public static byte[] stringArray2byteArray(String[] strs) {

public static byte[] stringArray2byteArray(String[] strs) {
  if (strs == null) {
   return null;
  }

  ByteArrayOutputStream byteOutput = new ByteArrayOutputStream();
  DataOutputStream out = new DataOutputStream(byteOutput);
  try {
   for (int i = 0; i < strs.length; i++) {
    byte[] data;
    try {
     data = strs[i].getBytes("utf-8");
    } catch (java.io.UnsupportedEncodingException e) {
     data = strs[i].getBytes();
    }
    out.writeInt(data.length);
    out.write(data);
   }
   out.flush();
   byte[] ret = byteOutput.toByteArray();
   out.close();
   byteOutput.close();
   return ret;
  } catch (IOException e) {
   return null;
  }
 }