stringutil.java

一个JSP的登陆管理系统

package test.util;

import java.util.List;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.StringTokenizer;

/**
 * String Util.
 * @version 0.3.5
 * @author Xiaobo Liu
 */
public class StringUtil{

  public static List quoteStrList(List list) {
    List tmpList = list;
    list = new ArrayList();
    Iterator i = tmpList.iterator();
    while (i.hasNext()) {
      String str = (String) i.next();
      str = "'" + str + "'";
      list.add(str);
    }
    return list;
  }

  public static String join(List list, String delim) {
    if (list == null || list.size() < 1)
      return null;
    StringBuffer buf = new StringBuffer();
    Iterator i = list.iterator();
    while (i.hasNext()) {
      buf.append((String) i.next());
      if (i.hasNext())
        buf.append(delim);
    }
    return buf.toString();
  }

  public static List split(String str, String delim) {
    List splitList = null;
    StringTokenizer st = null;

    if (str == null)
      return splitList;

    if (delim != null)
      st = new StringTokenizer(str, delim);
    else
      st = new StringTokenizer(str);

    if (st != null && st.hasMoreTokens()) {
      splitList = new ArrayList();

      while (st.hasMoreTokens())
        splitList.add(st.nextToken());
    }
    return splitList;
  }
  public static String createBreaks(String input, int maxLength) {
      char chars[] = input.toCharArray();
      int len = chars.length;
      StringBuffer buf = new StringBuffer(len);
      int count = 0;
      int cur = 0;
      for(int i = 0; i < len; i++){
          if(Character.isWhitespace(chars[i]))
              count = 0;
          if(count >= maxLength)
          {
              count = 0;
              buf.append(chars, cur, i - cur).append(" ");
              cur = i;
          }
          count++;
      }
      buf.append(chars, cur, len - cur);
      return buf.toString();
  }
  /**
   * Escape SQL tags, ' to ''; \ to \\.
   * @param input string to replace
   * @return string
   */
  public static String escapeSQLTags(String input)
  {
    if(input == null || input.length() == 0)
      return input;
    StringBuffer buf = new StringBuffer();
    char ch = ' ';
    for(int i = 0; i < input.length(); i++)  {
      ch = input.charAt(i);
      if(ch == '\\')
        buf.append("\\\\");
      else if(ch == '\'')
        buf.append("\'\'");
      else
        buf.append(ch);
    }
    return buf.toString();
  }
  /**
   * Escape HTML tags.
   * @param input string to replace
   * @return string
   */
  public static String escapeHTMLTags(String input){
    if(input == null || input.length() == 0)
      return input;
    StringBuffer buf = new StringBuffer();
    char ch = ' ';
    for(int i = 0; i < input.length(); i++)  {
      ch = input.charAt(i);
      if(ch == '<')
        buf.append("&lt;");
      else if(ch == '>')
        buf.append("&gt;");
      else if(ch == '&')
        buf.append("&amp;");
      else if(ch == '"')
        buf.append("&quot;");
      else
        buf.append(ch);
    }
    return buf.toString();
  }
  /**
   * Convert new lines, \n or \r\n to <BR />.
   * @param input string to convert
   * @return string
   */
  public static String convertNewlines(String input)
  {
    input = replace(input, "\r\n", "\n");
    input = replace(input, "\n", "<BR />");
    return input;
  }

  public static String replace(String mainString, String oldString, String newString) {
    if (mainString == null)
      return null;
    int i = mainString.lastIndexOf(oldString);
    if (i < 0)
      return mainString;
    StringBuffer mainSb = new StringBuffer(mainString);
    while (i >= 0) {
      mainSb.replace(i, i + oldString.length(), newString);
      i = mainString.lastIndexOf(oldString, i - 1);
    }
    return mainSb.toString();
  }
  /**
   * Check a string null or blank.
   * @param param string to check
   * @return boolean
   */
  public  static boolean nullOrBlank(String param){
    return (param==null||param.trim().equals(""))?true:false;
  }
  public  static String notNull(String param){
    return param==null?"":param.trim();
  }
  /**
   * Parse a string to int.
   * @param param string to parse
   * @return int value, on exception return 0.
   */

  public  static int parseInt(String param) {
    int i = 0;
    try {
      i = Integer.parseInt(param);
    } catch (Exception e) {
      i = (int)parseFloat(param);
    }
    return i;
  }
  public  static long parseLong(String param) {
    long l = 0;
    try {
      l = Long.parseLong(param);
    } catch (Exception e) {
      l = (long)parseDouble(param);
    }
    return l;
  }
  public  static float parseFloat(String param) {
    float f = 0;
    try {
      f = Float.parseFloat(param);
    } catch (Exception e) {
      //
    }
    return f;
  }
  public  static double parseDouble(String param) {
    double d = 0;
    try {
      d = Double.parseDouble(param);
    } catch (Exception e) {
      //
    }
    return d;
  }
  /**
   * Parse a string to boolean.
   * @param param string to parse
   * @return boolean value, if param begin with(1,y,Y,t,T) return true,
   * on exception return false.
   */
  public  static boolean parseBoolean(String param) {
    if (nullOrBlank(param))
      return false;
    switch (param.charAt(0)) {
      case '1':
      case 'y':
      case 'Y':
      case 't':
      case 'T' :
        return true;
    }
    return false;
  }
  /**
   * Convert URL .
   * @param input string to convert
   * @return string
   */
  public static String convertURL(String input)   {
      if(input == null || input.length() == 0)
          return input;
      StringBuffer buf = new StringBuffer(input.length() + 25);
      char chars[] = input.toCharArray();
      int len = input.length();
      int index = -1;
      int i = 0;
      int j = 0;
      int oldend = 0;
      while(++index < len)
      {
          char cur = chars[i = index];
          j = -1;
          if((cur == 'f' && index < len - 6 && chars[++i] == 't' && chars[++i] == 'p' || cur == 'h' && (i = index) < len - 7 && chars[++i] == 't' && chars[++i] == 't' && chars[++i] == 'p' && (chars[++i] == 's' || chars[--i] == 'p')) && i < len - 4 && chars[++i] == ':' && chars[++i] == '/' && chars[++i] == '/')
              j = ++i;
          if(j > 0)
          {
              if(index == 0 || (cur = chars[index - 1]) != '\'' && cur != '"' && cur != '<' && cur != '=')
              {
                  cur = chars[j];
                  while(j < len)
                  {
                      if(cur == ' ' || cur == '\t' || cur == '\'' || cur == '"' || cur == '<' || cur == '[' || cur == '\n' || cur == '\r' && j < len - 1 && chars[j + 1] == '\n')
                          break;
                      if(++j < len)
                          cur = chars[j];
                  }
                  cur = chars[j - 1];
                  if(cur == '.' || cur == ',' || cur == ')' || cur == ']')
                      j--;
                  buf.append(chars, oldend, index - oldend);
                  buf.append("<a href=\"");
                  buf.append(chars, index, j - index);
                  buf.append('"');
                      buf.append(" target=\"_blank\"");
                  buf.append('>');
                  buf.append(chars, index, j - index);
                  buf.append("</a>");
              } else
              {
                  buf.append(chars, oldend, j - oldend);
              }
              oldend = index = j;
          } else
          if(cur == '[' && index < len - 6 && chars[i = index + 1] == 'u' && chars[++i] == 'r' && chars[++i] == 'l' && (chars[++i] == '=' || chars[i] == ' '))
          {
              j = ++i;
              int u2;
              int u1 = u2 = input.indexOf("]", j);
              if(u1 > 0)
                  u2 = input.indexOf("[/url]", u1 + 1);
              if(u2 < 0)
              {
                  buf.append(chars, oldend, j - oldend);
                  oldend = j;
              } else
              {
                  buf.append(chars, oldend, index - oldend);
                  buf.append("<a href =\"");
                  String href = input.substring(j, u1).trim();
                  if(href.indexOf("javascript:") == -1 && href.indexOf("file:") == -1)
                      buf.append(href);
                  buf.append("\" target=\"_blank");
                  buf.append("\">");
                  buf.append(input.substring(u1 + 1, u2).trim());
                  buf.append("</a>");
                  oldend = u2 + 6;
              }
              index = oldend;
          }
      }
      if(oldend < len)
          buf.append(chars, oldend, len - oldend);
      return buf.toString();
    }
   /**
    * Display a string in html page, call methods: escapeHTMLTags, convertURL,
    *  convertNewlines.
    * @param input string to display
    * @return string
  */
  public static String dspHtml(String input){
    String str=input;
    str= createBreaks(str,80);
    str=escapeHTMLTags(str);
    str=convertURL(str);
    str=convertNewlines(str);
    return str;
  }
}