get Class Instance - Java Reflection

Java examples for Reflection:Class Loader

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Description

get Class Instance

Demo Code


//package com.java2s;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;

public class Main {
    public static Object getClassInstance(String className,
            Class[] paramTypes, Object[] params)
            throws ClassNotFoundException, SecurityException,
            NoSuchMethodException, IllegalArgumentException,
            InstantiationException, IllegalAccessException,
            InvocationTargetException {
        Object obj = null;//from w w w .  j av  a  2s.  c o  m
        Class actionClassObj;
        actionClassObj = Class.forName(className);
        Constructor cons = actionClassObj.getConstructor(paramTypes);
        obj = cons.newInstance(params);
        return obj;
    }

    public static <T> T getClassInstance(String className,
            Class[] paramTypes, Object[] params, Class<T> c)
            throws ClassNotFoundException, SecurityException,
            NoSuchMethodException, IllegalArgumentException,
            InstantiationException, IllegalAccessException,
            InvocationTargetException {
        Object obj = null;
        Class actionClassObj;
        actionClassObj = Class.forName(className);
        Constructor cons = actionClassObj.getConstructor(paramTypes);
        obj = cons.newInstance(params);
        return (T) obj;
    }

    public static Object getClassInstance(String className,
            Class[] paramTypes, Object[] params,
            ClassLoader customClassLoader) throws ClassNotFoundException,
            SecurityException, NoSuchMethodException,
            IllegalArgumentException, InstantiationException,
            IllegalAccessException, InvocationTargetException {
        Object obj = null;
        Class actionClassObj;
        actionClassObj = customClassLoader.loadClass(className);//, false, customClassLoader);
        Constructor cons = actionClassObj.getConstructor(paramTypes);
        obj = cons.newInstance(params);
        return obj;
    }
}

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