Question

我创建了JTable，其中填充了来自MySQL数据库的数据...如果数据库中没有所需的数据，那么JTable应该为空（除了一列，但这并不重要）。

问题是，我的程序只是跳过了JTable Class方法所在的部分...... 这是我的整个代码，我只是不知道为什么这些行被跳过... 我希望它不会太长..我希望你们都能看到我在课堂上所做的事情，并且我会在哪里标明问题所在... 我很抱歉Java命名约定，我不得不使用我的语言中的一些词......

提前谢谢你......

public static void popuniTerminiTable() {

    terminDatum = Listener.yearChoose.getSelectedItem() + "-" + (Listener.monthChoose.getSelectedIndex() + 1) + "-" +  TerminiPanel.izabraniDan;
    //System.out.println("terminDatum = " + terminDatum);
    try {
        String driver = "com.mysql.jdbc.Driver";
        String url = "jdbc:mysql://localhost:3306/ordinacijaDB";
        String name = "root";
        String password = "admin";

        Class.forName(driver);
        Connection connection = DriverManager.getConnection( url, name, password );


        String checkQuery = ("SELECT COUNT(*) FROM ordinacijadb.zakazivanje WHERE termin = '" + terminDatum + " 7:00:00'");
        Statement checkStmt = connection.createStatement();
        ResultSet rsCheck = checkStmt.executeQuery(checkQuery);

        int number = 0;

        while(rsCheck.next()) {
            number = rsCheck.getInt("COUNT(*)");
        }

        System.out.println("number = " + number);

        if (number == 0) {
            String queryTimeStamp = ("SELECT TIMESTAMP '" + terminDatum + " 7:00:00'");
            Statement stmtTimeStamp = connection.createStatement();
            ResultSet rsTimeStamp = stmtTimeStamp.executeQuery(queryTimeStamp);


            while (rsTimeStamp.next()) {
                Timestamp ts = rsTimeStamp.getTimestamp(1);  

                for (int i = 0; i <= 26; i++) {

                    long vreme = ts.getTime(); 

                    vreme1 = new Time(vreme); 
                    SimpleDateFormat sdf = new SimpleDateFormat("HH:mm");
                    String termin = sdf.format(vreme1); 
                    TerminiPanel.zakazivanjeTableModel.setValueAt(termin, i, 0);

                    String queryPolaSata = ("SELECT DATE_ADD('" + terminDatum + " " + vreme1 +"', INTERVAL 30 MINUTE)");
                    Statement stmtPolaSata = connection.createStatement();
                    ResultSet rsPolaSata = stmtPolaSata.executeQuery(queryPolaSata);

                    while(rsPolaSata.next()){
                        ts = rsPolaSata.getTimestamp(1);

                    }
                }
            }
            rsTimeStamp.close();

        } else if(broj == 1)  try {

        Date convertedDate = Date.valueOf(terminDatum);
        String queryUcitajZakazane = ("SELECT * FROM ordinacijaDB.zakazivanje WHERE termin >= '" + convertedDate + " 7:00:00' AND termin <= '" + convertedDate + " 20:00:00'");

        Statement stmtUcitajZakazane = connection.createStatement();
        ResultSet rsUcitajZakazane = stmtUcitajZakazane.executeQuery(queryUcitajZakazane);
        ResultSetMetaData rsmd = rsUcitajZakazane.getMetaData();

        int columns = rsmd.getColumnCount();
        data1.removeAllElements();


        while (rsUcitajZakazane.next()) {

            Vector podatak = new Vector(columns);

            podatak.removeAllElements();
            for (int i = 1; i <= columns; i++) {
                    podatak.add( rsUcitajZakazane.getObject(i) );                   
            }
            data1.addElement(podatak);
        }

        connection.close();
        stmtUcitajZakazane.close();
        rsUcitajZakazane.close();


    } catch (Exception e) {
        e.printStackTrace();
    }

    Vector<String> columnNames1 = new Vector<String>();
    columnNames1.addElement("Termin");
    columnNames1.addElement("Ime i prezime");
    columnNames1.addElement("Napomena");

    DefaultTableModel dtm = new DefaultTableModel(data1, columnNames1); /// LINE ADDED
    JTable zakazivanjeTable1 = new JTable(dtm);   /// LINE ADDED

    zakazivanjeTable1.setRowHeight(27);


    DefaultTableCellRenderer renderer = new DefaultTableCellRenderer(); 
    renderer.setHorizontalAlignment(JTextField.CENTER);

    zakazivanjeTable1.getColumn("Termin").setCellRenderer(renderer);
    zakazivanjeTable1.getColumn("Ime i prezime").setCellRenderer(renderer);
    zakazivanjeTable1.getColumn("Napomena").setCellRenderer(renderer);

    TableColumn column;
    for (int i = 0; i < 3; i++) {
        column = zakazivanjeTable1.getColumnModel().getColumn(i);
        if (i == 0) {
            column.setPreferredWidth(5);
        } else {
            column.setPreferredWidth(170);
       }
    }
    System.out.println("pred dodavanje");
    JScrollPane terminiScrollPane = new JScrollPane(zakazivanjeTable1);
    TerminiPanel.terminPanel.removeAll();
    TerminiPanel.terminPanel.add(TerminiPanel.buttonPanel, BorderLayout.SOUTH);
    TerminiPanel.terminPanel.add(terminiScrollPane, BorderLayout.CENTER);
    TerminiPanel.terminPanel.revalidate();

    } catch (Exception e) {
        e.printStackTrace();
    }

}

Answer 1

不要在JComponents块内创建try - catch - finally，第一个例外是跳过并执行的所有内容都是catch块（然后是finally块），空GUI可以原因很简单，
将所有JComponents创建为局部变量，然后从当前JVM的所有角落访问此Object
不要重新创建JComponents，所有Swing JComponents都有自己的模型，重用此模型，对所有Swing JComponents都有效，并指定为可重复使用（例如TerminiPanel.terminPanel.removeAll(); ---> TerminiPanel.terminPanel.revalidate();）
将所有Statements放在一起，因为看起来像是从JCalendar value(???)链接起来的，thera是一堆MySQL教程，
close() JDBC Object块中的所有finally，其他保留并增加JVM使用的内存
为ResultSetTableModel，TableFromDatabase搜索（在此论坛上，数字时间为数千），方便，清晰，安全JDBC _ to _ JTable
为了更好的帮助，SSCCE发布更短的，可运行的，可编译的问题导致了JTable的局部变量中的硬编码值而不是任何（隐藏任何可以存储的内容）JDBC代码
在阅读Oracles tutorials关于try-catch-finally和JTable的任何内容之前，特别是部分creating table model

程序跳过我创建JTable的行

1 个答案: