maven:一個連接JDBC數據庫的案例

Items類

package mysql.code;
public class Items {
    private Integer id;
    private String name;
    public Integer getId() {
        return id;
    }
    public void setId(Integer id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
}

接口ItemsDao

package mysql.dao;
import mysql.code.Items;
import java.util.List;
public interface ItemsDao {
    public List<Items> findAll()throws Exception;
}

接口實現類ItemsDaoImpl

package mysql.dao.impl;
import mysql.code.Items;
import mysql.dao.ItemsDao;
import java.sql.*;
import java.util.ArrayList;
import java.util.List;
/**
 * 錯誤：?serverTimezone=GMT%2B8 連接jdbc加時間
 * */
public class ItemsDaoImpl implements ItemsDao {
    public List<Items> findAll() throws Exception{
        List<Items> list=new ArrayList<Items>();
        Connection connection=null;
        PreparedStatement pst=null;
        ResultSet rs=null;
        try {
            //加載驅動類
            Class.forName("com.mysql.cj.jdbc.Driver");
            //先獲取connection對象
            connection = DriverManager.getConnection("jdbc:mysql:///maven?serverTimezone=GMT%2B8","root","jh7851192");
            //獲取真正操作數據的對象
            pst = connection.prepareCall("select * from items");
            //執行數據庫查詢操作
            rs = pst.executeQuery();
            //把數據庫結果集轉成java的List集合
            while (rs.next()){
                Items items = new Items();
                items.setId(rs.getInt("id"));
                items.setName(rs.getString("name"));
                list.add(items);
            }
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        }finally {
            connection.close();
            pst.close();
            rs.close();
        }
        return list;
    }
}

測試類ItemsTest

package mysql.test;
import mysql.code.Items;
import mysql.dao.impl.ItemsDaoImpl;
import org.junit.Test;
import java.util.List;
public class ItemsTest {
    @Test
    public void findAll() throws Exception {
        ItemsDaoImpl itemsDao = new ItemsDaoImpl();
        List<Items> list = itemsDao.findAll();
        for (Items items:list){
            System.out.println(items.getName());
        }
    }
}