Try to invoke a method of the passed object. - Android java.lang.reflect

Android examples for java.lang.reflect:Method Invoke

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Description

Try to invoke a method of the passed object.

Demo Code


import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

public class Main{
    /**//from   ww  w  .j a v a 2  s .  com
     * Try to invoke a method of the passed object. It does not throw any exception if the methodName does not exist on the declared
     * class object
     * 
     * @param object
     * @param methodName
     * @param parameterTypes
     *           Parameter types of the invoking method
     * @param parameterValues
     *           Parameter values to be passed to the method being invoked
     * @return
     * @throws ReflectionException
     * @throws IllegalArgumentException
     *            if parameterTypes and parameterValues have different length
     */
    @SuppressWarnings("unchecked")
    public static <T> T invokeMethod(final Object object,
            final String methodName, final Class<?>[] parameterTypes,
            Object... parameterValues) throws ReflectionException {
        return (T) helper(object, null, methodName, parameterTypes,
                parameterValues);
    }
    /**
     * @see ReflectionUtils#invokeMethod(Object, String, Class[], Object...)
     * @param object
     * @param methodName
     * @return
     * @throws ReflectionException
     */
    @SuppressWarnings("unchecked")
    public static <T> T invokeMethod(Object object, String methodName)
            throws ReflectionException {
        return (T) helper(object, null, methodName, null, null);
    }
    @SuppressWarnings("unchecked")
    private static <T> T helper(Object target, final String className,
            final String methodName, final Class<?>[] argTypes,
            final Object[] args) throws ReflectionException {
        try {
            Class<?> cls;
            if (target != null) {
                cls = target.getClass();
            } else {
                cls = Class.forName(className);
                target = cls;
            }

            Method method;

            if (null != argTypes) {
                method = getMethod(cls, methodName, argTypes);
                return (T) method.invoke(target, args);
            } else {
                method = getMethod(cls, methodName);
                return (T) method.invoke(target);
            }

        } catch (final IllegalAccessException e) {
            throw new ReflectionException(e);
        } catch (final InvocationTargetException e) {
            throw new ReflectionException(e);
        } catch (final ClassNotFoundException e) {
            throw new ReflectionException(e);
        } catch (NullPointerException e) {
            throw new ReflectionException(e);
        }
    }
    public static Method getMethod(Class<?> classObject, String methodName,
            Class<?>[] paramTypes) {
        try {
            return classObject.getMethod(methodName, paramTypes);
        } catch (NoSuchMethodException e) {
        }
        return null;
    }
    public static Method getMethod(Class<?> classObject, String methodName) {
        try {
            return classObject.getMethod(methodName);
        } catch (NoSuchMethodException e) {
        }
        return null;
    }
}

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