本次，制作答题系统，要求能够重置题目，提交题目，显示题目，一个页面至少含有五个题目。
照片展示 1.主界面: 代码部分:数据库操作:
import java.sql.*;
import java.util.Scanner;
public class SQL {
public Connection conn = null; //各个数据库资源初始化
public PreparedStatement psm = null;
public Statement stm = null;
public ResultSet rs = null;
public String user = "root"; //用户和密码
public String password = "123456";
public String url = "jdbc:mysql://localhost:3306/timu?serverTimezone=GMT%2B8&userSSL=false"; //连接数据库的地址
public SQL() {
try {
Class.forName("com.mysql.cj.jdbc.Driver"); //加载驱动
conn = DriverManager.getConnection(url, user, password); //建立连接
} catch (ClassNotFoundException | SQLException ex) {
ex.printStackTrace();
}
}
public ResultSet select(){
try {
String sql = "SELECT * FROM select_data"; //SQL语句
psm = conn.prepareStatement(sql);
rs = psm.executeQuery(); //执行sql语句
return rs;
} catch (SQLException e) {
System.out.println("操作异常");
e.printStackTrace();
return null;
}
}
}
这是连接数据库以及读取出数据库内题目的代码，会返回一个结果集。
主函数:
public class Main {
public static void main(String[] args) {
SQL sql = new SQL(); //创建SQL对象，对数据库进行操作
Menu menu = new Menu(sql.select()); //创建一个界面类对象，生成GUI界面。
}
}
界面设计：
1.定义所需要的变量。
public String label = null; public ResultSet rs = null; public ButtonGroup[] buttonGroups = new ButtonGroup[101]; public JRadioButton[] jRadioButtons = new JRadioButton[401]; public JLabel[] jLabels = new JLabel[101]; public String[] result = new String[101];
2.重写构造函数
public Menu(ResultSet rs) {
this.rs = rs;
createMenu();
}
3.设计界面过程以及显示操作过程。
public void createMenu() { //界面创建
JFrame jf = new JFrame("题目界面"); //创建页面
jf.setSize(1000, 800);
jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);//设置可关闭
jf.setLocationRelativeTo(null);//窗口居中
jf.setLayout(null); //自定义界面
jf.setVisible(true);
jf.setResizable(false);
JLabel demo01 = new JLabel(); //标题
jf.add(demo01);
demo01.setText("答题系统");
demo01.setFont(new Font("微软雅黑", Font.BOLD,50));
demo01.setBounds(400,50,400,80);
JLabel demo02 = new JLabel(); //说明
jf.add(demo02);
demo02.setText("(答题期间不能切换屏幕，否则系统将会给予警告!)");
demo02.setFont(new Font("微软雅黑",Font.BOLD,20));
demo02.setBounds(260,130,600,50);
JScrollPane js = new JScrollPane(); //滚动条
js.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS);
js.setHorizontalScrollBarPolicy(ScrollPaneConstants.HORIZONTAL_SCROLLBAR_AS_NEEDED);
js.setBounds(10,200,980,450);
JPanel jp = new JPanel(); //创建一个子页面，存放题目
js.setViewportView(jp);
jf.add(js);
jp.setLayout(null);
js.setVisible(true);
int i = 0;
int j = 0;
int sum = 0;
try {
while (rs.next()){ //生成题目，并且创建单选选择题
int x = 50;
jLabels[i] = new JLabel(String.valueOf(i + 1) + "、" + rs.getString("tihao")); //题目
jp.add(jLabels[i]);
jLabels[i].setBounds(20,i*90,600,40);
jLabels[i].setFont(new Font("微软雅黑",Font.BOLD,20));
result[i] = rs.getString("result"); //存结果
buttonGroups[i] = new ButtonGroup(); //组
jRadioButtons[j] = new JRadioButton("A." + rs.getString("timuA")); //选项
jp.add(jRadioButtons[j]);
buttonGroups[i].add(jRadioButtons[j]);
jRadioButtons[j].setActionCommand(rs.getString("timuA"));
jRadioButtons[j].setBounds((j % 4)*200 + 20,i*90 + 40,200,30);
jRadioButtons[j++].setFont(new Font("微软雅黑",Font.BOLD,20));
jRadioButtons[j] = new JRadioButton("B." + rs.getString("timuB"));
jp.add(jRadioButtons[j]);
buttonGroups[i].add(jRadioButtons[j]);
jRadioButtons[j].setActionCommand(rs.getString("timuB"));
jRadioButtons[j].setBounds((j % 4)*200 + 20,i*90 + 40,200,30);
jRadioButtons[j++].setFont(new Font("微软雅黑",Font.BOLD,20));
jRadioButtons[j] = new JRadioButton("C." + rs.getString("timuC"));
jp.add(jRadioButtons[j]);
buttonGroups[i].add(jRadioButtons[j]);
jRadioButtons[j].setActionCommand(rs.getString("timuC"));
jRadioButtons[j].setBounds((j % 4)*200 + 20,i*90 + 40,200,30);
jRadioButtons[j++].setFont(new Font("微软雅黑",Font.BOLD,20));
jRadioButtons[j] = new JRadioButton("D." + rs.getString("timuD"));
jp.add(jRadioButtons[j]);
buttonGroups[i].add(jRadioButtons[j]);
jRadioButtons[j].setActionCommand(rs.getString("timuD"));
jRadioButtons[j].setBounds((j % 4)*200 + 20,i*90 + 40,200,30);
jRadioButtons[j++].setFont(new Font("微软雅黑",Font.BOLD,20));
i++;
sum++;
}
} catch (SQLException e) {
e.printStackTrace();
}
jp.setPreferredSize(new Dimension(600,sum*90));
JButton jButton = new JButton("提交"); //提交按钮
jf.add(jButton);
jButton.setFont(new Font("微软雅黑",Font.BOLD,20));
jButton.setBounds(150,670,80,40);
JButton jButton01 = new JButton("重新答题"); //重置按钮
jf.add(jButton01);
jButton01.setFont(new Font("微软雅黑",Font.BOLD,20));
jButton01.setBounds(400,670,120,40);
JLabel jLabel = new JLabel(); //显示答对的题目标签
jf.add(jLabel);
jLabel.setText("答对的问题数: ");
jLabel.setFont(new Font("微软雅黑",Font.BOLD,23));
jLabel.setBounds(650,670,230,40);
int finalSum = sum;
jButton01.addActionListener(new AbstractAction() { //重置事件
@Override
public void actionPerformed(ActionEvent e) {
for (int k = 0; k < finalSum; k++){
buttonGroups[k].clearSelection();
}
jLabel.setText("答对的问题数: ");
jf.setVisible(false);
jf.setVisible(true);
}
});
jButton.addActionListener(new AbstractAction() { //提交事务
@Override
public void actionPerformed(ActionEvent e) {
int score = 0;
int idx = 0;
for (int k = 0;k < finalSum;k++){
if (buttonGroups[k].getSelection() == null){
JOptionPane.showMessageDialog(null,"有部分题目没有选择，请仔细检查后重新提交!");
idx = 1;
break;
}
if (buttonGroups[k].getSelection().getActionCommand().equals(result[k])){
score++;
}
}
System.out.println(score);
if (idx == 0){
int i = JOptionPane.showConfirmDialog(null,"你是否要提交吗，提交后成绩不能修改!",
"请确定",JOptionPane.YES_NO_CANCEL_OPTION, JOptionPane.WARNING_MESSAGE);
if (i == 0){
jLabel.setText("答对的问题数: " + String.valueOf(score));
}
}
}
});
}
