Java Collection Join join(Collection items, char separator)

Description

Creates a backslash escaped string, joining all the items.

License

Apache License

Declaration

public static String join(Collection<?> items, char separator) 

Method Source Code

//package com.java2s;
/*/*  ww w.j  ava2 s.c om*/
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.Collection;

public class Main {
    /** 
     * Creates a backslash escaped string, joining all the items. 
     * @see #escapeTextWithSeparator
     */
    public static String join(Collection<?> items, char separator) {
        if (items == null)
            return "";
        StringBuilder sb = new StringBuilder(items.size() << 3);
        boolean first = true;
        for (Object o : items) {
            String item = String.valueOf(o);
            if (first) {
                first = false;
            } else {
                sb.append(separator);
            }
            appendEscapedTextToBuilder(sb, item, separator);
        }
        return sb.toString();
    }

    /**
     * writes chars from item to out, backslash escaping as needed based on separator -- 
     * but does not append the seperator itself
     */
    public static void appendEscapedTextToBuilder(StringBuilder out, String item, char separator) {
        for (int i = 0; i < item.length(); i++) {
            char ch = item.charAt(i);
            if (ch == '\\' || ch == separator) {
                out.append('\\');
            }
            out.append(ch);
        }
    }
}

Related

1. join(Collection collection, String separator)
2. join(Collection collection, String separator)
3. join(Collection collection, String separator)
4. join(Collection collection, String separatorString)
5. join(Collection elements, String separator)
6. join(Collection items, String delim)
7. join(Collection items, String delimiter)
8. join(Collection iterable, String delimiter)
9. join(Collection objects, String token, StringBuilder buf)