Question

我是JavaDb / Derby的新手。我正在将项目从MySQL迁移到Derby（使用JavaFX制作的项目）。我在NetBeans下创建了一个Embedded Db。 GUI具有序列号字段（文本字段），名称字段（文本字段），ImageView和TableView（具有相应数据的列）。以下是与Derby连接的java代码。

    public static Connection ConnectionDb() {
    try{
    String url = "jdbc:derby:Test_JavaDb/webdb;create=true";   

    String user = "root";
    String password = "root";
    String driver = "org.apache.derby.jdbc.EmbeddedDriver";

    Class.forName(driver).newInstance();
    Connection conn = DriverManager.getConnection(url, user, password);
    if (conn != null) {
    System.out.println("Connected to database #1");
    }
    return  conn;

    }catch(Exception e){
    JOptionPane.showMessageDialog(null,e);
    }
    return null;
   }

//BELOW METHOD IS LINKED TO A BUTTON FOR LOADING TABLE   
  @FXML public void LoadTable(){
  data.clear();
  try{
  conn = lrconn.ConnectionDb();
  String sql = "select * from TEST";
  pst = conn.prepareStatement(sql);
  rs = pst.executeQuery();
  while(rs.next()){
  data.add(new TestPOJO(
  rs.getString(1),
  rs.getString(2),
  rs.getString(3)));               
  Table.setItems(data);                    
  }
  pst.close();
  rs.close();   
  }catch(Exception e1){
  }

  Table.setOnMouseClicked((MouseEvent me) -> {  
  try {            
  conn = lrconn.ConnectionDb();
  TestPOJO user = (TestPOJO) Table.getSelectionModel().getSelectedItem();
  String sql = "select * from TEST where SLNO =?";  
  pst = conn.prepareStatement(sql);
  pst.setString(1, user.getSLNO());
  rs = pst.executeQuery();

  while (rs.next()) {
  slnoField.setText(rs.getString(1));
  nameField.setText(rs.getString(2));

  try (InputStream is = rs.getBinaryStream(3)) {
  OutputStream os = new FileOutputStream(new File("photo1.jpg"));
  byte[] content = new byte[1024];
  int size = 0;
  while((size= is.read(content))!=-1){
  os.write(content,0,size);
  }
  os.close();
  } catch (IOException ex) {
  Logger.getLogger(FXMLDocumentController.class.getName()).log(Level.SEVERE, null, ex);
  }
  image1 = new Image("file:photo1.jpg");
  imgvw.setImage(image1);

  rs.close();
  pst.close();
  }catch (SQLException ex) {
  Logger.getLogger(FXMLDocumentController.class.getName()).log(Level.SEVERE, null, ex);
  }  
  });

  Table.setOnKeyReleased((KeyEvent e) -> {
  if(e.getCode()== KeyCode.UP || e.getCode() == KeyCode.DOWN){
  try {
  TestPOJO user = (TestPOJO) Table.getSelectionModel().getSelectedItem();
  String sql = "select * from TEST where SLNO =?";
  pst = conn.prepareStatement(sql);
  pst.setString(1, user.getSLNO());
  rs = pst.executeQuery();
  while (rs.next()) {
  slnoField.setText(rs.getString(1));
  nameField.setText(rs.getString(2));

  try (InputStream is = rs.getBinaryStream(3)) {
  OutputStream os = new FileOutputStream(new File("photo1.jpg"));
  byte[] content = new byte[1024];
  int size = 0;
  while((size= is.read(content))!=-1){
  os.write(content,0,size);
  }os.close();
  }

  image1 = new Image("file:photo1.jpg");
  imgvw.setImage(image1);
  }}catch (FileNotFoundException ex) {
  Logger.getLogger(FXMLDocumentController.class.getName()).log(Level.SEVERE, null, ex);
  } catch (IOException | SQLException ex) {
  Logger.getLogger(FXMLDocumentController.class.getName()).log(Level.SEVERE, null, ex);
  }
  }
  });
  }

连接正常，因为我在执行代码时输出“连接到数据库＃1”（单击LOAD TABLE BUTTON）。但GUI表不会使用嵌入式数据库中的数据进行更新。请帮忙。

将数据从Derby写入JavaFX TableView

0 个答案: