Java Iterable Join join(CharSequence delimiter, Iterable tokens)

Description

join

License

Apache License

Declaration

public static String join(CharSequence delimiter, Iterable tokens) 

Method Source Code

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

import java.util.List;

public class Main {
    /** default join separator **/
    public static final String DEFAULT_JOIN_SEPARATOR = ",";

    /**//ww w  . j  ava2  s .com
     * join list to string, separator is ","
     * 
     * <pre>
     * join(null)      =   "";
     * join({})        =   "";
     * join({a,b})     =   "a,b";
     * </pre>
     * 
     * @param list
     * @return join list to string, separator is ",". if list is empty, return ""
     */
    public static String join(List<String> list) {
        return join(list, DEFAULT_JOIN_SEPARATOR);
    }

    /**
     * join list to string
     * 
     * <pre>
     * join(null, '#')     =   "";
     * join({}, '#')       =   "";
     * join({a,b,c}, ' ')  =   "abc";
     * join({a,b,c}, '#')  =   "a#b#c";
     * </pre>
     * 
     * @param list
     * @param separator
     * @return join list to string. if list is empty, return ""
     */
    public static String join(List<String> list, char separator) {
        return join(list, new String(new char[] { separator }));
    }

    /**
     * join list to string. if separator is null, use {@link #DEFAULT_JOIN_SEPARATOR}
     * 
     * <pre>
     * join(null, "#")     =   "";
     * join({}, "#$")      =   "";
     * join({a,b,c}, null) =   "a,b,c";
     * join({a,b,c}, "")   =   "abc";
     * join({a,b,c}, "#")  =   "a#b#c";
     * join({a,b,c}, "#$") =   "a#$b#$c";
     * </pre>
     * 
     * @param list
     * @param separator
     * @return join list to string with separator. if list is empty, return ""
     */
    public static String join(List<String> list, String separator) {
        StringBuilder sb = new StringBuilder();
        boolean firstTime = true;
        for (Object token : list) {
            if (firstTime) {
                firstTime = false;
            } else {
                sb.append(separator);
            }
            sb.append(token);
        }
        return sb.toString();
    }

    public static String join(CharSequence delimiter, Iterable tokens) {
        StringBuilder sb = new StringBuilder();
        boolean firstTime = true;
        for (Object token : tokens) {
            if (firstTime) {
                firstTime = false;
            } else {
                sb.append(delimiter);
            }
            sb.append(token);
        }
        return sb.toString();
    }
}

Related

1. join(CharSequence delimiter, Iterable tokens)
2. join(CharSequence delimiter, Iterable elements)
3. join(CharSequence separator, Iterable strings)
4. join(final CharSequence sep, final Iterable src)