
@param methodName The Method name
@param target The target Object
@param args An array of argument Objects
@return The return value
@throws IllegalAccessException
@throws IllegalArgumentException
@throws InvocationTargetException
@throws NoSuchMethodException
@throws SecurityException
*/
public static Object invoke(String methodName, Object target, Object[] args) throws IllegalAccessException,
IllegalArgumentException, InvocationTargetException, NoSuchMethodException, SecurityException {
return invoke(methodName, target, target.getClass(), args);
}
/** Invoke the given method. The target object may be null in which
case the target class is used and the method must be a static
method.
@param methodName The method name
@param target The target Object
@param targetClass The Class of the target object
@param args An array of argument Objects
@return The return value
@throws IllegalAccessException
@throws IllegalArgumentException
@throws InvocationTargetException
@throws NoSuchMethodException
@throws SecurityException
*/
public static Object invoke(String methodName, Object target, Class targetClass, Object[] args)
throws IllegalAccessException, IllegalArgumentException, InvocationTargetException,
NoSuchMethodException, SecurityException {
Class[] paramClasses = new Class[args.length];
for (int i = 0; i < args.length; i++) {
paramClasses[i] = args[i].getClass();
}
Method method = getMethod(targetClass, methodName, paramClasses);
return invoke(method, target, args);
}
/** Invoke the given method. This method is a convenience method for
invoking single argument methods.
@param methodName The method name
@param target The target Object
@param targetClass The Class of the target object
@param arg A single argument
@return The return value
@throws IllegalAccessException
@throws IllegalArgumentException
@throws InvocationTargetException
@throws NoSuchMethodException
@throws SecurityException
*/
public static Object invoke(String methodName, Object target, Class targetClass, Object arg)
throws IllegalAccessException, IllegalArgumentException, InvocationTargetException,
NoSuchMethodException, SecurityException {
if (arg == null) {
return invoke(methodName, target, targetClass, EMPTY_OBJECT_ARRAY);
} else {
Object[] args = new Object[1];
args[0] = arg;
return invoke(methodName, target, targetClass, args);
}
}
/** Get the method with the given name and with a single argument of the
type specified by paramClass. The paramClass may be null in which case
the method should have no arguments.
@param targetClass The target class
@param name The method name
@param paramClass The single parameter class (may be null)
@return The Method
@throws SecurityException
@throws NoSuchMethodException
*/
public static Method getMethod(Class targetClass, String name, Class paramClass)
throws NoSuchMethodException, SecurityException {
if (paramClass == null) {
return getMethod(targetClass, name, EMPTY_CLASS_ARRAY);
} else {
Class[] paramClasses = new Class[1];
paramClasses[0] = paramClass;
return getMethod(targetClass, name, paramClasses);
}
}
/** Get the method with the given name and with arguments of the
types specified by paramClasses. If the method is not found
then a method which accepts superclasses of the current arguments
will be returned, if possible.
@param targetClass The target class
@param name The method name
@param paramClasses An array of parameter classes
@return The Method
@throws SecurityException
@throws NoSuchMethodException
*/
public static Method getMethod(Class targetClass, String name, Class[] paramClasses)
throws NoSuchMethodException, SecurityException {
Method method = null;
try {
method = targetClass.getMethod(name, paramClasses);
} catch (NoSuchMethodException nsme) {
Method[] methods = targetClass.getMethods();
OUTER: for (int i = 0; i < methods.length; i++) {
if (methods[i].getName().equalsIgnoreCase(name)
&& methods[i].getParameterTypes().length == paramClasses.length) {
Class[] params = methods[i].getParameterTypes();
for (int j = 0; j < params.length; j++) {
if (!params[j].isAssignableFrom(paramClasses[j])) {
continue OUTER;
}
}
method = methods[i];
break;
}
}
if (method == null) {
throw nsme;
}
}
return method;
}
}
Related
- invoke(String className, String methodName, Class[] paramTypes, Object... params)
- invoke(String cls_name, String method, Class[] param_cls, Object cls, Object[] params)
- invoke(String method)
- invoke(String methodName, Object obj)
- invoke(String methodName, Object object, Class[] argTypes, Object[] args)
- invoke(String name, Object object, Object... args)
- invoke_ex(Object obj, String method, Class[] params, Object[] args)
- invokeAccessableMethodWithArguments(Object instance, String method, Object... arguments)
- invokeAndCastCollection(T returnType, Method m, Object obj, Object... args)