java base64 加密 解密

public static String encode(String data){
 
    String encode="";
    BASE64Encoder base=new BASE64Encoder();
    try{
        byte[] bytes=data.getBytes("GBK");
        encode=base.encode(bytes);
       }catch(UnsupportedEncodingException e){
           e.printStackTrace();
       }
    return encode;
}

public static String decoder(String data){
 
    String decoder="";
    BASE64Decoder base=new BASE64Decoder();
    try{
        byte[] buffer= base.decodeBuffer(data);
        decoder=new String(buffer,"GBK");
       }catch(IOException e){
           e.printStackTrace();
       }
    return decoder;
}