I want my main thread to wait until the background thread completes. But, this makes my UI freeze. I want to achieve this without freezing my UI. Please help me out. I am new to JavaFX.
My Code is ---
waitNotifyClass wait1 = new waitNotifyClass();
private void download(ActionEvent event) throws SQLException, IOException, InterruptedException {
try (Connection conn = ......getConnection()) {
/// opening filechooser
FileChooser fc = new FileChooser();
FileChooser.ExtensionFilter extFilter = new FileChooser.ExtensionFilter("Compressed(zipped) Folder (*.zip)", "*.zip");//Compressed(zipped) Folder (*.gz)", "*.gz"
fc.getExtensionFilters().add(extFilter);
String downloadsLocation = System.getProperty("user.home") + "/Downloads/";
/// get a File file with name as you save in file chooser
file = fc.showSaveDialog(downloadMultiTraceFileButton.getScene().getWindow());
file.mkdirs();
File sourceFile = file;
String s = file.getAbsolutePath().substring(0, file.getAbsolutePath().length() - 4);
destFile = new File(s);
if (sourceFile.renameTo(destFile)) {
System.out.println("File renamed successfully");
} else {
System.out.println("Failed to rename file");
}
/// object of the folder made after renaming
File theDir = new File(destFile.getAbsolutePath());
/// Iterating through the slected item of trace files one by one for create a file and then fill it
Task task = new Task() {
@Override
protected Void call() throws Exception {
for (String str : traceFileListView.getSelectionModel().getSelectedItems()) {
File myFile = new File(theDir.getAbsolutePath() + "\\" + str);
/// make new file if myFile doesnt exist
if (!myFile.exists()) {
myFile.createNewFile();
}
/// get writer object of FileWriter for writing finally on file from
FileWriter writer = new FileWriter(myFile);
/// query for getting content of trace file
String querySubPart = "select * from table_name='" + str + "'";
PreparedStatement preparedStatement = conn.prepareStatement(querySubPart);
ResultSet resultSet = preparedStatement.executeQuery();
resultSet.setFetchSize(200);
/// writing into file from resultSet
System.out.println("writing before while loop " + Thread.currentThread());
while (resultSet.next()) {
try {
writer.write(resultSet.getString(1));
System.out.println(resultSet.getString(1));
} catch (IOException ex) {
System.out.println("inside try of write");
}
}
writer.close();
}
wait1.notifyFunction();
updateProgress(1, 1);
return null;
}
};
System.err.println("Thread created" + Thread.currentThread());
new Thread(task).start();
wait1.waitFunction();
//// closing the window open where download button was there
((Stage) generateTraceFileButton.getScene().getWindow()).close();
/// getting sourcepath folder which is to be zipped
String sourcePath = theDir.getAbsolutePath();
// name of zip folder
String destinationpath = theDir + ".zip";
System.out.println(destinationpath);
packInZipCode(sourcePath, destinationpath);
} catch (SQLException e) {
System.out.println("Exception caught \n" + e.toString());
if (e.toString().trim().toUpperCase().contains("----")) {
....
}
}
}
I am sure that my UI is freezing because of wait1.waitFunction() because this is making my UI thread wait and freeze the UI. I want to wait for it but without freezing the app.
Edited--
why do I want to achieve this?
because If I will not stop my UI thread, it will go ahead and zip my file. but that same file is being used by the background thread also. So I won't get the desired output. Also, my main task is to do the downloading part(here it is heavy, so take time) in the background thread. At the same time, I don't want my main thread to freeze.
I tried this--->
Implemented task.setOnSucceded just after thread creation so that my JavaFx thread will execute this part only after task is completed.
But in this case , background thread(task is executing here) is losing connection .
Got this error-->
java.sql.SQLException: Connection is closed
at this line-->
preparedStatement = conn.prepareStatement(querySubPart);
My new Code looks like this -->
private void downloadMultiTraceFiles(ActionEvent event) throws SQLException, IOException, InterruptedException {
try (Connection conn = mainApp.getHikariDataSource().getConnection()) {
/// opening filechooser
FileChooser fc = new FileChooser();
FileChooser.ExtensionFilter extFilter = new FileChooser.ExtensionFilter("Compressed(zipped) Folder (*.zip)", "*.zip");//Compressed(zipped) Folder (*.gz)", "*.gz"
fc.getExtensionFilters().add(extFilter);
String downloadsLocation = System.getProperty("user.home") + "/Downloads/";
/// get a File file with name as you save in file chooser
System.out.println("Inside runlator" + Thread.currentThread());
file = fc.showSaveDialog(downloadMultiTraceFileButton.getScene().getWindow());
System.out.println("Path of file->" + file.getAbsolutePath());
file.mkdirs();
File sourceFile = file;
String s = file.getAbsolutePath().substring(0, file.getAbsolutePath().length() - 4);
destFile = new File(s);
if (sourceFile.renameTo(destFile)) {
System.out.println("File renamed successfully" + Thread.currentThread());
} else {
System.out.println("Failed to rename file");
}
/// object of the folder made after renaming
File theDir = new File(destFile.getAbsolutePath());
/// Iterating through the slected item of trace files one by one for create a file and then fill it
Task task = new Task() {
@Override
protected Void call() throws Exception {
for (String str : traceFileListView.getSelectionModel().getSelectedItems()) {
System.out.println("inside of the for loop " + Thread.currentThread());
File myFile = new File(theDir.getAbsolutePath() + "\\" + str);
/// make new file if myFile doesnt exist
if (!myFile.exists()) {
myFile.createNewFile();
}
/// get writer object of FileWriter for writing finally on file from
System.out.println("t1--------- " + Thread.currentThread());
FileWriter writer = new FileWriter(myFile);
System.out.println("t2----------- " + Thread.currentThread());
/// query for getting content of trace file
String querySubPart = "select payload from gv$diag_trace_file_contents where trace_filename='" + str + "'";
System.out.println("t3----------- " + Thread.currentThread());
PreparedStatement preparedStatement = conn.prepareStatement(querySubPart);
System.out.println("t4----------- " + Thread.currentThread());
ResultSet resultSet = preparedStatement.executeQuery();
resultSet.setFetchSize(200);
/// writing into file from resultSet
System.out.println("writing before while loop " + Thread.currentThread());
while (resultSet.next()) {
try {
writer.write(resultSet.getString(1));
System.out.println(resultSet.getString(1));
} catch (IOException ex) {
System.out.println("inside try of write");
}
}
writer.close();
}
wait1.notifyFunction();
updateProgress(1, 1);
return null;
}
};
System.err.println("Thread created" + Thread.currentThread());
new Thread(task).start();
wait1.waitFunction();
task.setOnSucceeded((e) -> {
System.out.println("Inside set on succeeded"+Thread.currentThread());
//// closing the window open where download button was there
((Stage) generateTraceFileButton.getScene().getWindow()).close();
/// getting sourcepath folder which is to be zipped
System.out.println("before zip");
String sourcePath = theDir.getAbsolutePath();
// name of zip folder
String destinationpath = theDir + ".zip";
System.out.println(destinationpath);
try {
packInZipCode(sourcePath, destinationpath);
} catch (IOException ex) {
Logger.getLogger(GenerateTraceFilesController.class.getName()).log(Level.SEVERE, null, ex);
}
});
} catch (SQLException e) {
System.out.println("Exception caught \n" + e.toString());
if (e.toString().trim().toUpperCase().contains("ORA-48127")) {
....
}
}
}
