JAVAsql。SQLException:mysql中结果集结束后出错

Question

我试图从数据库中读取数据，并将ResultSet存储在ArrayList中。但是，我在打印arraylist时收到错误java.sql.SQLException: After end of result set。根据这个link，我已经检查过没有两次调用我的result.next()。有谁有更好的方法来存储结果集吗？然后我可以在我想要的地方打印出来

Statement stmt=con.createStatement();  
            ResultSet rsVehicle=stmt.executeQuery("select * from vehicle");  
            while(rsVehicle.next()) {  
                vehicleList.add(rsVehicle);
            }
            System.out.println(vehicleList.size());

            for(int i=0;i<vehicleList.size();i++) {
                System.out.println(vehicleList.get(i).getInt(1)+"  "+vehicleList.get(i).getString(2)+"  "+vehicleList.get(i).getString(3)+"  "+
                        vehicleList.get(i).getString(4)+"  "+vehicleList.get(i).getString(5)+"  "+vehicleList.get(i).getString(6)+"  "+
                        vehicleList.get(i).getString(7)+"  "+vehicleList.get(i).getString(8)+"  "+vehicleList.get(i).getString(9)+"  "+
                        vehicleList.get(i).getString(10)+"  "+vehicleList.get(i).getString(11)+"  "+vehicleList.get(i).getString(12)+"  "+
                        vehicleList.get(i).getString(13)+"  "+vehicleList.get(i).getString(14)+"  "+vehicleList.get(i).getString(15));
            }

            PreparedStatement ps;
            ps =con.prepareStatement("SELECT * from job WHERE date = ?");
            ps.setString(1, date);
            ResultSet rsJob=ps.executeQuery();  
            while(rsJob.next()) {  
                jobList.add(rsJob);
            }
            System.out.println(jobList.size());

            for(int i=0;i<jobList.size();i++) {
                System.out.println(jobList.get(i).getInt(1)+"  "+jobList.get(i).getString(2)+"  "+jobList.get(i).getString(3)+"  "+
                        jobList.get(i).getString(4)+"  "+jobList.get(i).getString(5)+"  "+jobList.get(i).getString(6)+"  "+
                        jobList.get(i).getString(7)+"  "+jobList.get(i).getString(8)+"  "+jobList.get(i).getString(9)+"  "+
                        jobList.get(i).getString(10)+"  "+jobList.get(i).getString(11)+"  "+jobList.get(i).getString(12)+"  "+
                        jobList.get(i).getString(13)+"  "+jobList.get(i).getString(14)+"  "+jobList.get(i).getString(15));
            }

Answer 1

在代码中，将结果集添加到列表中，然后迭代该列表以获取数据，但正确的流程是：

• 从结果集中提取数据并将其放入列表中
• 之后，您可以迭代列表以打印结果

代码应类似于：

// Create a new list of vehicles
List<Vehicle> vehicleList = new ArrayList<>();
Statement stmt=con.createStatement();  
ResultSet rsVehicle=stmt.executeQuery("select * from vehicle");  
while(rsVehicle.next()) {  
    // Create a new vehicle for each record returned from the query
    Vehicle vehicle = new Vehicle();

    // Set to the vehicle each property taken from that record
    vehicle.setBrand(rsVehicle.getString(1));
    ...

    // Add that vehicle to the list
    vehicleList.add(vehicle);
}

...

// Iterate the list and print each field you need
for (Vehicle vehicle: vehicleList) {
   // PRint each vehicle
   System.out.println("Vechicle brand: " + vehicle.getBrand());
}

注意：如果重新定义类Vehicle的方法toString，则可以直接调用System.out.println(vehicle);