j2me socket读取服务器汉语出乱码_J2ME

j2me socket读取服务器中文出乱码
conn = (SocketConnection) Connector.open(addr ,Connector.READ_WRITE);
conn.setSocketOption(SocketConnection.KEEPALIVE, 100);
is = conn.openInputStream();
os = conn.openOutputStream();

int i = is.available();
String str = "";
byte[] bstr = new byte[i];
try{
is.read(bstr);

str=new String(bstr,"UTF-8"); ///////////////问题在这里，我转UTF8的时候报错说转码错误是怎么回事啊？
}catch(Exception e)
{
}

请各位帮忙下，若是我的读取服务器方式错误的话希望大家指点下，若我不转UTF8的话在手机上又是乱码，很急，请各位帮忙谢谢！！！！

------解决方案--------------------------------------------------------

Java code

/**     * 读流生成byte[]，全读取     *      * @param is     * @return     */    public static byte[] readFully(InputStream is) {        byte[] bytes = null;        if (is != null) {            try {                ByteArrayOutputStream baos = new ByteArrayOutputStream();                int l = 0;                byte[] b = new byte[1024];                while ((l = is.read(b)) != -1) {                    baos.write(b, 0, l);                }                bytes = baos.toByteArray();                baos.close();                baos = null;            } catch (IOException e) {                e.printStackTrace();            }        }        return bytes;    }
------解决方案--------------------------------------------------------
ByteArrayOutputStream baos = new ByteArrayOutputStream();  
System.out.println("baos=="+baos); 

这时候还没往里头写数据呢，当然是空的...
你要根据返回的byte[]是不是空来判断有没有数据

------解决方案--------------------------------------------------------
byte[] bstr=readFully(is);
str=new String(bstr,"UTF-8");  
System.out.println("str=="+str);