pass string from python server to java client

[Shpongle]

Hi all , basically Im developing my final year project for college that consists of a python server an oracle db backend and an android client.

I have started with the server and coded a small python client to test it and for now it works as expected. Now I have started on the actual client and I want to receive a string upon confirmation on the client that it is connected to the server.

it works fine going python to python , using

conn.send('Connected to server')

where conn refers to the connection .
i.e. conn,addr =s.accept() #establish a connection with the client

on the python test client I receive this message as soon as the connection is accepted by the server using print s.recv(1024). With the java one however I get nothing and the program just waits

snippet of the java code

host = InetAddress.getByName("127.0.0.1");
link = new Socket(host,port);
in = new BufferedReader(new InputStreamReader(link.getInputStream()));

//display connection confirmation

String message = in.readLine();
System.out.println (message);



If I can get it in java it will work in android as they use the same socket primitives.

any ideas ? , thanks

[juancarlospaco]

Use SQLite(?)

Have you tried writing the string into a file?

[Shpongle]

the database will store images so I need the binary large object datatype (blob) that oracle offers and Im more familiar with it for the project. I haven't tried to write a file yet as I don't want to incur unnecessary over head on the client side as it will be a mobile application

[dwhitney67]

any ideas ? , thanks

EDIT: Since you are expecting to receive using readLine(), I assume that the server is sending a newline-terminated string. Can you confirm this?

--------------------------

I only tinker with Java once in a blue moon, however when I attempted to duplicate the issue you described, I did not have any issues.

Here's the Java code I played with:


import java.lang.*;
import java.io.*;
import java.net.*;


public class Client
{
private Socket socket = null;
private BufferedReader reader = null;
private BufferedWriter writer = null;

public Client(InetAddress address, int port) throws IOException
{
socket = new Socket(address, port);
reader = new BufferedReader(new InputStreamReader(socket.getInputStream()));
writer = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));
}

public void send(String msg) throws IOException
{
writer.write(msg, 0, msg.length());
writer.flush();
}

public String recv() throws IOException
{
return reader.readLine();
}

public static void main(String[] args)
{
try {
InetAddress host = InetAddress.getByName("127.0.0.1");
Client client = new Client(host, 9000);

client.send("Hello server.\n");
String response = client.recv();
System.out.println("Client received: " + response);
}
catch (IOException e) {
System.out.println("Caught Exception: " + e.toString());
}
}
}

For my server, I used one written in C++.

P.S. I just tried with a Python server; same result... success.

[Shpongle]

hey dwhitney , thanks for your time ,

this is the line that the server sends upon accepting a client connection

self.conn.send('Connected to server')

the client doesn't send a string , it sends an image but thats after it receives the connected to server message from the server.

[Shpongle]

SUCCESS dwhitney your a hero , thanks you really helped me out , It was the \n I was missing . Thank you so much I really appreciate it.