stringutils.java
来自「开源项目openfire的完整源程序」· Java 代码 · 共 2,677 行 · 第 1/5 页
JAVA
2,677 行
if (i > last) {
out.append(input, last, i - last);
}
last = i + 1;
out.append(LT_ENCODE);
}
else if (ch == '>') {
if (i > last) {
out.append(input, last, i - last);
}
last = i + 1;
out.append(GT_ENCODE);
}
else if (ch == '"') {
if (i > last) {
out.append(input, last, i - last);
}
last = i + 1;
out.append(QUOTE_ENCODE);
}
}
if (last == 0) {
return in;
}
if (i > last) {
out.append(input, last, i - last);
}
return out.toString();
}
/**
* Used by the hash method.
*/
private static MessageDigest digest = null;
/**
* Hashes a String using the Md5 algorithm and returns the result as a
* <p/>
* String of hexadecimal numbers. This method is synchronized to avoid
* <p/>
* excessive MessageDigest object creation. If calling this method becomes
* <p/>
* a bottleneck in your code, you may wish to maintain a pool of
* <p/>
* MessageDigest objects instead of using this method.
* <p/>
* <p/>
* <p/>
* A hash is a one-way function -- that is, given an
* <p/>
* input, an output is easily computed. However, given the output, the
* <p/>
* input is almost impossible to compute. This is useful for passwords
* <p/>
* since we can store the hash and a hacker will then have a very hard time
* <p/>
* determining the original password.
* <p/>
* <p/>
* <p/>
* In Jive, every time a user logs in, we simply
* <p/>
* take their plain text password, compute the hash, and compare the
* <p/>
* generated hash to the stored hash. Since it is almost impossible that
* <p/>
* two passwords will generate the same hash, we know if the user gave us
* <p/>
* the correct password or not. The only negative to this system is that
* <p/>
* password recovery is basically impossible. Therefore, a reset password
* <p/>
* method is used instead.
*
* @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) {
}
}
// Now, compute hash.
try {
digest.update(data.getBytes("utf-8"));
}
catch (UnsupportedEncodingException e) {
}
return encodeHex(digest.digest());
}
public synchronized static final String hash(byte[] data) {
if (digest == null) {
try {
digest = MessageDigest.getInstance("MD5");
}
catch (NoSuchAlgorithmException nsae) {
}
}
// Now, compute hash.
digest.update(data);
return encodeHex(digest.digest());
}
/**
* Turns an array of bytes into a String representing each byte as an
* <p/>
* unsigned hex number.
* <p/>
* <p/>
* <p/>
* Method by Santeri Paavolainen, Helsinki Finland 1996<br>
* <p/>
* (c) Santeri Paavolainen, Helsinki Finland 1996<br>
* <p/>
* 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();
}
/**
* Turns a hex encoded string into a byte array. It is specifically meant
* <p/>
* 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) {
int newByte = 0x00;
newByte |= hexCharToByte(chars[i]);
newByte <<= 4;
newByte |= hexCharToByte(chars[i + 1]);
bytes[byteCount] = (byte)newByte;
byteCount++;
}
return bytes;
}
/**
* Returns the the byte value of a hexadecmical char (0-f). It's assumed
* <p/>
* 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.
//*********************************************************************
/**
* Encodes a String as a base64 String.
*
* @param data a String to encode.
* @return a base64 encoded String.
*/
public static String encodeBase64(String data) {
byte [] bytes = null;
try {
bytes = data.getBytes("ISO-8859-1");
}
catch (UnsupportedEncodingException uee) {
}
return encodeBase64(bytes);
}
/**
* 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();
}
/**
* Decodes a base64 String.
*
* @param data a base64 encoded String to decode.
* @return the decoded String.
*/
public static String decodeBase64(String data) {
byte [] bytes = null;
try {
bytes = data.getBytes("ISO-8859-1");
}
catch (UnsupportedEncodingException uee) {
}
return decodeBase64(bytes);
}
/**
* 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(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(c1);
c = ((c << 6) & 0xc0) | c1;
ret.append((char)c);
}
}
return ret.toString();
}
/**
* The method below is under the following license
* <p/>
* <p/>
* <p/>
* ====================================================================
* <p/>
* <p/>
* <p/>
* The Apache Software License, Version 1.1
* <p/>
* <p/>
⌨️ 快捷键说明
复制代码Ctrl + C
搜索代码Ctrl + F
全屏模式F11
增大字号Ctrl + =
减小字号Ctrl + -
显示快捷键?