Java - Write code to Join 0..n strings separated by a delimiter.

Requirements

Write code to Join 0..n strings separated by a delimiter.

Demo

//package com.book2s;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.io.Writer;

import java.util.Iterator;

public class Main {
    public static void main(String[] argv) {
        String delimiter = "book2s.com";
        Iterator iterator = java.util.Arrays.asList("asdf", "book2s.com")
                .iterator();//  ww w .  ja  v  a2s . co  m
        System.out.println(join(delimiter, iterator));
    }

    public static String join(final String delimiter,
            final Iterator<?> iterator) {
        if (iterator == null) {
            return null;
        }

        final StringBuilder sb = new StringBuilder();
        while (iterator.hasNext()) {
            sb.append(iterator.next().toString());
            sb.append(delimiter);
        }
        // remove last delimiter
        final int bufLen = sb.length();
        if (bufLen > 0) { // only removed if we ever added anything
            sb.delete(bufLen - delimiter.length(), bufLen);
        }
        return sb.toString();
    }
    public static String join(final String delimiter,
            final String... strings) {
        if (strings == null) {
            return null;
        }
        if (strings.length == 0) {
            return "";
        }
        final StringBuilder sb = new StringBuilder();

        // add first 1.. n-1
        final int len = strings.length - 1;
        int i = 0;
        for (; i < len; i++) {
            sb.append(strings[i]);
            sb.append(delimiter);
        }
        // add last
        sb.append(strings[i]);
        return sb.toString();
    }
    public static String toString(final Throwable throwable) {
        final Writer result = new StringWriter();
        final PrintWriter printWriter = new PrintWriter(result);
        throwable.printStackTrace(printWriter);
        return result.toString();
    }
}

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