环绕路径，确保路径以“/”开头，以“/”结尾。

/*

 * ? Copyright IBM Corp. 2012-2013

 * 

 * 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.

 */

//package com.nowjava;
/*n o w j a   v  a . c o m - 时  代  Java 提 供*/

public class Main {

    /**

     * Surrounds a path, ensuring that it starts with a '/' and ends with a '/'.

     * @ibm-api

     */

    public static String surroundPath(String path, char sep) {

        boolean needLeadingSlash = path.charAt(0) != sep;

        boolean needTrailingSlash = path.charAt(path.length() - 1) != sep;

        if (needLeadingSlash || needTrailingSlash) {

            if (needLeadingSlash && needTrailingSlash) {

                StringBuilder b = new StringBuilder();

                b.append(sep);

                b.append(path);

                b.append(sep);

                return b.toString();

            } else if (needLeadingSlash) {

                StringBuilder b = new StringBuilder();

                b.append(sep);

                b.append(path);

                return b.toString();

            } else {