I am trying to call a simple test.exe program that is as simple as
int main()
{
int a;
cout<<"Welcome\n";
while(cin>>a&&a!=0)
cout<<"you entered "<<a<<endl;
}
I want to run it from a java program as a process and send a message + receive from it. I use a process with two threads as follows:
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
public class Processproblem {
public static void main(String[] args)throws IOException, InterruptedException {
final Process process;
try {
process = Runtime.getRuntime().exec("test.exe");
} catch (IOException e1) {
e1.printStackTrace();
return;
}
new Thread(new Runnable() {
public void run() {
String line;
BufferedReader br = new BufferedReader(new InputStreamReader(process.getInputStream()));
try {
while ((line = br.readLine()) != null) {
System.out.println("[OUT] " + line);
}
} catch (IOException e) {
e.printStackTrace();
}
}
}).start();
new Thread(new Runnable() {
public void run() {
try {
byte[] buffer = new byte[1024];
int reading=0;
System.out.println(reading);
BufferedWriter bw= new BufferedWriter(new OutputStreamWriter(process.getOutputStream()));
while(reading!=-1)
{
reading= System.in.read(buffer);
for(int i = 0; i < buffer.length; i++) {
int intValue = new Byte(buffer[i]).intValue();
if (intValue == 0) {
reading = i;
break;
}
else
{
bw.append((char)intValue);
}
}
bw.newLine();
bw.flush();
}
} catch (Exception e) {
}
}
}
).start();
}
}
But they do not work as expected. When I run the program, it just displays the message "Welcome \ n", and then stops to enter. When I give an integer and hit enter in the java console, it does nothing.
What am I doing wrong? These are two separate threads, so why do they block each other? Are there any problems in my concept?