字符编码工具类
字符编码工具类
package charTools;import java.io.UnsupportedEncodingException;import java.net.URLEncoder;import java.net.URLDecoder;import java.security.*;import java.text.*;import java.util.*;/** * Title:字符编码工具类 * Description: * Copyright: flashman.com.cn Copyright (c) 2005 * Company: flashman.com.cn * @author: jeffzhu * @version 1.0 *//* *===================功能说明==================================== * *================================字符操作======================= *String chopAtWord(String string, int length) 从字符串第一位开始取n位字符 * * * *=================================编码转换====================== *String ISO2GB(String text) 转换编码 ISO-8859-1到GB2312 *String GB2ISO(String text) 转换编码 GB2312到ISO-8859-1 *String Utf8URLencode(String text) Utf8URL编码 *String Utf8URLdecode(String text) Utf8URL解码 *String CodeToWord(String text） utf8URL编码转字符 *boolean Utf8codeCheck(String text) 编码是否有效 *boolean isUtf8Url(String text) 是否Utf8Url编码 * * *==================================加密解密====================== *synchronized static final String hash(String data) MessageDigest加密 *String encodeBase64(String data) base64加密 *public static String decodeBase64(String data) base64解密 * * */public class charTools1 {/** * 转换编码 ISO-8859-1到GB2312 * @param text * @return */ public String ISO2GB(String text) { String result = ""; try { result = new String(text.getBytes("ISO-8859-1"), "GB2312"); } catch (UnsupportedEncodingException ex) { result = ex.toString(); } return result; } /** * 转换编码 GB2312到ISO-8859-1 * @param text * @return */ public String GB2ISO(String text) { String result = ""; try { result = new String(text.getBytes("GB2312"), "ISO-8859-1"); } catch (UnsupportedEncodingException ex) { ex.printStackTrace(); } return result; } /** * Utf8URL编码 * @param s * @return */ public String Utf8URLencode(String text) { StringBuffer result = new StringBuffer(); for (int i = 0; i < text.length(); i++) { char c = text.charAt(i); if (c >= 0 && c <= 255) { result.append(c); }else { byte[] b = new byte[0]; try { b = Character.toString(c).getBytes("UTF-8"); }catch (Exception ex) { } for (int j = 0; j < b.length; j++) { int k = b[j]; if (k < 0) k += 256; result.append("%" + Integer.toHexString(k).toUpperCase()); } } } return result.toString(); } /** * Utf8URL解码 * @param text * @return */ public String Utf8URLdecode(String text) { String result = ""; int p = 0; if (text!=null && text.length()>0){ text = text.toLowerCase(); p = text.indexOf("%e"); if (p == -1) return text; while (p != -1) { result += text.substring(0, p); text = text.substring(p, text.length()); if (text == "" || text.length() < 9) return result; result += CodeToWord(text.substring(0, 9)); text = text.substring(9, text.length()); p = text.indexOf("%e"); } } return result + text; } /** * utf8URL编码转字符 * @param text * @return */ private String CodeToWord(String text) { String result; if (Utf8codeCheck(text)) { byte[] code = new byte[3]; code[0] = (byte) (Integer.parseInt(text.substring(1, 3), 16) - 256); code[1] = (byte) (Integer.parseInt(text.substring(4, 6), 16) - 256); code[2] = (byte) (Integer.parseInt(text.substring(7, 9), 16) - 256); try { result = new String(code, "UTF-8"); }catch (UnsupportedEncodingException ex) { result = null; } } else { result = text; } return result; } public static boolean isValidUtf8(byte[] b, int aMaxCount) { int lLen = b.length, lCharCount = 0; for (int i = 0; i < lLen && lCharCount < aMaxCount; ++lCharCount) { byte lByte = b[i++]; //to fast operation, ++ now, ready for the following for(;;) if (lByte >= 0) continue; //>=0 is normal ascii if (lByte < (byte) 0xc0 || lByte > (byte) 0xfd) return false; int lCount = lByte > (byte) 0xfc ? 5 : lByte > (byte) 0xf8 ? 4 : lByte > (byte) 0xf0 ? 3 : lByte > (byte) 0xe0 ? 2 : 1; if (i + lCount > lLen) return false; for (int j = 0; j < lCount; ++j, ++i) if (b[i] >= (byte) 0xc0)return false; } return true; } /** * 编码是否有效 * @param text * @return */ private boolean Utf8codeCheck(String text){ String sign = ""; if (text.startsWith("%e")) for (int i = 0, p = 0; p != -1; i++) { p = text.indexOf("%", p); if (p != -1) p++; sign += p; } return sign.equals("147-1"); } /** * 是否Utf8Url编码 * @param text * @return */ public boolean isUtf8Url(String text) { text = text.toLowerCase(); int p = text.indexOf("%"); if (p != -1 && text.length() - p > 9) { text = text.substring(p, p + 9); } return Utf8codeCheck(text); } /* * ======================================加密解密================================================= */ /** * Used by the hash method. */ private static MessageDigest digest = null; /** * 将传入的参数转化为它所对应的hash码 * @param data the String to compute the hash of. * @return a hashed version of the passed-in String */ public synchronized static final String hash(String data) { if (digest == null) { try { digest = MessageDigest.getInstance("MD5"); } catch (NoSuchAlgorithmException nsae) { System.err.println("Failed to load the MD5 MessageDigest. " + "Jive will be unable to function normally."); nsae.printStackTrace(); } } // Now, compute hash. digest.update(data.getBytes()); return encodeHex(digest.digest()); } /** * 将传入的byte型数组转化为对应的十六进制，并组合成字符串输出 * Turns an array of bytes into a String representing each byte as an * unsigned hex number. * <p> * Method by Santeri Paavolainen, Helsinki Finland 1996<br> * (c) Santeri Paavolainen, Helsinki Finland 1996<br> * Distributed under LGPL. * * @param bytes an array of bytes to convert to a hex-string * @return generated hex string */ public static final String encodeHex(byte[] bytes) { StringBuffer buf = new StringBuffer(bytes.length * 2); int i; for (i = 0; i < bytes.length; i++) { if (((int) bytes[i] & 0xff) < 0x10) { buf.append("0"); } buf.append(Long.toString((int) bytes[i] & 0xff, 16)); } return buf.toString(); } /** * 将十六进制数字型的字符串转化为byte型的数组，将字符串按两位两位分开 * Turns a hex encoded string into a byte array. It is specifically meant * to "reverse" the toHex(byte[]) method. * @param hex a hex encoded String to transform into a byte array. * @return a byte array representing the hex String[ */ public static final byte[] decodeHex(String hex) { char [] chars = hex.toCharArray(); byte[] bytes = new byte[chars.length/2]; int byteCount = 0; for (int i=0; i<chars.length; i+=2) { byte newByte = 0x00; newByte |= hexCharToByte(chars[i]); newByte <<= 4; newByte |= hexCharToByte(chars[i+1]); bytes[byteCount] = newByte; byteCount++; } return bytes; } /** * Returns the the byte value of a hexadecmical char (0-f). It's assumed * that the hexidecimal chars are lower case as appropriate. * * @param ch a hexedicmal character (0-f) * @return the byte value of the character (0x00-0x0F) */ private static final byte hexCharToByte(char ch) { switch(ch) { case '0': return 0x00; case '1': return 0x01; case '2': return 0x02; case '3': return 0x03; case '4': return 0x04; case '5': return 0x05; case '6': return 0x06; case '7': return 0x07; case '8': return 0x08; case '9': return 0x09; case 'a': return 0x0A; case 'b': return 0x0B; case 'c': return 0x0C; case 'd': return 0x0D; case 'e': return 0x0E; case 'f': return 0x0F; } return 0x00; } //********************************************************************* //* Base64 - a simple base64 encoder and decoder. //* //* Copyright (c) 1999, Bob Withers - bwit@pobox.com //* //* This code may be freely used for any purpose, either personal //* or commercial, provided the authors copyright notice remains //* intact. //********************************************************************* /**base64加密 * Encodes a String as a base64 String. * * @param data a String to encode. * @return a base64 encoded String. */ public static String encodeBase64(String data) { return encodeBase64(data.getBytes()); } /** * Encodes a byte array into a base64 String. * * @param data a byte array to encode. * @return a base64 encode String. */ public static String encodeBase64(byte[] data) { int c; int len = data.length; StringBuffer ret = new StringBuffer(((len / 3) + 1) * 4); for (int i = 0; i < len; ++i) { c = (data[i] >> 2) & 0x3f; ret.append(cvt.charAt(c)); c = (data[i] << 4) & 0x3f; if (++i < len) c |= (data[i] >> 4) & 0x0f; ret.append(cvt.charAt(c)); if (i < len) { c = (data[i] << 2) & 0x3f; if (++i < len) c |= (data[i] >> 6) & 0x03; ret.append(cvt.charAt(c)); } else { ++i; ret.append((char) fillchar); } if (i < len) { c = data[i] & 0x3f; ret.append(cvt.charAt(c)); } else { ret.append((char) fillchar); } } return ret.toString(); } /**base64解密 * Decodes a base64 String. * * @param data a base64 encoded String to decode. * @return the decoded String. */ public static String decodeBase64(String data) { return decodeBase64(data.getBytes()); } /** * Decodes a base64 aray of bytes. * * @param data a base64 encode byte array to decode. * @return the decoded String. */ public static String decodeBase64(byte[] data) { int c, c1; int len = data.length; StringBuffer ret = new StringBuffer((len * 3) / 4); for (int i = 0; i < len; ++i) { c = cvt.indexOf(data[i]); ++i; c1 = cvt.indexOf(data[i]); c = ((c << 2) | ((c1 >> 4) & 0x3)); ret.append((char) c); if (++i < len) { c = data[i]; if (fillchar == c) break; c = cvt.indexOf((char) c); c1 = ((c1 << 4) & 0xf0) | ((c >> 2) & 0xf); ret.append((char) c1); } if (++i < len) { c1 = data[i]; if (fillchar == c1) break; c1 = cvt.indexOf((char) c1); c = ((c << 6) & 0xc0) | c1; ret.append((char) c); } } return ret.toString(); } private static final int fillchar = '='; private static final String cvt = "ABCDEFGHIJKLMNOPQRSTUVWXYZ" + "abcdefghijklmnopqrstuvwxyz" + "0123456789+/"; /** * 从字符串中取n位字符 * * @param string the String to chop. * @param length the index in <code>string</code> to start looking for a * whitespace boundary at. * @return a substring of <code>string</code> whose length is less than or * equal to <code>length</code>, and that is chopped at whitespace. */ public static final String chopAtWord(String string, int length) { if (string == null) { return string; } char [] charArray = string.toCharArray(); int sLength = string.length(); if (length < sLength) { sLength = length; } // First check if there is a newline character before length; if so, // chop word there. for (int i=0; i<sLength-1; i++) { // Windows if (charArray[i] == '\r' && charArray[i+1] == '\n') { return string.substring(0, i+1); } // Unix else if (charArray[i] == '\n') { return string.substring(0, i); } } // Also check boundary case of Unix newline if (charArray[sLength-1] == '\n') { return string.substring(0, sLength-1); } // Done checking for newline, now see if the total string is less than // the specified chop point. if (string.length() < length) { return string; } // No newline, so chop at the first whitespace. for (int i = length-1; i > 0; i--) { if (charArray[i] == ' ') { return string.substring(0, i).trim(); } } // Did not find word boundary so return original String chopped at // specified length. return string.substring(0, length); } /** * 测试 * @param args */ public static void main(String[] args) { //实例化工具类 charTools1 charTools = new charTools1(); String url; //定义一个URL字符串 url="http://www.baidu.com/s?bs=indexof+%D3%C3%B7%A8&f=8&wd=java+%D7%D6%B7%FB%B4%A6%C0%ED%B9%A4%BE%DF%C0%E0";// url = "http://www.google.com/search?hl=zh-CN&newwindow=1&q=%E4%B8%AD%E5%9B%BD%E5%A4%A7%E7%99%BE%E7%A7%91%E5%9C%A8%E7%BA%BF%E5%85%A8%E6%96%87%E6%A3%80%E7%B4%A2&btnG=%E6%90%9C%E7%B4%A2&lr="; //调用方法isUtf8Url，进行判断是否Utf8Url编码 if(charTools.isUtf8Url(url)){ //如果是Utf8Url编码则调用Utf8URLdecode进行解码 System.out.println(charTools.Utf8URLdecode(url)); }else{ System.out.println(URLDecoder.decode(url)); } url = "http://www.baidu.com/baidu?word=%D6%D0%B9%FA%B4%F3%B0%D9%BF%C6%D4%DA%CF%DF%C8%AB%CE%C4%BC%EC%CB%F7&tn=myie2dg"; if(charTools.isUtf8Url(url)){ System.out.println(charTools.Utf8URLdecode(url)); }else{ System.out.println(URLDecoder.decode(url)); } String charT="刘奇庭是不错的人"; String ct=charTools1.chopAtWord(charT, 5); System.out.println(ct); }}