I need to (compile and) run another class with main method in Java and read its output and later write into its input, but focus on reading first. Let's say i need to test wether the application writes "123" on standart output, here's how i magine it:
public class TestMe {
public static void main(String[] args) {
System.out.println("123");
}
}
...
public class Tester {
public static void main(String[] args) {
Runtime runtime = Runtime.getRuntime();
try {
Process exec = runtime.exec("java works.TestMe");
BufferedReader br = new BufferedReader(new InputStreamReader(exec.getInputStream()));
if (br.readLine().equals("123")) {
System.out.println("Your program is working fine");
} else {
System.out.println("Yout program is bad and you should feel bad");
}
} catch (IOException ex) {
}
}
}
I loaded the Runtime class created process ith exec() method but the reader doesn't read any data and throws null pointer exception (on method readLine()) instead. I have both classes in different package and i am using netbeans, if it anyhow matters. Any help apriciated.
