I have a Python app and a Java app running simultaneously. I want Java to start the Python process and then communicate using the normal STDIN/STDOUT streams with Python. I have started the process correctly and have two threads to handle the two I/O streams.
OUTPUT THREAD:
class output2 extends Thread {
Process process;
OutputStream stdin;
BufferedWriter writer;
Scanner in = new Scanner(System.in);
output2(Process p) {
try {
process = p;
stdin = process.getOutputStream();
writer = new BufferedWriter(new OutputStreamWriter(stdin));
} catch (Exception e) {
System.out.println("ERROR output2(): " + e);
}
}
@Override
public void run() {
System.out.println("Starting OUTPUT THREAD");
try {
while (true) {
String input = in.nextLine();
writer.write(input);
writer.flush();
}
} catch (Exception e) {
System.out.println("ERROR output2_run(): " + e);
}
System.out.println("Ending OUTPUT THREAD");
}
}
INPUT THREAD :
class input2 extends Thread {
Process process;
InputStream stdout;
BufferedReader reader;
input2(Process p) {
try {
process = p;
stdout = process.getInputStream();
reader = new BufferedReader(new InputStreamReader(stdout));
} catch (Exception e) {
System.out.println("ERROR input2(): " + e);
}
}
@Override
public void run() {
System.out.println("Started INPUT THREAD");
try {
while (true) {
System.out.println(Thread.currentThread().getName() + " is executing");
if (reader.readLine() != null) {
System.out.println("Stdout: " + reader.readLine());
}
Thread.sleep(1000);
System.out.println(Thread.currentThread().getName() + " stopped executing");
}
} catch (Exception e) {
System.out.println("ERROR input2_run(): " + e);
}
System.out.println("Ending INPUT THREAD");
}
}
MAIN :
public class My_Java {
public static void main(String args[]) {
File file = new File("C:\\Location\\");
try {
Process process = Runtime.getRuntime().exec("C:\\Python27\\python.exe chat_from_file.py", null, file);
input2 input = new input2(process);
output2 output = new output2(process);
input.setName("INPUT THREAD");
output.setName("OUTPUT THREAD");
input.start();
output.start();
} catch (Exception e) {
System.out.println("ERROR main(): " + e);
}
}
}
This doesn't seem to give any response at all. It starts both threads, says INPUT THREAD is executing but nothing after that. Where am I going wrong?
