java - 如何在java中编写set方法将数据库中的值作为用户界面平台

Question

我已经编写了代码，但是我无法编写完整的 set 方法的代码。请告诉我如果我正在制作用户界面，那么我应该如何编写 set 方法。我的代码是 package com.glomindz.mercuri.dao;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

import com.glomindz.mercuri.pojo.Package;
import com.glomindz.mercuri.util.MySingleTon;

  public class PackageServicesDAO {

private Connection connection;

public PackageServicesDAO() {
    // connection = new MySingleTon().getConnection();
    connection = MySingleTon.getInstance().getConnection();

}

public List<Package> get_all_data() {
    List<Package> packageList = new ArrayList<Package>();
     String query = "SELECT * FROM spl_package_master";
    try {
         PreparedStatement stmt = connection.prepareStatement(query);
         boolean execute = stmt.execute();
        System.out.println(execute);
        ResultSet resultSet = stmt.getResultSet();
        System.out.println(resultSet.getMetaData());
        while (resultSet.next()) {
            Package pack = new Package();
            pack.setId(resultSet.getInt("id"));
            pack.setVolume(resultSet.getString("volume"));
            pack.setUnit_type(resultSet.getString("unit_type"));
            pack.setQuantity_in_box(resultSet.getInt("quantity_in_box"));
            pack.setType(resultSet.getString("type"));
            packageList.add(pack);
        }
    } catch (SQLException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
       return packageList;
    } 

    public boolean set_all_data() {
        Package packages = new Package();
        boolean result = false;
            try {
             PreparedStatement stmt = connection.prepareStatement("INSERT INTO spl_package_master(volume,unit_type,quantity_in_box,type)VALUES(?,?,?,?)");
             stmt.setString(1, packages.getVolume());
             stmt.setString(2, packages.getUnit_type());
             stmt.setInt(3, packages.getQuantity_in_box());
             stmt.setString(4, packages.getType());


             result = stmt.execute();


        } 

        catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        return result;
        }


public static void main(String[] args) {
    PackageServicesDAO pacdao = new PackageServicesDAO();
    List<Package> data = pacdao.get_all_data();
    boolean data1 = pacdao.set_all_data();
    System.out.println(data);
    System.out.println(data1);
    System.exit(0);
}

}