屏蔽HTML代码，gbk转iso,iso转gbk----转载自cnjsp

package chimae.util;

/*
 * @author 独孤求胜(chimae)
 * Description:  用于对字符串做一般性的处理
 * Copyright:    Copyright (c) 2003
 * Company:      cnjsp.org
*/

public class stringUtil {
    
    public static String  iso2gbk(String isostr){
      try{
         byte [] byteStr=isostr.getBytes("ISO8859-1");
         String gbkStr=new String(byteStr,"GBK");
         return gbkStr;
        }catch(Exception e){
           return null;
           }
       }
      
   public static String  gbk2iso(String gbkstr){
       try{
           byte [] byteStr=gbkstr.getBytes("GB2312");
           String isoStr=new String(byteStr,"ISO8859-1");
           return isoStr;
               }catch(Exception e){
           return null;
           }
       }
       
          
     //html代码屏蔽
     public  static String filterStr(String str){
               if(str==null)return null;
            StringBuffer sb = new StringBuffer();            
           int n = str.length();
           for (int i = 0; i < n; i++) {
                  char c = str.charAt(i);
                  switch (c) {                  
                          case ' ': sb.append("&nbsp;");break;
                    case '':sb.append("<br/>");break;
                    case '\'':sb.append("'");break;
                    
                    case '<': sb.append("<"); break;
                    case '>': sb.append(">"); break;
                    case '&': sb.append("&"); break;
                    case '"': sb.append("""); break;                        
                    default:  sb.append(c);
              }
        }
        return sb.toString();
    }