3データベース内のテーブル内のデータを集合オブジェクトにカプセル化する

1.まずヘッダのクラスを作成する

public class stu {
    private int id;
    private String name;

    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;
    }

    @Override
    public String toString() {
        return "  :   "+id+"     :   "+name;
    }
}

2.変換方法

 public List<stu> FindAll(){
      Connection connection=null;
      Statement statement=null;
      ResultSet resultSet=null;
      ArrayList<stu> stus=null;

      try {
          //    
          Class.forName("com.mysql.jdbc.Driver");
          //  con  
          connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/db3", "root", "fjtgyxa828998");
          // sql  
          String sql="select * from stu";
          //  SQL  
          statement = connection.createStatement();
          //  SQL  
          resultSet = statement.executeQuery(sql);
          stus = new ArrayList<>();
          while(resultSet.next()){
              int id = resultSet.getInt("id");
              String name = resultSet.getString("name");
              stu stu = new stu();
              stu.setId(id);
              stu.setName(name);
              stus.add(stu);


          }


      } catch (ClassNotFoundException e) {
          e.printStackTrace();
      }
      catch (SQLException e) {
          e.printStackTrace();
      }
      finally {
          if (resultSet!=null){
              try {
                  resultSet.close();
              } catch (SQLException e) {
                  e.printStackTrace();
              }

          }
          if (statement!=null){
              try {
                  statement.close();
              } catch (SQLException e) {
                  e.printStackTrace();
              }

          }
          if (connection!=null){
              try {
                  connection.close();
              } catch (SQLException e) {
                  e.printStackTrace();
              }

          }
      }
            return stus;

  }

2.展示方法

public static void main(String[] args) {
        List<stu> stus = new Damo2().FindAll();
        for(stu stu:stus){
            System.out.println(stu.toString());
        }
    }

3.結果

  :   2     :   jun
  :   3     :   feng
  :   4     :   niu
  :   1     :   jiang
  :   5     :   jiang1
  :   6     :   jiang2
  :   7     :   jiang3
  :   8     :   jiang4
  :   9     :   jiang5
  :   10     :   jiang5

Process finished with exit code 0