stringutility.java

本源码为教学管理信息系统

package com.wygl.xmlhttp;

/**
 * 字符串工具类，根据用户提供的原始字符集和目标字符集，将字符串转换成目标字符集的字符串
 * <p>Title:StringUtility </p>
 * <p>Description:字符串工具类  </p>
 * <p>Copyright: Copyright (c) 2004</p>
 * @version 1.0
 */

public class StringUtility { 
  	/**
   * 转码方法
   * @param plainText String 需要转码的字符串
   * @throws Exception
   * @return String
   */
  	private static String encode(String plainText) throws Exception {
	  	if (plainText==null){
	  		return "";
	  	}
	  	String s = "";	  	
    	StringBuffer encodedText = new StringBuffer();
        for(int i = 0; i < plainText.length(); i++){
            int iChar = plainText.charAt(i);
            if(iChar > 255){
                s = Integer.toString(iChar, 16);
                for(int j = s.length(); j < 4; j++)
                    s = "0" + s;
                encodedText.append("#" + s);
            } else if(iChar < 48 || iChar > 57 && iChar < 65 || iChar > 90 && iChar < 97 || iChar > 122){
                s = Integer.toString(iChar, 16);
                for(int j = s.length(); j < 2; j++)
                    s = "0" + s;
                encodedText.append("~" + s);
            } else {
                encodedText.append(plainText.charAt(i));
            }
        }
        return encodedText.toString(); 
  	}
  	/**
   * 解码方法
   * @param encodedText String 需要解码的字符串
   * @throws Exception
   * @return String
   */
	private static String decode(String encodedText) throws Exception {
        if(encodedText == null)
            return "";
        String s = "";
        StringBuffer plainText = new StringBuffer();
        for(int i = 0; i < encodedText.length(); i++){
            char c = encodedText.charAt(i);
            switch(c) {
	            case 126: // '~'
	                s = encodedText.substring(i + 1, i + 3);
	                plainText.append((char)Integer.parseInt(s, 16));
	                i += 2;
	                break;
	
	            case 35: // '#'
	                s = encodedText.substring(i + 1, i + 5);
	                plainText.append((char)Integer.parseInt(s, 16));
	                i += 4;
	                break;
	
	            default:
	                plainText.append(c);
	                break;
            }
        }
        return plainText.toString();
    } 
	/**
   * 获得转码方法
   * @param str String 需要转码的字符串
   * @throws Exception
   * @return String
   */ 
	public static String getEncodeStr(String str) throws Exception{
		try {
			return encode(str);
		} catch (Exception e) {
			throw new Exception("转码出错,"+e.getMessage());
		} 
	} 
	 /**
   * 获得解码方法
   * @param str String 需要解码的字符串
   * @throws Exception
   * @return String
   */  
	 public static String getDecodeStr(String str) throws Exception{
		try {
			return decode(str);
		} catch (Exception e) {
			throw new Exception("反转码出错,"+e.getMessage());
		} 
	} 	
}