M.v*_*aal 3 database javafx tableview
所以我想要发生的事情是让 tableview 在编辑后更新数据库中的数据。我想在这里使用 SetOnEditCommit 方法。单元格编辑确实有效，但它永远不会更新，也没有错误。首先，如果这种方法实际上有效（可能不是），我有点无能为力，因为很难找到这个特定事物的一些来源。我发现的来源并没有真正的帮助。因此，如果有人知道它为什么不更新，或者在这里提供替代选项，那就太好了。
提到的部分：
columnType.setOnEditCommit(new EventHandler<TableColumn.CellEditEvent<UserDetails, String>>() {
@Override
public void handle(TableColumn.CellEditEvent<UserDetails, String> event) {
updataData();
}
});
tableview.setItems(null);
tableview.setItems(data);
}
public void updataData() {
Connection connection = null;
try {
connection = DriverManager.getConnection("jdbc:mysql://37.128.148.113:3306/FYS", "FYS", "Kcj8g87~");
Statement con = connection.createStatement();
//connection
TablePosition pos = tableview.getSelectionModel().getSelectedCells().get(0);
int row = pos.getRow();
TableColumn col = pos.getTableColumn();
String data1 = (String) col.getCellObservableValue(row).getValue();
//cell
UserDetails row1 = tableview.getSelectionModel().getSelectedItem();
c1 = row1.getId();
//row
//tableview variables
con.execute("UPDATE gevonden_bagage SET type = 'data1' WHERE koffer_id = 'c1' ");
//Query
} catch (SQLException ex) {
System.err.println("Error" + ex);
}
}
//get connection, get celldata, get id data from first row, update cell with selected id
完整的控制器类：
package simple;
import java.net.URL;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ResourceBundle;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.event.EventHandler;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.control.Button;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TablePosition;
import javafx.scene.control.TableView;
import javafx.scene.control.cell.PropertyValueFactory;
import javafx.scene.control.cell.TextFieldTableCell;
/**
*
* @author admin
*/
public class FXMLUserController extends SimpleController implements Initializable {
@FXML
public TableView<UserDetails> tableview;
@FXML
public TableColumn<UserDetails, String> columnId;
@FXML
public TableColumn<UserDetails, String> columnType;
@FXML
public TableColumn<UserDetails, String> columnKleur;
@FXML
public TableColumn<UserDetails, String> columnLuchthaven;
@FXML
public TableColumn<UserDetails, String> columnKenmerken;
@FXML
public TableColumn<UserDetails, String> columnStatus;
@FXML
public TableColumn<UserDetails, String> columnDatum;
@FXML
private Button btnLoad;
//declare observable list for database data
private ObservableList<UserDetails> data;
private DbConnection dc;
String c1;
@FXML
//strings for getRow method
@Override
public void initialize(URL url, ResourceBundle rb) {
dc = new DbConnection();
loadDataFromDatabase();
}
@FXML
public void loadDataFromDatabase() {
try {
Connection conn = dc.Connect();
data = FXCollections.observableArrayList();
// Execute query and store result in a resultset
ResultSet rs = conn.createStatement().executeQuery("SELECT * FROM gevonden_bagage");
while (rs.next()) {
//get strings
data.add(new UserDetails(rs.getString(1), rs.getString(2), rs.getString(3), rs.getString(4), rs.getString(5),
rs.getString(6), rs.getString(7)));
}
} catch (SQLException ex) {
System.err.println("Error" + ex);
}
//Set cell values to tableview.
tableview.setEditable(true);
tableview.getSelectionModel().setCellSelectionEnabled(true);
columnType.setCellFactory(TextFieldTableCell.forTableColumn());
columnKleur.setCellFactory(TextFieldTableCell.forTableColumn());
columnLuchthaven.setCellFactory(TextFieldTableCell.forTableColumn());
columnKenmerken.setCellFactory(TextFieldTableCell.forTableColumn());
columnStatus.setCellFactory(TextFieldTableCell.forTableColumn());
columnDatum.setCellFactory(TextFieldTableCell.forTableColumn());
//makes columns editable
columnId.setCellValueFactory(new PropertyValueFactory<>("id"));
columnType.setCellValueFactory(new PropertyValueFactory<>("type"));
columnKleur.setCellValueFactory(new PropertyValueFactory<>("kleur"));
columnLuchthaven.setCellValueFactory(new PropertyValueFactory<>("luchthaven"));
columnKenmerken.setCellValueFactory(new PropertyValueFactory<>("kenmerken"));
columnStatus.setCellValueFactory(new PropertyValueFactory<>("status"));
columnDatum.setCellValueFactory(new PropertyValueFactory<>("datum"));
columnType.setOnEditCommit(new EventHandler<TableColumn.CellEditEvent<UserDetails, String>>() {
@Override
public void handle(TableColumn.CellEditEvent<UserDetails, String> event) {
updataData();
}
});
tableview.setItems(null);
tableview.setItems(data);
}
public void updataData() {
Connection connection = null;
try {
connection = DriverManager.getConnection("jdbc:mysql://37.128.148.113:3306/FYS", "FYS", "Kcj8g87~");
Statement con = connection.createStatement();
//connection
TablePosition pos = tableview.getSelectionModel().getSelectedCells().get(0);
int row = pos.getRow();
TableColumn col = pos.getTableColumn();
String data1 = (String) col.getCellObservableValue(row).getValue();
//cell
UserDetails row1 = tableview.getSelectionModel().getSelectedItem();
c1 = row1.getId();
//row
//tableview variables
con.execute("UPDATE gevonden_bagage SET type = 'data1' WHERE koffer_id = 'c1' ");
//Query
} catch (SQLException ex) {
System.err.println("Error" + ex);
}
}
//get connection, get celldata, get id data from first row, update cell with selected id
@FXML
public void getRow() {
TablePosition pos = tableview.getSelectionModel().getSelectedCells().get(0);
int row = pos.getRow();
TableColumn col = pos.getTableColumn();
// this gives the value in the selected cell:
String data1 = (String) col.getCellObservableValue(row).getValue();
System.out.println(data1);
//CURRENTLY UNUSED METHOD
}
}
模型类：
import javafx.beans.property.SimpleStringProperty;
import javafx.beans.property.StringProperty;
/**
*
* @author admin
*/
public class UserDetails {
private final StringProperty id;
private final StringProperty type;
private final StringProperty kleur;
private final StringProperty luchthaven;
private final StringProperty kenmerken;
private final StringProperty status;
private final StringProperty datum;
//Default constructor
public UserDetails(String id, String type, String kleur, String luchthaven, String kenmerken, String status, String datum) {
this.id = new SimpleStringProperty(id);
this.type = new SimpleStringProperty(type);
this.kleur = new SimpleStringProperty(kleur);
this.luchthaven = new SimpleStringProperty(luchthaven);
this.kenmerken = new SimpleStringProperty(kenmerken);
this.status = new SimpleStringProperty(status);
this.datum = new SimpleStringProperty(datum);
}
//getters
public String getId() {
return id.get();
}
public String getType() {
return type.get();
}
public String getKleur() {
return kleur.get();
}
public String getLuchthaven() {
return luchthaven.get();
}
public String getKenmerken() {
return kenmerken.get();
}
public String getStatus() {
return status.get();
}
public String getDatum() {
return datum.get();
}
//setters
public void setId(String value) {
id.set(value);
}
public void setType(String value) {
type.set(value);
}
public void setKleur(String value) {
kleur.set(value);
}
public void setLuchthaven(String value) {
luchthaven.set(value);
}
public void setKenmerken(String value) {
kenmerken.set(value);
}
public void setStatus(String value) {
status.set(value);
}
public void setDatum(String value) {
datum.set(value);
}
//property values
public StringProperty idProperty() {
return id;
}
public StringProperty typeProperty() {
return type;
}
public StringProperty kleurProperty() {
return kleur;
}
public StringProperty luchthavenProperty() {
return luchthaven;
}
public StringProperty kenmerkenProperty() {
return kenmerken;
}
public StringProperty statusProperty() {
return status;
}
public StringProperty datumProperty() {
return datum;
}
}
默认情况下，TableColumn 编辑提交处理程序是非空的，默认处理程序会尝试覆盖当前正在编辑的行中项目的属性值。当 Cell.commitEdit(Object) 方法传入新值时，它能够做到这一点，并且通过触发的 CellEditEvent 将其传递给编辑提交处理程序。只需调用 TableColumn.CellEditEvent.getNewValue() 即可检索此值。
请务必注意，如果您使用自己的 EventHandler 调用 TableColumn.setOnEditCommit(javafx.event.EventHandler)，那么您将删除默认处理程序。除非您随后处理对属性（或相关数据源）的写回，否则不会发生任何事情。
所以问题是，通过设置onEditCommiton columnType，您删除了实际typeProperty在UserDetails实例中更新的默认处理程序。最后
String data1 = (String) col.getCellObservableValue(row).getValue();
给出旧值，您对数据库的更新不会改变任何东西。
此外，您在创建 SQL 语句的方式上有错误。您将WHERE子句中的 id设为文字值'c1'（而不是包含在变量中的值c1，类似地将 的值设置type为文字值'data1'，而不是变量中的值data1。
这是一个修复程序，以及一些代码的简化和一些避免SQL 注入攻击的更好做法：
columnType.setOnEditCommit(event -> {
UserDetails user = event.getRowValue();
user.setType(event.getNewValue());
updateData("type", event.getNewValue(), user.getId());
});
进而
private void updateData(String column, String newValue, String id) {
// btw it is way better to keep the connection open while the app is running,
// and just close it when the app shuts down....
// the following "try with resources" at least makes sure things are closed:
try (
Connection connection = DriverManager.getConnection("jdbc:mysql://37.128.148.113:3306/FYS", "FYS", "Kcj8g87~");
PreparedStatement stmt = connection.prepareStatement("UPDATE gevonden_bagage SET "+column+" = ? WHERE koffer_id = ? ");
) {
stmt.setString(1, newValue);
stmt.setString(2, id);
stmt.execute();
} catch (SQLException ex) {
System.err.println("Error");
// if anything goes wrong, you will need the stack trace:
ex.printStackTrace(System.err);
}
}