[大数据]java JDBC insert查询返回List对象

一，封装对象

package JDBC;

public class student {
    private int id;
    private String name;
    private String gender;
    private  int age;
    private String address;
    private String qq;
    private String email;
    private String username;
    private String password;

    public int getId() {
        return id;
    }

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

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getGender() {
        return gender;
    }

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

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    public String getQq() {
        return qq;
    }

    public void setQq(String qq) {
        this.qq = qq;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    @Override
    public String toString() {
        return "student{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", gender='" + gender + '\'' +
                ", age=" + age +
                ", address='" + address + '\'' +
                ", qq='" + qq + '\'' +
                ", email='" + email + '\'' +
                ", username='" + username + '\'' +
                ", password='" + password + '\'' +
                '}';
    }
}

二，链接数据库并且查询返回List对象

package JDBC;

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

public class my2 {
    public List<student> findAll() throws ClassNotFoundException, SQLException {
        List<student> list=null;
        Connection connection=null;
        Statement statement=null;
        ResultSet re=null;

                Class.forName("com.mysql.cj.jdbc.Driver");
//        获取数据库链接对象
        connection= DriverManager.getConnection("jdbc:mysql://localhost:3306/day17","root","18388543714a");
//        定义SQL
        String sql="select * from user";
//获取执行对象
        statement=connection.createStatement();
//        执行SQL
        re=statement.executeQuery(sql);
        student student =null;
        list=new ArrayList<student>();
        while (re.next()){
//            获取数据
            int id=re.getInt("id");
            String name=re.getString("name");
            String gender=re.getString("gender");
            int age=re.getInt("age");
            String address=re.getString("address");
            String qq=re.getString("qq");
            String email=re.getString("email");
            String username=re.getString("username");
            String password=re.getString("password");
//            创建student对象
            student =new student();
            student.setId(id);
            student.setName(name);
            student.setGender(gender);
            student.setAge(age);
            student.setAddress(address);
            student.setQq(qq);
            student.setEmail(email);
            student.setUsername(username);
            student.setPassword(password);
//            装载集合
            list.add(student);

        }
        if (connection!=null){
            connection.close();
        }
        if (statement!=null){
            statement.close();
        }
        if (re!=null){
            re.close();
        }

        return list;
    }
}

三.测试

package JDBC;

import java.sql.SQLException;
import java.util.List;

public class ListTest {
    public static void main(String[] args) throws SQLException, ClassNotFoundException {
        List<student> list=new my2().findAll();
        for (student ss:list){
            System.out.println(ss.getName()+"..."+ss.getAge());
        }
    }
}

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