常用java字符串操作函数，java字符串函数,/** * 分割字符

常用java字符串操作函数，java字符串函数,/** * 分割字符

/**   * 分割字符串   *   * @param str String 原始字符串   * @param splitsign String 分隔符   * @return String[] 分割后的字符串数组   */@SuppressWarnings("unchecked")public static String[] split(String str, String splitsign) {    int index;    if (str == null || splitsign == null)      return null;    ArrayList al = new ArrayList();    while ((index = str.indexOf(splitsign)) != -1) {      al.add(str.substring(0, index));      str = str.substring(index + splitsign.length());    }    al.add(str);    return (String[]) al.toArray(new String[0]);}/**   * 替换字符串   *   * @param from String 原始字符串   * @param to String 目标字符串   * @param source String 母字符串   * @return String 替换后的字符串   */public static String replace(String from, String to, String source) {    if (source == null || from == null || to == null)      return null;    StringBuffer bf = new StringBuffer("");    int index = -1;    while ((index = source.indexOf(from)) != -1) {      bf.append(source.substring(0, index) + to);      source = source.substring(index + from.length());      index = source.indexOf(from);    }    bf.append(source);    return bf.toString();}/**   * 替换字符串，能能够在HTML页面上直接显示(替换双引号和小于号)   *   * @param str String 原始字符串   * @return String 替换后的字符串   */public static String htmlencode(String str) {    if (str == null) {      return null;    }    return replace("\\"", "&amp;quot;", replace("<", "&amp;lt;", str));}/**   * 替换字符串，将被编码的转换成原始码（替换成双引号和小于号）   *   * @param str String   * @return String   */public static String htmldecode(String str) {    if (str == null) {      return null;    }    return replace("&amp;quot;", "\\"", replace("&amp;lt;", "<", str));}private static final String _BR = "<br/>";/**   * 在页面上直接显示文本内容，替换小于号，空格，回车，TAB   *   * @param str String 原始字符串   * @return String 替换后的字符串   */public static String htmlshow(String str) {    if (str == null) {      return null;    }    str = replace("<", "&amp;lt;", str);    str = replace(" ", "&amp;nbsp;", str);    str = replace("\\r\\n", _BR, str);    str = replace("\\n", _BR, str);    str = replace("\\t", "&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;", str);    return str;}/**   * 返回指定字节长度的字符串   *   * @param str String 字符串   * @param length int 指定长度   * @return String 返回的字符串   */public static String toLength(String str, int length) {    if (str == null) {      return null;    }    if (length <= 0) {      return "";    }    try {      if (str.getBytes("GBK").length <= length) {        return str;      }    } catch (Exception ex) {    }    StringBuffer buff = new StringBuffer();    int index = 0;    char c;    length -= 3;    while (length > 0) {      c = str.charAt(index);      if (c < 128) {        length--;      } else {        length--;        length--;      }      buff.append(c);      index++;    }    buff.append("...");    return buff.toString();}/**   * 判断是否为整数   *   * @param str 传入的字符串   * @return 是整数返回true,否则返回false   */public static boolean isInteger(String str) {    Pattern pattern = Pattern.compile("^[-\\\\+]?[\\\\d]*$");    return pattern.matcher(str).matches();}/**   * 判断是否为浮点数，包括double和float   *   * @param str 传入的字符串   * @return 是浮点数返回true,否则返回false   */public static boolean isDouble(String str) {    Pattern pattern = Pattern.compile("^[-\\\\+]?[.\\\\d]*$");    return pattern.matcher(str).matches();}/**   * 判断输入的字符串是否符合Email样式.   *   * @param str 传入的字符串   * @return 是Email样式返回true,否则返回false   */public static boolean isEmail(String str) {    Pattern pattern = Pattern.compile("^\\\\w+([-+.]\\\\w+)*@\\\\w+([-.]\\\\w+)*\\\\.\\\\w+([-.]\\\\w+)*$");    return pattern.matcher(str).matches();}/**   * 判断输入的字符串是否为纯汉字   *   * @param str 传入的字符窜   * @return 如果是纯汉字返回true,否则返回false   */public static boolean isChinese(String str) {    Pattern pattern = Pattern.compile("[\\u0391-\\uFFE5]+$");    return pattern.matcher(str).matches();}/**   * 是否为空白,包括null和""   *   * @param str   * @return   */public static boolean isBlank(String str) {    return str == null || str.trim().length() == 0;}/*** 判断是不是合法手机* handset 手机号码*/public static boolean isHandset(String handset) {try {   if(!handset.substring(0,1).equals("1")) {    return false;   }   if (handset==null || handset.length()!=11) {    return false;   }   String check = "^[0123456789]+$";   Pattern regex = Pattern.compile(check);   Matcher matcher = regex.matcher(handset);   boolean isMatched = matcher.matches();   if(isMatched) {    return true;   } else {    return false;   }} catch (RuntimeException e) {   return false;}}}