2个文件中的单词频率计数

我已经编写了Java代码来对发生的总数进行计数。它使用2个.txt文件作为输入，并给出单词和频率作为输出。

我也想打印，哪个文件包含一个给定的单词多少次。你有什么想法吗？

public class JavaApplication2
{

    public static void main(String[] args) throws IOException
    {     
        Path filePath1 = Paths.get("test.txt");
        Path filePath2 = Paths.get("test2.txt");

        Scanner readerL = new Scanner(filePath1);
        Scanner readerR = new Scanner(filePath2);

        String line1 = readerL.nextLine();
        String line2 = readerR.nextLine();

        String text = new String();
        text=text.concat(line1).concat(line2);

        String[] keys = text.split("[!.?:;\\s]");
        String[] uniqueKeys;
        int count = 0;
        System.out.println(text);
        uniqueKeys = getUniqueKeys(keys);

        for(String key: uniqueKeys)
        {
            if(null == key)
            {
                break;
            }           
            for(String s : keys)
            {
                if(key.equals(s))
                {
                    count++;
                }               
            }
            System.out.println("["+key+"] frequency : "+count);
            count=0;
        }
    }

    private static String[] getUniqueKeys(String[] keys)
    {
        String[] uniqueKeys = new String[keys.length];

        uniqueKeys[0] = keys[0];
        int uniqueKeyIndex = 1;
        boolean keyAlreadyExists = false;

        for(int i=1; i<keys.length ; i++)
        {
            for(int j=0; j<=uniqueKeyIndex; j++)
            {
                if(keys[i].equals(uniqueKeys[j]))
                {
                    keyAlreadyExists = true;
                }
            }           

            if(!keyAlreadyExists)
            {
                uniqueKeys[uniqueKeyIndex] = keys[i];
                uniqueKeyIndex++;               
            }
            keyAlreadyExists = false;
        }       
        return uniqueKeys;
    }