Java String Join joinMap(String keyValueSeperator, String recordSeperator, Map map)

Here you can find the source of joinMap(String keyValueSeperator, String recordSeperator, Map map)

Description

join the key value pairs of a map into one string, i.e.

License

Open Source License

Parameter

Parameter Description
keyValueSeperator the string to seperate the key-value pairs
recordSeperator the string to use to seperate each key-value pair from other key-value pairs
map the map to draw from
L the map's key type
R the map's value type

Return

a string representing the joined map

Declaration

public static <L, R> String joinMap(String keyValueSeperator, String recordSeperator, Map<L, R> map) 

Method Source Code

//package com.java2s;
/*/* w  w w  .  ja v  a2s  .  c om*/
 * Copyright (c) 2010 The Broad Institute
 *
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use,
 * copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following
 * conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR
 * THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

import java.util.*;

public class Main {
    /**
     * join the key value pairs of a map into one string, i.e. myMap = [A->1,B->2,C->3] with a call of:
     * joinMap("-","*",myMap) -> returns A-1*B-2*C-3
     *
     * Be forewarned, if you're not using a map that is aware of the ordering (i.e. HashMap instead of LinkedHashMap)
     * the ordering of the string you get back might not be what you expect! (i.e. C-3*A-1*B-2 vrs A-1*B-2*C-3)
     *
     * @param keyValueSeperator the string to seperate the key-value pairs
     * @param recordSeperator the string to use to seperate each key-value pair from other key-value pairs
     * @param map the map to draw from
     * @param <L> the map's key type
     * @param <R> the map's value type
     * @return a string representing the joined map
     */
    public static <L, R> String joinMap(String keyValueSeperator, String recordSeperator, Map<L, R> map) {
        if (map.size() < 1) {
            return null;
        }
        String joinedKeyValues[] = new String[map.size()];
        int index = 0;
        for (L key : map.keySet()) {
            joinedKeyValues[index++] = String.format("%s%s%s", key.toString(), keyValueSeperator,
                    map.get(key).toString());
        }
        return join(recordSeperator, joinedKeyValues);
    }

    /**
     * join an array of strings given a seperator
     * @param separator the string to insert between each array element
     * @param strings the array of strings
     * @return a string, which is the joining of all array values with the separator
     */
    public static String join(String separator, String[] strings) {
        return join(separator, strings, 0, strings.length);
    }

    public static String join(String separator, String[] strings, int start, int end) {
        if ((end - start) == 0) {
            return "";
        }
        StringBuilder ret = new StringBuilder(strings[start]);
        for (int i = start + 1; i < end; ++i) {
            ret.append(separator);
            ret.append(strings[i]);
        }
        return ret.toString();
    }

    /**
     * Returns a string of the form elt1.toString() [sep elt2.toString() ... sep elt.toString()] for a collection of
     * elti objects (note there's no actual space between sep and the elti elements).  Returns
     * "" if collection is empty.  If collection contains just elt, then returns elt.toString()
     *
     * @param separator the string to use to separate objects
     * @param objects a collection of objects.  the element order is defined by the iterator over objects
     * @param <T> the type of the objects
     * @return a non-null string
     */
    public static <T> String join(final String separator, final Collection<T> objects) {
        if (objects.isEmpty()) { // fast path for empty collection
            return "";
        } else {
            final Iterator<T> iter = objects.iterator();
            final T first = iter.next();

            if (!iter.hasNext()) // fast path for singleton collections
                return first.toString();
            else { // full path for 2+ collection that actually need a join
                final StringBuilder ret = new StringBuilder(first.toString());
                while (iter.hasNext()) {
                    ret.append(separator);
                    ret.append(iter.next().toString());
                }
                return ret.toString();
            }
        }
    }
}

Related

  1. join2(String connector, String... strs)
  2. joinColumns(Iterable columns)
  3. joinedList(T first, T... others)
  4. joinIterable(Iterable element, String separator)
  5. joinMap(Map map)
  6. JoinMaps(Map into, Map other)
  7. joinPath(String part1, String part2)
  8. joinPaths(String... paths)
  9. joinRepeat(int size, String s, String delim)