java中文乱码

 StringBuilder stringBuilder = new StringBuilder();
        Process process = null;
        try {
            process = Runtime.getRuntime().exec(cmdCommand);
            BufferedReader bufferedReader = new BufferedReader(
                    new InputStreamReader(process.getInputStream(), "GBK"));
            String line = null;
            while((line=bufferedReader.readLine()) != null)
            {
                stringBuilder.append(line+"\n");
                c.jDisplayText.append(line+"\n");
            }
            return stringBuilder.toString();
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }