sqlite Java实现DAO
我正在努力实现这个DOA类。我已经添加了getConnection
和closeConnection
方法,但是,当添加ArrayList<Employees>
时,我总是会得到一个错误。我在下面添加了我的代码。我已经得到了一个UML图来使用
我做错了什么?有人能给我指出正确的方向吗
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
public class EmployeeDAO {
public static void main(String[] args) throws ClassNotFoundException {
Connection con = null;
Statement st = null;
ResultSet rs = null;
Class.forName("org.sqlite.JDBC");
try {
String dbURL = "jdbc:sqlite:employeeDatabase.sqlite";
con = DriverManager.getConnection(dbURL);
st = con.createStatement();
rs = st.executeQuery("SELECT * FROM employees;");
while (rs.next()) {
System.out.println(rs.getString("ID"));
System.out.println(rs.getString("Name"));
System.out.println(rs.getString("Gender"));
System.out.println(rs.getString("DOB"));
System.out.println(rs.getString("Address"));
System.out.println(rs.getString("Postcode"));
System.out.println(rs.getString("NIN"));
System.out.println(rs.getString("JobTitle"));
System.out.println(rs.getString("StartDate"));
System.out.println(rs.getString("Salary"));
System.out.println(rs.getString("Email"));
}
} catch (SQLException ex) {
ex.printStackTrace();
} finally {
try {
if (rs != null) {
rs.close();
}
if (st != null) {
st.close();
}
if (con != null) {
con.close();
}
} catch (SQLException ex) {
ex.printStackTrace();
}
}
}
}
Exception in thread "main" java.lang.Error: Unresolved compilation problems:
Employees cannot be resolved to a type
Illegal modifier for parameter selectallEmployees; only final is permitted
Employees cannot be resolved to a type at EmployeeDAO.main(EmployeeDAO.java:61)
# 1 楼答案
我认为三角形是受保护的或公共的领域。红色框是私有字段。绿色圈都是公共方法。顶部圆上的C是一个构造函数
你的问题代码不符合这些
根据您的图表,您的类需要这样开始编写
你的主要方法根本不应该在那个类中