Java读取不同字符集格式的文本文件

                                           String sql = "";
        BufferedReader reader = null;
        try ...{
            File f = new File(filePath);
            
            reader = new BufferedReader(new InputStreamReader(new FileInputStream(f),encoding));
            StringBuffer strbContent=new StringBuffer();
            while(true)
            ...{
                String line = reader.readLine();
                if(line == null)
                    break;
                                
                strbContent.append(" " + line + " ");
            }
            sql = strbContent.toString();            
        }catch(Exception e)
        ...{
            return null;
        }
        finally
        ...{
            try
            ...{
                if(reader!=null)
                ...{
                    reader.close();
                }
            }
            catch(Exception e)
            ...{
            }
        }