Mysql鸡础(从数据库中导入学生数据用list集合存储emp成员)

在此使用statement类后面文章讲述为什么不用statement而用preparestatement

主函数
package cs.itcast.jdbc;

import jdk.nashorn.internal.ir.JumpToInlinedFinally;

import java.sql.*;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;

/
将emp封为对象，然后打印，然后装在集合返回 /
public class jdbcptc {
public List findall() {
//注册驱动
Statement stmt = null;
ResultSet rs = null;
Connection conn = null;
List list = new ArrayList();
try {
Class.forName("com.mysql.cj.jdbc.Driver");
conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/zzt?serverTimezone=GMT&useSSL=false", "root", "root");
String sql = "select *from emp";
stmt = conn.createStatement();
rs = stmt.executeQuery(sql);
emp e= new emp();

        while (rs.next()) {
            int id = rs.getInt("id");
            String ename = rs.getString("name");
            String gender = rs.getString("gender");
            double salary = rs.getDouble("salary"); 
            int dept_id = rs.getInt("dept_id");
            e = new emp();
            e.setDept_id(dept_id);
            e.setEname(ename);
            e.setGender(gender);
            e.setId(id);
            e.setSalary(salary);
            list.add(e);

        }
    } catch (ClassNotFoundException e) {
        e.printStackTrace();
    } catch (SQLException throwables) {
        throwables.printStackTrace();
    } finally {
        if (rs != null) {
            try {
                rs.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
            if (stmt != null) {
                try {
                    rs.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
                if (conn != null) {
                    try {
                        rs.close();
                    } catch (SQLException e) {
                        e.printStackTrace();
                    }
                }

            }
        }
    }
return list;
}

public static void main(String[] args) {
    List<emp> list = new jdbcptc().findall();
    System.out.println(list);
}

}
emp类
package cs.itcast.jdbc;

import java.util.Date;

/、
封装emp表的数据 /
public class emp {
private int id;
private String ename;
private String gender;
private double salary;
private int dept_id;

public int getId() {
    return id;
}

public void setId(int id) {
    this.id = id;
}

public String getEname() {
    return ename;
}

public void setEname(String ename) {
    this.ename = ename;
}

public String getGender() {
    return gender;
}

public void setGender(String gender) {
    this.gender = gender;
}

public double getSalary() {
    return salary;
}

public void setSalary(double salary) {
    this.salary = salary;
}

public int getDept_id() {
    return dept_id;
}

public void setDept_id(int dept_id) {
    this.dept_id = dept_id;
}

@Override
public String toString() {
    return "emp{" +
            "id=" + id +
            ", ename='" + ename + '\'' +
            ", gender='" + gender + '\'' +
            ", salary=" + salary +
            ", dept_id=" + dept_id +
            '}'+'\n';
}

}