Java Collection Join join(Collection collec, String delimiter)

Description

Serialize collection elements with a delimiter.

License

Apache License

Parameter

Parameter	Description
collec	collection (a,b,c)
delimiter	delimiter char (e.g : ",")

Return

the list : a,b,c

Declaration

public static <T> String join(Collection<T> collec, String delimiter) 

Method Source Code

//package com.java2s;
/*//from   ww  w  .  j  ava  2  s.c o m
 * #%L
 * ff4j-core
 * %%
 * Copyright (C) 2013 - 2014 Ff4J
 * %%
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * #L%
 */

import java.util.Collection;

public class Main {
    /**
     * Serialize collection elements with a delimiter.
     *
     * @param collec
     *      collection (a,b,c)
     * @param delimiter
     *      delimiter char (e.g : ",")
     * @return
     *      the list : a,b,c
     */
    public static <T> String join(Collection<T> collec, String delimiter) {
        assertNotNull(delimiter);
        if (collec == null)
            return null;
        StringBuilder sb = new StringBuilder();
        boolean first = true;
        for (T t : collec) {
            if (!first) {
                sb.append(",");
            }
            sb.append(t.toString());
            first = false;
        }
        return sb.toString();
    }

    /**
     * Check that object is not null.
     * 
     * @param object
     *            target object
     */
    public static void assertNotNull(Object... params) {
        assertNotNull("parameter", params);
    }

    /**
     * Check that object is not null.
     * 
     * @param object
     *            target object
     */
    public static void assertNotNull(String objectName, Object... params) {
        if (params == null) {
            throw new IllegalArgumentException("[Assertion failed] - " + objectName + " must not be null");
        }
        for (int idx = 0; idx < params.length; idx++) {
            Object currentparam = params[idx];
            if (null == currentparam) {
                throw new IllegalArgumentException("[Assertion failed] - " + objectName + " must not be null");
            }
        }
    }
}

Related

1. join(Collection thisPath, String _delim)
2. join(Collection values)
3. join(Collection words, String character)
4. join(Collection c, String concatinator)
5. join(Collection coll, String separator)
6. join(Collection collection, CharSequence joinedBy)
7. join(Collection collection, String joinString)
8. join(Collection collections, String separator)
9. join(Collection list, final String separator)