java - MySQL结果集到java数组

Question

我目前正在尝试做的事情做得不太好。目的是从 MySQL 表中获取所有信息并将其放入数组中。一旦进入数组，我将使用 java 中的优先级队列并尝试让它与该队列一起工作......但这不是我目前遇到的问题。

公共(public)静态无效数组(字符串args []){ //创建优先级队列

   try { 
        String url = "jdbc:mysql://localhost:3306/project"; 
        Connection conn = DriverManager.getConnection(url,"root","nbuser"); 

        PreparedStatement stmt = conn.prepareStatement("SELECT user_id,s_date,e_date,d_date,department,projectname,projectapplication FROM booking");
        ResultSet rs; 
        rs=stmt.executeQuery();

                  List<User> userList = new ArrayList<User>();
        while(rs.next()) {
        User user = new User(); //issue here with non-static variable
        user.userid(rs.getString("user_id"));
        user.s_date(rs.getObject("s_date"));
        user.e_date(rs.getObject("e_date"));
        user.d_date(rs.getObject("d_date"));
        user.department(rs.getObject("department"));
        user.projectname(rs.getObject("projectname"));
        user.projectapplication(rs.getObject("projectapplication"));
        user.priority(rs.getObject("priority"));

        userList.add(user);
     }

        conn.close(); 
    } catch (Exception e) { 
        System.err.println("Got an exception! "); 
        System.err.println(e.getMessage()); 
    } 
} 

目的是让它遍历表中的所有不同部分并将它们填充到一个数组中，但我一直坚持填充数组。

如有任何帮助，我们将不胜感激。

编辑:

public class User {
public String userid;
public String s_date;
public String e_date;
public String d_date;
public String department;
public String projectname;
public String projectapplication;
public int priority;

    private void userid(String string) {
        throw new UnsupportedOperationException("Not yet implemented");
    }

    private void s_date(Object object) {
        throw new UnsupportedOperationException("Not yet implemented");
    }

    private void e_date(Object object) {
        throw new UnsupportedOperationException("Not yet implemented");
    }

    private void d_date(Object object) {
        throw new UnsupportedOperationException("Not yet implemented");
    }

    private void department(Object object) {
        throw new UnsupportedOperationException("Not yet implemented");
    }

    private void projectname(Object object) {
        throw new UnsupportedOperationException("Not yet implemented");
    }

    private void projectapplication(Object object) {
        throw new UnsupportedOperationException("Not yet implemented");
    }

    private void priority(Object object) {
        throw new UnsupportedOperationException("Not yet implemented");
    }
}

与此类似？

Answer 1

使用 SQL 表中的相应字段创建一个 User 类，并将每个用户保存在一个列表中。

  List<User> userList = new ArrayList<User>();
  while(rs.next()) {
     User user = new User();
     user.setId(rs.getString("user_id"));
     user.setStartDate(rs.getTimestamp("s_date");
     ....
     userList.add(user);
  }
  return userList;

编辑:

  class User {
   private String id;
   private Date startDate;
   //other fields need to be declared as well as their setter methods

   public void setStartDate(Date startDate) {
      this.startDate = startDate;
   }

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

我还建议您查看 JPA 和 Hibernate。