插入数据库之前将特殊字符转义

public class CodeFilter {
	/**
	 * to db
	 * @param s
	 * @return
	 */
	public static String toHtml(String s)
    {
    	
        s = Replace(s, "&", "&");
        s = Replace(s, "<", "&lt;");
        s = Replace(s, ">", "&gt;");
        s = Replace(s, "\t", "&nbsp;&nbsp;&nbsp;&nbsp;");
        s = Replace(s, "\r\n", "\n");
        s = Replace(s, "\n", "<br>");
        s = Replace(s, "  ", "&nbsp;&nbsp;");
        s = Replace(s, "'", "&#39;");
        s = Replace(s, "\\", "&#92;");

        
        if (s == null) s = "";
        if (s != null && !s.equals("")) s = s.trim();
        try
		{
          //if (s != null && !s.equals("")) s = new String(s.getBytes("iso-8859-1"));
        }
        catch(Exception e)
        {
          e.printStackTrace();
        }
        return s;
    }
	  /**
	   * to front
	   * @param s
	   * @return
	   */
	  public static String unHtml(String s)
	    {        
	        s = Replace(s, "&amp;", "&");
	        s = Replace(s, "&nbsp;", " ");
	        s = Replace(s, "&#39;", "'");        
	        s = Replace(s, "&lt;", "<");
	        s = Replace(s, "&gt;", ">");
	        s = Replace(s, "<br>", "\n");
	        s = Replace(s, "?D", "—");
	        return s;
	    }
	
	
	
	
	
	
	
	
	
	
	private static String Replace(String s, String s1, String s2)
	    {
	        if(s == null)
	        {
	            return null;
	        }
	        StringBuffer stringbuffer = new StringBuffer();
	        int i = s.length();
	        int j = s1.length();
	        int k;
	        int l;
	        for(k = 0; (l = s.indexOf(s1, k)) >= 0; k = l + j)
	        {
	            stringbuffer.append(s.substring(k, l));
	            stringbuffer.append(s2);
	        }

	        if(k < i)
	        {
	            stringbuffer.append(s.substring(k));
	        }
	        return stringbuffer.toString();
	    }
	 
}