java Join

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;


public class Join {

    private static final String defaultSplit=",";

    public static String join(Object [] strings){
        return join(strings, defaultSplit);
    }

    public static String join(Collection<?> strings){
        return join(strings, defaultSplit);
    }

    public static String join(Object [] strings,String split){
        if(strings==null)
            return "";
        StringBuffer buffer=new StringBuffer();
        int size=strings.length;
        int i=0;
        for(Object obj:strings ){
            i++;
            buffer.append(String.valueOf(obj));
            if(i<size)
                buffer.append(split);
        }
        return buffer.toString();
    }

    public static String join(Collection<?> strings,String split){
        if(strings==null) {
            return "";
        }
        StringBuffer buffer=new StringBuffer();
        int size=strings.size();
        int i=0;
        for(Object obj:strings ){
            i++;
            buffer.append(String.valueOf(obj));
            if(i<size)
            buffer.append(split);
        }
        return buffer.toString();
    }

    public static String getDefaultSplit() {
        return defaultSplit;
    }

    public static void main(String ...arg){
        System.out.println(Join.join(Arrays.asList("1"),","));
    }
}