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PORedirect a system call output to a file with Java
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copied!<p>Currently having troubles to redirect the output of a small windows batch console to a log file. My Java application needs to start the Runtime.exec() call without waiting it to finish and still log the output. Here is my logger class : </p> <pre><code>public class BatchThreadLogger extends Thread { private Process process; private String logFilePath; private static final Logger logger = Logger.getLogger(BatchThreadLogger.class); public BatchThreadLogger(Process process, String logFilePath) { this.process = process; this.logFilePath = logFilePath; } public void run() { try { // create logging file File file = new File(logFilePath); file.createNewFile(); // create a writer object OutputStream os = new FileOutputStream(file); PrintWriter pw = new PrintWriter(os); // catch the process output in an InputStream InputStreamReader isr = new InputStreamReader(process.getInputStream()); BufferedReader br = new BufferedReader(isr); // wait for the process to complete int processStatus = process.waitFor(); // redirect the output to the log file String line = null; while ((line = br.readLine()) != null) { pw.println(line); } // add a small message with the return code to the log pw.println("********************************************"); pw.println("********************************************"); pw.println("Batch call completed with return status " + processStatus); pw.flush(); os.close(); } catch (IOException e) { logger.error("IOException raised during batch logging on file " + logFilePath, e); } catch (InterruptedException e) { logger.error("InterruptedException raised during batch process execution", e); } } } </code></pre> <p>My call is quite simple : </p> <pre><code>Process process = Runtime.getRuntime().exec(command); BatchThreadLogger logger = new BatchThreadLogger(process, logFilePath); logger.start(); </code></pre> <p>My command is currently just calling my test.bat with two parameters. My test batch now just do : </p> <pre><code>echo "BATCH CALLED WITH PARAMETER %1 AND %2" exit </code></pre> <p>My log file however does contains only : </p> <pre><code>******************************************** ******************************************** Batch call completed with return status 0 </code></pre> <p>I tried to place the <code>waitFor()</code>call before and after the code redirecting the output to the log file, without success. I always see the black screen of the command being launched, but nothing in logs...</p> <p>Any help would be greatly appreciated, I'm missing something, but cannot understand what...</p>

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