java - 从数据库中读取数据并存储在 Array List 对象中

Question

你好，我想在 html 页面上显示我的数据库表的全部内容。我试图先从数据库中获取记录并存储在 ArrayList 中，但是当我在 html 页面上返回数组列表时，它显示只有最后一条记录重复作为我的数据库表的计数。这是下面的代码:

public ArrayList<CustomerDTO> getAllCustomers() 
{
    ArrayList<CustomerDTO> customers = new ArrayList<CustomerDTO>();
    CustomerDTO customer = null;
    Connection c;
    try {
        c = openConnection();
        Statement statement = c.createStatement();
        String s = "SELECT * FROM customer";

        ResultSet rs = statement.executeQuery(s);
        int g =0;

        while (rs.next()) {

            customer.setId(rs.getInt("id"));
            customer.setName(rs.getString("name"));

            customer.setAddress(rs.getString("address"));
            customer.setPhone(rs.getString("phone"));
            customer.setEmail(rs.getString("email"));
            customer.setBountPoints(rs.getInt("bonuspoint"));
            customer.setTotalsale(rs.getInt("totalsale"));

            customers.add(customer);
        }

        rs.close();
    } catch (Exception e) {
        System.out.println(e);
    }

    return customers;
}

Answer 1

试试下面的代码

public static ArrayList<Customer> getAllCustomer() throws ClassNotFoundException, SQLException {
    Connection conn=DBConnection.getDBConnection().getConnection();
    Statement stm;
    stm = conn.createStatement();
    String sql = "Select * From Customer";
    ResultSet rst;
    rst = stm.executeQuery(sql);
    ArrayList<Customer> customerList = new ArrayList<>();
    while (rst.next()) {
        Customer customer = new Customer(rst.getString("id"), rst.getString("name"), rst.getString("address"), rst.getDouble("salary"));
        customerList.add(customer);
    }
    return customerList;
}

这是我的模型类

public class Customer {
private String id;
private String name;
private String salary;
private String address;
public String getId() {
    return id;
}
public void setId(String id) {
    this.id = id;
}
public String getName() {
    return name;
}
public void setName(String name) {
    this.name = name;
}
public String getSalary() {
    return salary;
}
public void setSalary(String salary) {
    this.salary = salary;
}
public String getAddress() {
    return address;
}
public void setAddress(String address) {
    this.address = address;
}
}

这是我的 View 方法

  private void reloadButtonActionPerformed(java.awt.event.ActionEvent evt) {                                             
    try {
        ArrayList<Customer> customerList = null;
        try {
            try {
                customerList = CustomerController.getAllCustomer();
            } catch (SQLException ex) {
                Logger.getLogger(veiwCustomerFrame.class.getName()).log(Level.SEVERE, null, ex);
            }
        } catch (Exception ex) {
            Logger.getLogger(ViewCustomerForm.class.getName()).log(Level.SEVERE, null, ex);
        }
        DefaultTableModel tableModel = (DefaultTableModel) customerTable.getModel();
        tableModel.setRowCount(0);
        for (Customer customer : customerList) {
            Object rowData[] = {customer.getId(), customer.getName(), customer.getAddress(), customer.getSalary()};
            tableModel.addRow(rowData);
        }


    } catch (Exception ex) {
        Logger.getLogger(ViewCustomerForm.class.getName()).log(Level.SEVERE, null, ex);
    }

}