Run bat file in Java and wait 2
- by Savvas Dalkitsis
This is a followup question to my other question : http://stackoverflow.com/questions/2434125/run-bat-file-in-java-and-wait
The reason i am posting this as a separate question is that the one i already asked was answered correctly. From some research i did my problem is unique to my case so i decided to create a new question. Please go read that question before continuing with this one as they are closely related.
Running the proposed code blocks the program at the waitFor invocation. After some research i found that the waitFor method blocks if your process has output that needs to be proccessed so you should first empty the output stream and the error stream. I did those things but my method still blocks. I then found a suggestion to simply loop while waiting the exitValue method to return the exit value of the process and handle the exception thrown if it is not, pausing for a brief moment as well so as not to consume all the CPU. I did this:
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
public class Test {
public static void main(String[] args) {
try {
Process p = Runtime.getRuntime().exec(
"cmd /k start SQLScriptsToRun.bat" + " -UuserName -Ppassword"
+ " projectName");
final BufferedReader input = new BufferedReader(new InputStreamReader(p.getInputStream()));
final BufferedReader error = new BufferedReader(new InputStreamReader(p.getErrorStream()));
new Thread(new Runnable() {
@Override
public void run() {
try {
while (input.readLine()!=null) {}
} catch (IOException e) {
e.printStackTrace();
}
}
}).start();
new Thread(new Runnable() {
@Override
public void run() {
try {
while (error.readLine()!=null) {}
} catch (IOException e) {
e.printStackTrace();
}
}
}).start();
int i = 0;
boolean finished = false;
while (!finished) {
try {
i = p.exitValue();
finished = true;
} catch (IllegalThreadStateException e) {
e.printStackTrace();
try {
Thread.sleep(500);
} catch (InterruptedException e1) {
e1.printStackTrace();
}
}
}
System.out.println(i);
} catch (IOException e) {
e.printStackTrace();
}
}
}
but my process will not end! I keep getting this error:
java.lang.IllegalThreadStateException: process has not exited
Any ideas as to why my process will not exit? Or do you have any libraries to suggest that handle executing batch files properly and wait until the execution is finished?
