import java.nio.ByteBuffer;

import java.nio.CharBuffer;

import java.nio.charset.Charset;

import java.nio.charset.CharsetDecoder;  

public class TopNTool

{

    /**

     * String 转换 ByteBuffer

     * @param str

     * @return

     */

    public static ByteBuffer getByteBuffer(String str)

    {

        return ByteBuffer.wrap(str.getBytes());

    }  

    /**

     * ByteBuffer 转换 String

     * @param buffer

     * @return

     */

    public static String getString(ByteBuffer buffer)

    {

        Charset charset = null;

        CharsetDecoder decoder = null;

        CharBuffer charBuffer = null;

        try

        {

            charset = Charset.forName("UTF-8");

            decoder = charset.newDecoder();

            // charBuffer = decoder.decode(buffer);//用这个的话，只能输出来一次结果，第二次显示为空

            charBuffer = decoder.decode(buffer.asReadOnlyBuffer());

            return charBuffer.toString();

        }

        catch (Exception ex)

        {

            ex.printStackTrace();

            return "";

        }

    }

}