Java Collection to String collectionToDelimitedString(Collection coll, String delim, String prefix, String suffix)

Description

Convenience method to return a Collection as a delimited (e.g.

License

Apache License

Parameter

Parameter	Description
coll	the Collection to display
delim	the delimiter to use (probably a ",")
prefix	the String to start each element with
suffix	the String to end each element with

Return

the delimited String

Declaration

public static String collectionToDelimitedString(Collection<?> coll, String delim, String prefix,
        String suffix) 

Method Source Code

//package com.java2s;
/*//from   w w  w.  j  ava 2  s.c  o  m
 * Copyright 2002-2012 the original author or authors.
 *
 * 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.
 */

import java.util.*;

public class Main {
    /**
     * Convenience method to return a Collection as a delimited (e.g. CSV)
     * String. E.g. useful for {@code toString()} implementations.
     *
     * @param coll   the Collection to display
     * @param delim  the delimiter to use (probably a ",")
     * @param prefix the String to start each element with
     * @param suffix the String to end each element with
     * @return the delimited String
     */
    public static String collectionToDelimitedString(Collection<?> coll, String delim, String prefix,
            String suffix) {
        if (coll == null || coll.isEmpty()) {
            return "";
        }
        StringBuilder sb = new StringBuilder();
        Iterator<?> it = coll.iterator();
        while (it.hasNext()) {
            sb.append(prefix).append(it.next()).append(suffix);
            if (it.hasNext()) {
                sb.append(delim);
            }
        }
        return sb.toString();
    }

    /**
     * Convenience method to return a Collection as a delimited (e.g. CSV)
     * String. E.g. useful for {@code toString()} implementations.
     *
     * @param coll  the Collection to display
     * @param delim the delimiter to use (probably a ",")
     * @return the delimited String
     */
    public static String collectionToDelimitedString(Collection<?> coll, String delim) {
        return collectionToDelimitedString(coll, delim, "", "");
    }

    /**
     * Check whether the given String is empty.
     * <p>This method accepts any Object as an argument, comparing it to
     * {@code null} and the empty String. As a consequence, this method
     * will never return {@code true} for a non-null non-String object.
     * <p>The Object signature is useful for general attribute handling code
     * that commonly deals with Strings but generally has to iterate over
     * Objects since attributes may e.g. be primitive value objects as well.
     *
     * @param str the candidate String
     * @since 3.2.1
     */
    public static boolean isEmpty(Object str) {
        return (str == null || "".equals(str));
    }

    public static boolean equals(String str1, String str2) {
        return str1 == null ? str2 == null : str1.equals(str2);
    }
}

Related

1. collectionToDelimitedString(Collection coll, String delim, String prefix, String suffix)
2. collectionToDelimitedString(Collection coll, String delim, String prefix, String suffix)
3. collectionToDelimitedString(Collection col, String del)
4. collectionToDelimitedString(Collection coll, String delim)
5. collectionToDelimitedString(Collection coll, String delim)
6. collectionToDelimitedString(Collection values, String delimiter)
7. collectionToStr(Collection collection)
8. CollectionToStr(Collection coll)
9. collectionToStr(Collection collection)