Java ME平台中的URLEncoder实现类

Java ME平台中的URLEncoder实现类2007-05-30 j2medev 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 <CODE>application/x-www-form-urlencoded</CODE> MIME
* format. For more information about HTML form encoding, consult the HTML
* <A HREF="http：//www.w3.org/TR/html4/">specification</A>.
*
* 
* When encoding a String, the following rules apply:
*
* 
* <ul>
* <li>The alphanumeric characters "<code>a</code>" through
* "<code>z</code>", "<code>A</code>" through
* "<code>Z</code>" and "<code>0</code>"
* through "<code>9</code>" remain the same.
* <li>The special characters "<code>.</code>",
* "<code>-</code>", "<code>*</code>", and
* "<code>_</code>" remain the same.
* <li>The space character "<code> </code>" is
* converted into a plus sign "<code>+</code>".
* <li>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
* "<code>%xy</code>", 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.
* </ul>
*
* 
* 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（） { }