使用URI中允许的字符集对字符串进行编码。

/**

 * Copyright (c) 2000-2016 Liferay, Inc. All rights reserved.

 *

 * 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;
/**来自 
 NowJava.com - 时  代  Java**/


import java.io.UnsupportedEncodingException;


public class Main {

    private static final boolean[] sValidChar = new boolean[128];

    private static final char[] sHexLookup = new char[16];


    /**

     * Encodes a String using the set of characters allowed in a URI. This method encodes a multibyte string in UTF8

     *

     * @param   value  <code>String</code> to be translated.

     *

     * @return  the translated <code>String</code>.

     */

    public static String encodeUTF(String value) {

        String encodedValue = null;


        try {

            encodedValue = encode(value, "UTF8");

        } catch (UnsupportedEncodingException e) {

            // TODO - error handling

            // should never happen for this method because the

            // character encoding is constant//来自 n o w j a v a . c o m - 时代Java

        }


        return encodedValue;

    }


    /**

     * Encodes a String using the set of characters allowed in a URI.

     *

     * @param      value     <code>String</code> to be translated.

     * @param      encoding  the Java alias for the character encoding to be used to convert non-ASCII characters into

     *                       bytes (e.g. <code>"UTF8"</code>).

     *

     * @return     the translated <code>String</code>.

     *

     * @exception  UnsupportedEncodingException  if the given encoding is not a recognised character encoding.

     */

    public static String encode(String value, String encoding)

            throws UnsupportedEncodingException {


        // Create a buffer that is roughly 1.5 times bigger than the value to

        // account for possible expansion of the resulting encoded string

        int len = value.length();

        StringBuilder out = new StringBuilder(len * 3 / 2);


        for (int charIndex = 0; charIndex < len; charIndex++) {

            char aChar = value.charAt(charIndex);


            if ((aChar <= 127) && sValidChar[aChar]) {

                out.append(aChar);

            } else if (aChar == ' ') {

                out.append('+');

            } else {

                byte[] charBytes = String.valueOf(aChar).getBytes(encoding);


                // For each byte to encode this character, write a '%',