Question

我有一个有两个字符串列表的类。

public class School {
private List<String> students;
private List<String> teachers;
//getters and setters
}

我的DAO课程中有以下方法，其中学校对象已被填充。

public static School fetchSchoolInfo(String schoolName) throws SQLException
{       
    School school = null;
    Connection connection = null;
    PreparedStatement statement = null;
    ResultSet rs = null;
    List<String> students = new ArrayList<String>();
    List<String> teachers = new ArrayList<String>();        
    try {
        connection = createConnection();
        statement = connection.prepareStatement("SELECT COL_STUDENT,COL_TEACHERS FROM SCHOOL WHERE SCHOOLNAME=?");
        statement.setString(1, schoolName);
        rs = statement.executeQuery();
        while(rs.next())
        {
            school = new School();                              
            students.add(rs.getString(1));
            teachers.add(rs.getString(1));
            school.setStudents(students);
            school.setTeachers(teachers);               
        }                       
    } finally{
        rs.close();
        statement.close();
        connection.close();
    }

    return school;
}

现在，如果我这样做，

School school = MyDAO.fetchPersonDeviceIdInfo("SJSU");
System.out.println(school);

学校对象是否拥有SJSU的所有信息？我知道理想情况下我可以自己尝试并检查，但我的应用程序非常复杂，并且需要一段时间才能将此代码与我的应用程序集成。请建议。另外，我需要一个字符串吗？

非常感谢！

Answer 1

更改以下内容：

while(rs.next())
    {
        school = new School();                              
        students.add(rs.getString(1));
        teachers.add(rs.getString(1));
        school.setStudents(students);
        school.setTeachers(teachers);               
    }

到

school = new School(); 
while(rs.next())
    {

        students.add(rs.getString(1));
        teachers.add(rs.getString(2)); // changed

    }  

school.setStudents(students);
school.setTeachers(teachers);

Answer 2

覆盖您的School.toString()方法

class School {
  private List<String> students;
  private List<String> teachers;
  @Override
  public String toString() {
      return "School [students=" + students + ", teachers=" + teachers + "]";
  } 
}

然后你试试

School school = MyDAO.fetchPersonDeviceIdInfo("SJSU");
System.out.println(school);

包含字符串列表的对象

2 个答案: