read the output from java exec
Use getErrorStream().
BufferedReader in = new BufferedReader(new InputStreamReader(pr.getErrorStream()));
EDIT:
You can use ProcessBuilder (and also read the documentation)
ProcessBuilder ps=new ProcessBuilder("java.exe","-version");
//From the DOC: Initially, this property is false, meaning that the
//standard output and error output of a subprocess are sent to two
//separate streams
ps.redirectErrorStream(true);
Process pr = ps.start();
BufferedReader in = new BufferedReader(new InputStreamReader(pr.getInputStream()));
String line;
while ((line = in.readLine()) != null) {
System.out.println(line);
}
pr.waitFor();
System.out.println("ok!");
in.close();
System.exit(0);
Java Runtime.getRuntime(): getting output from executing a command line program
Here is the way to go:
Runtime rt = Runtime.getRuntime();
String[] commands = {"system.exe", "-get t"};
Process proc = rt.exec(commands);
BufferedReader stdInput = new BufferedReader(new
InputStreamReader(proc.getInputStream()));
BufferedReader stdError = new BufferedReader(new
InputStreamReader(proc.getErrorStream()));
// Read the output from the command
System.out.println("Here is the standard output of the command:\n");
String s = null;
while ((s = stdInput.readLine()) != null) {
System.out.println(s);
}
// Read any errors from the attempted command
System.out.println("Here is the standard error of the command (if any):\n");
while ((s = stdError.readLine()) != null) {
System.out.println(s);
}
Read the Javadoc for more details here. ProcessBuilder
would be a good choice to use.
How to get an live output from runtime execution in java?
Your process.waitFor()
call is a blocking call, and only unblocks when the process ends, preventing your streams from working, since the streams will be closed when the process has ended.
Read from the stream in a separate thread that you call the .waitFor()
in, or read from the stream before calling .waitFor()
Runtime runtime = Runtime.getRuntime();
Process process = runtime.exec("cmd.exe /c kotlinc -script " + script.getAbsolutePath());
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(process.getInputStream()));
String line = "";
while ((line = bufferedReader.readLine()) != null){
System.out.println(line);
}
int exitValue = process.waitFor();
Incidentally, I would use a ProcessBuilder to get the Process, and not Runtime.getRuntime()
Read live output of process in java
Using https://github.com/zeroturnaround/zt-exec
new ProcessExecutor().command("python", "script.py")
.redirectOutput(new LogOutputStream() {
@Override
protected void processLine(String line) {
...
}
})
.execute();
Read Outputinformation of ffmpeg-process runned from java Runtime.exec(...)
I got the solution: Use ProcesssBuilder and StringBuilder!
Process processDuration = new ProcessBuilder("ffmpeg", "-i", absolutePath).redirectErrorStream(true).start();
StringBuilder strBuild = new StringBuilder();
try (BufferedReader processOutputReader = new BufferedReader(new InputStreamReader(processDuration.getInputStream(), Charset.defaultCharset()));) {
String line;
while ((line = processOutputReader.readLine()) != null) {
strBuild.append(line + System.lineSeparator());
}
processDuration.waitFor();
}
String outputJson = strBuild.toString().trim();
it works fine for me and I'm glad to share this with everyone in the Internet :)
I got the solution from here.
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