JavaFX - TableView not displaying ObservableList correctly.
I originally had this application working, but after refactoring, it's got a bug. There are 2 classes involved, fairly simple. Controller and DBController. Controller is responsible for handling the User Interface. DBController is responsible for accessing the database supplied, and returning the necessary objects back to Controller for processing.
Expected Results
https://user-images.githubuserconten...1b694a6353.PNG
Actual Results
https://user-images.githubuserconten...f867dc7c7f.PNG
Previously, Controller.connect() handled both the database access, ResultSet processing and the UI updating. Here was it's code. (this code produces the desired results)
Controller.connect()
PHP Code:
private void connect() {
StringBuilder dbUrl = new StringBuilder("jdbc:sqlite:");
if (dbUrlTxt.getText().isEmpty()) {
new Alert(Alert.AlertType.ERROR, "Database url must be specified.").showAndWait();
} else {
try {
connection = getConnection(dbUrl.append(dbUrlTxt.getText()).toString());
} catch (SQLException e) {
e.printStackTrace();
}
String tableQuery = "SELECT * FROM sqlite_master WHERE type='table' ORDER BY name";
try (PreparedStatement tableQueryPS = connection.prepareStatement(tableQuery)) {
ResultSet tableNames = tableQueryPS.executeQuery();
while (tableNames.next()) {
Tab tab = new Tab(tableNames.getString("name"));
tabPane.getTabs().add(tab);
TableView<ObservableList> tableView = new TableView<>();
tab.setContent(tableView);
String dataQuery = "SELECT * from " + tableNames.getString("name");
ResultSet tableValues = connection.createStatement().executeQuery(dataQuery);
for (int i = 0; i < tableValues.getMetaData().getColumnCount(); i++) {
final int j = i;
int dataValue = tableValues.getMetaData().getColumnType(i + 1);
// I need to use some generics here on the TableColumn to get rid of the Unchecked call to setCellValueFactory()
TableColumn tableColumn = new TableColumn(tableValues.getMetaData().getColumnName(i + 1));
if (dataValue == 4) {
tableColumn.setCellValueFactory((Callback<TableColumn.CellDataFeatures<ObservableList, Integer>, ObservableValue<String>>) param ->
new SimpleStringProperty(param.getValue().get(j).toString()));
} else if (dataValue == 7) {
tableColumn.setCellValueFactory((Callback<TableColumn.CellDataFeatures<ObservableList, Double>, ObservableValue<String>>) param ->
new SimpleStringProperty(param.getValue().get(j).toString()));
} else if (dataValue == 12) {
tableColumn.setCellValueFactory((Callback<TableColumn.CellDataFeatures<ObservableList, String>, ObservableValue<String>>) param ->
new SimpleStringProperty(param.getValue().get(j).toString()));
}
tableView.getColumns().addAll(tableColumn);
}
ObservableList<ObservableList> data = FXCollections.observableArrayList();
while (tableValues.next()) {
ObservableList<String> row = FXCollections.observableArrayList();
for (int i = 1; i <= tableValues.getMetaData().getColumnCount(); i++) {
row.add(tableValues.getString(i));
}
data.add(row);
}
tableValues.close();
tableView.getItems().addAll(data);
}
tableNames.close();
} catch (SQLException tableQueryException) {
System.err.println(tableQueryException.toString());
}
connectBtn.setDisable(true);
disconnectBtn.setDisable(false);
addBtn.setDisable(false);
updateBtn.setDisable(false);
deleteBtn.setDisable(false);
saveBtn.setDisable(false);
}
}
Now Controller.handleConnect() is in charge, along with an instance of DBController
Controller.handleConnect()
PHP Code:
private void handleConnect() {
if (dbUrlTxt.getText().isEmpty() && !Main.debug) {
new Alert(Alert.AlertType.ERROR, "Database url must be specified.").showAndWait();
} else {
dbController = new DBController();
dbController.connect(dbUrlTxt.getText());
toggleButtons();
//process table
List<String> tableNames = dbController.queryTables();
tableNames.forEach(tableName -> {
if (Main.debug) {
System.out.println(tableName + " table");
System.out.println("-------------------------");
}
Tab tab = new Tab(tableName);
tabPane.getTabs().add(tab);
TableView<ObservableList> tableView = new TableView<>();
tab.setContent(tableView);
//process columns
Map<String, String> columns = dbController.queryColumns(tableName);
if (Main.debug) {
System.out.println("Column Name, Column Type");
System.out.println("-------------------------");
}
columns.forEach((columnName, columnType) -> {
if (Main.debug) { System.out.println(columnName + ", " + columnType); }
TableColumn tableColumn = new TableColumn(columnName);
switch (columnType) {
case "INTEGER":
tableColumn.setCellValueFactory((Callback<TableColumn.CellDataFeatures<ObservableList, Integer>, ObservableValue<String>>) param ->
new SimpleStringProperty(param.getValue().toString()));
case "REAL":
tableColumn.setCellValueFactory((Callback<TableColumn.CellDataFeatures<ObservableList, Double>, ObservableValue<String>>) param ->
new SimpleStringProperty(param.getValue().toString()));
case "TEXT":
case "NONE":
default:
tableColumn.setCellValueFactory((Callback<TableColumn.CellDataFeatures<ObservableList, String>, ObservableValue<String>>) param ->
new SimpleStringProperty(param.getValue().toString()));
}
tableView.getColumns().addAll(tableColumn);
});
if (Main.debug) { System.out.println(); }
// process rows
ObservableList<ObservableList> rows = dbController.queryRows(tableName);
if (Main.debug) {
rows.forEach(row -> System.out.println(row));
System.out.println();
}
tableView.getItems().addAll(rows);
});
}
}
DBController
PHP Code:
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.scene.control.Alert;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.ResultSet;
import java.sql.PreparedStatement;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
class DBController {
private Connection connection;
Connection getConnection() {
return connection;
}
void connect(String databaseURL) {
Connection connection = null;
StringBuilder dbUrl = new StringBuilder("jdbc:sqlite:");
dbUrl.append(databaseURL);
try {
if (Main.debug) {
connection = DriverManager.getConnection("jdbc:sqlite:C:/products.sqlite");
System.out.println("Connection to C:/products.sqlite established\n");
} else {
connection = DriverManager.getConnection(dbUrl.toString());
}
} catch (SQLException connectionException) {
System.err.println(connectionException.toString());
new Alert(Alert.AlertType.ERROR, "There was a problem connecting to the database. Please check that the url is correct.").showAndWait();
}
this.connection = connection;
}
List<String> queryTables() {
String statement = "SELECT * FROM sqlite_master WHERE type='table' ORDER BY name";
List<String> tableNames = new ArrayList<>();
try (PreparedStatement preparedStatement = connection.prepareStatement(statement)) {
ResultSet resultSet = preparedStatement.executeQuery();
while (resultSet.next()) {
tableNames.add(resultSet.getString("name"));
}
resultSet.close();
} catch (SQLException tableQueryException) {
System.err.println(tableQueryException.toString());
}
return tableNames;
}
Map<String, String> queryColumns(String tableName) {
String statement = "PRAGMA table_info(" + tableName + ")";
Map<String, String> columns = new HashMap<>();
try (PreparedStatement preparedStatement = connection.prepareStatement(statement)) {
ResultSet resultSet = preparedStatement.executeQuery();
while (resultSet.next()) {
columns.put(resultSet.getString("name"), resultSet.getString("type"));
}
resultSet.close();
} catch (SQLException columnQueryException) {
System.err.println(columnQueryException.toString());
}
return columns;
}
ObservableList<ObservableList> queryRows(String tableName) {
String statement = "SELECT * from " + tableName;
ObservableList<ObservableList> rows = FXCollections.observableArrayList();
try (PreparedStatement preparedStatement = connection.prepareStatement(statement)) {
ResultSet resultSet = preparedStatement.executeQuery();
while (resultSet.next()) {
ObservableList<String> row = FXCollections.observableArrayList();
for (int i = 1; i <= resultSet.getMetaData().getColumnCount(); i++) {
row.add(resultSet.getString(i));
}
rows.add(row);
}
resultSet.close();
} catch (SQLException rowQueryException) {
System.err.println(rowQueryException.toString());
}
return rows;
}
void disconnect() {
this.connection = null;
if (Main.debug) { System.out.println("Connection Closed"); }
}
}
I know this is fairly complicated but please, any help would be greatly appreciated. I've been trying to fix this bug for over 2 weeks now, no one seems to be able to help. Full source code can be found here. https://github.com/elsheepo/SQLite-Database-Manager
Re: JavaFX - TableView not displaying ObservableList correctly.
The contents of the cells in the table look like the String returned by a List's toString method. The list has three elements.
The same String is added to each of the cells on a row.
Can the code get at the items in the list and add the first item in the list to the first column, the second item to the second column, etc?
Re: JavaFX - TableView not displaying ObservableList correctly.
Quote:
but after refactoring, it's got a bug
I can't advise on specifics as I don't use Java. However in general when a program in any language doesn't do what it is expected then the first port of call is the debugger to trace through the program to find where it deviates from that expected. When this happens then you know where is the problem. Just looking at the code isn't going to tell you what's actually happening whereas tracing through the code will.:)
