Java List First Item getFirstInstanceOf(List source, String className)

Description

get First Instance Of

License

Apache License

Declaration

public static Object getFirstInstanceOf(List source, String className) throws ClassNotFoundException 

Method Source Code

//package com.java2s;
//License from project: Apache License 

import java.util.List;

public class Main {
    public static Object getFirstInstanceOf(List source, String className) throws ClassNotFoundException {
        Class targetInstance = Class.forName(className);
        if (findInstanceOfClassExists(source, className)) {
            for (Object object : source) {

                if (targetInstance.isInstance(object))
                    return targetInstance.cast(object);

            }//from   w ww  . j  a  va 2  s  . co  m
        }
        return null;

    }

    /**
     * check whether the class mentioned does exist in 'list' -- source, return
     * true on first instance
     * 
     * @param source
     * @param className
     * @return
     * @throws ClassNotFoundException
     */
    public static boolean findInstanceOfClassExists(List source, String className) throws ClassNotFoundException {
        if (source == null)
            return false;
        if (className == null)
            return false;
        if (source.size() <= 0)
            return false;
        if (className.isEmpty())
            return false;
        Class targetInstance = Class.forName(className);

        for (Object object : source) {
            if (targetInstance.isInstance(object))
                return true;
        }

        return false;

    }
}

Related

1. getFirstElement(List collection)
2. getFirstElement(List list)
3. getFirstElement(List list)
4. getFirstElementFromList(List list)
5. getFirstFromList(List list)
6. getFirstItemOrNull(List items)
7. getFirstLeaf(List aList)
8. getFirstNameIndex(List list)
9. getFirstNonEmptyIndex(final List> list)