Sending large JSON files via sockets

Question

Well this is embarassing. I am trying to send a large JSON file via sockets, and naturally the string exceeded the limit, so I tried compressing it, but for some strange reason I only get a single byte on the server-side. This is what I have so far:

Server-side:

StringBuilder sb = new StringBuilder();
String str;
while((str = request.getReader().readLine()) != null)
    sb.append(str);
Socket client = new Socket("localhost", 8081);

OutputStream outServer = client.getOutputStream();
DataOutputStream out = new DataOutputStream(new GZIPOutputStream(outServer));
byte[] buff = sb.toString().getBytes("UTF-8");
System.out.println(buff.length);
out.writeInt(buff.length);
out.write(buff);
out.flush(); 
client.close();

The length of buf is 198153 in the particular case that I am trying to make this work.

The client-side:

ServerSocket serverSocket = new ServerSocket(8081);
Socket server = serverSocket.accept();

DataInputStream in = new DataInputStream(new GZIPInputStream(server.getInputStream()));
System.out.println(in.available());
int len = in.readInt();
byte[] buff = new byte[len];
in.readFully(buff);
String response = new String(buff, "UTF-8");
System.out.println(response);

updateMessage(response);
server.close();
serverSocket.close();

the in.available() is just 1 in this case, and the program doesn't execute anymore, it just stops there (it doesn't terminate though) Any ideas? I thought that it might be helpful to get an outside perspective, because it might be something that I am missing out, something obvious. Thanks.

Answer 1

Since you are sending just one message per connection (which would be inefficient for small messages but for larger enough ones it doesn't matter so much) I would just send the entire message as text and read the whole message in one go.

NOTE: your code drops all newlines which I suspect wasn't intended.

For writing one message per connection.

try (Socket client = new Socket("localhost", 8081);
    Writer writer = new OutputStreamWriter(new GZIPOutputStream(client.getOutputStream()), "UTF-8")) {
    char[] chars = new char[8192];
    for (int len; (len = request.read(chars)) > 0;)
         writer.write(chars, 0, len);
}

for reading

try (Socket server = serverSocket.accept();
     Reader reader = new InputStreamReader(new GZIPInputStream(server.getInputStream()), "UTF-8")) {
     // read the text as above.
}

Answer 2

原来，我只需要删除GZIPInputStream和GZIPOutputStream，因此无论何时要发送带有套接字的大字符串，都可以随意使用此技术，我在Internet上也找不到任何其他/更好的方法。