Java ME平台中的URLEncoder实现类
这个类是从java.net.URLEncoder修改来的 经测试能够正常完成URL编码的工作，在几部手机上测试过。使用的时候直接调用URLEncoder.encode("中国")即可 如果向服务器端发送。可以使用如下的办法对中文进行编码，然后发送向服务器。

String data = "para="+URLEncoder.encode("参数");

outputStream.write(data.getBytes());

.......

在服务器端 以servlet为例 request.getParameter("para")即可获得“参数”

package com.j2medev.httpme.tools;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.UnsupportedEncodingException;
/**
* Utility class for form encoding.this class is modified form java.net.URLEncoder so that it can work well in cldc env.
* This class contains static methods
* for converting a String to the application/x-www-form-urlencoded MIME
* format. For more information about HTML form encoding, consult the HTML
* specification.
*
*

* When encoding a String, the following rules apply:
*
*

*

*
• The alphanumeric characters "a" through
  * "z", "A" through
  * "Z" and "0"
  * through "9" remain the same.
  *
• The special characters ".",
  * "-", "*", and
  * "_" remain the same.
  *
• The space character " " is
  * converted into a plus sign "+".
  *
• All other characters are unsafe and are first converted into
  * one or more bytes using some encoding scheme. Then each byte is
  * represented by the 3-character string
  * "%xy", where xy is the
  * two-digit hexadecimal representation of the byte.
  * The recommended encoding scheme to use is UTF-8. However,
  * for compatibility reasons, if an encoding is not specified,
  * then the default encoding of the platform is used.
  *

*
*

* For example using UTF-8 as the encoding scheme the string "The
* string ü@foo-bar" would get converted to
* "The+string+%C3%BC%40foo-bar" because in UTF-8 the character
* ü is encoded as two bytes C3 (hex) and BC (hex), and the
* character @ is encoded as one byte 40 (hex).
*
* @author mingjava
* @version 0.1 05/06/2006
* @since httpme 0.1
*/
public class URLEncoder {

/** The characters which do not need to be encoded. */
private static boolean[] dontNeedEncoding;
private static String defaultEncName = "";
static final int caseDiff = ('a' - 'A');
static {
dontNeedEncoding = new boolean[256];
int i;
for (i = 'a'; i <= 'z'; i++) {
dontNeedEncoding[i] = true;
}
for (i = 'A'; i <= 'Z'; i++) {
dontNeedEncoding[i] = true;
}
for (i = '0'; i <= '9'; i++) {
dontNeedEncoding[i] = true;
}
dontNeedEncoding[' '] = true; // encoding a space to a + is done in the encode() method
dontNeedEncoding['-'] = true;
dontNeedEncoding['_'] = true;
dontNeedEncoding['.'] = true;
dontNeedEncoding['*'] = true;
defaultEncName = System.getProperty("microedition.encoding");
if(defaultEncName == null || defaultEncName.trim().length() == 0){
defaultEncName = "UTF-8";
}
}

public static final int MIN_RADIX = 2;

/**
* The maximum radix available for conversion to and from strings.
*/
public static final int MAX_RADIX = 36;
/**
* The class is not meant to be instantiated.
*/
private URLEncoder() { }