我需要使用java中的下一个按钮逐个显示mySQL数据库的行。但是我很难做到这一点。
以下是我目前的代码。我知道Arraylist和ListIterator应该分开,但我不知道在哪里放它,因为我在结果集中也需要它们。
JButton btnSubmit = new JButton("Next");
btnSubmit.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
try{
Connection connect = DriverManager.getConnection("jdbc:mysql://localhost:3306/anonymization", "root", "password");
Statement statement = connect.createStatement();
String examNames = textExamName.getText();
int examNumber = Integer.parseInt(textNumber.getText());
String selectTable = "Select number, content, choiceA, choiceB, choiceC, choiceD, correctans, * FROM " +examNames+"";
ResultSet examresults = statement.executeQuery("Select * FROM " +examNames+"");
while(examresults.next()){
ArrayList numbers = new ArrayList();
ArrayList contents = new ArrayList();
ArrayList A = new ArrayList();
ArrayList B = new ArrayList();
ArrayList C = new ArrayList();
ArrayList D = new ArrayList();
ArrayList ans = new ArrayList();
ListIterator numberIterator = numbers.listIterator();
ListIterator contentIterator = contents.listIterator();
ListIterator AIterator = A.listIterator();
ListIterator BIterator = B.listIterator();
ListIterator CIterator = C.listIterator();
ListIterator DIterator = D.listIterator();
numbers.add(examresults.getInt("number"));
contents.add(examresults.getString("content"));
A.add(examresults.getString("choiceA"));
B.add(examresults.getString("choiceB"));
C.add(examresults.getString("choiceC"));
D.add(examresults.getString("choiceD"));
ans.add(examresults.getString("correctans"));
if (numberIterator.hasNext() && contentIterator.hasNext() && AIterator.hasNext() && BIterator.hasNext()
&& CIterator.hasNext() && DIterator.hasNext()) {
textAreaQuestion.setText(contentIterator.next().toString());
}
}