一个成绩管理系统，有问题 ，不知道怎么
程序代码：package 成绩管理系统;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.table.DefaultTableModel;
public class AddScore extends JPanel implements ActionListener {
String[] columnNames = new String[] { "姓名", "学期", "课程ID", "成绩" };
DefaultTableModel dtmScore = new DefaultTableModel(columnNames, 57);
JTable jtAddScore = new JTable(dtmScore);
JScrollPane jspScore = new JScrollPane(jtAddScore);
JComboBox jcbCourse = new JComboBox();
JComboBox jcbClassName = new JComboBox();
JComboBox jcbTerm = new JComboBox();
Connection con = JBCUtil.getConnection();
PreparedStatement ps = null;
ResultSet rs = null;
ResultSetMetaData meta = null;
String sql = null;
int cols = 0;
int rowCount = 0;
public AddScore() {
CreateAddScoreGUI();
}
public void actionPerformed(ActionEvent e) {
String str = e.getActionCommand();
if ("查询".equals(str)) {
// 当点击查询时，用searchScore()方法对其进行处理
searchScore();
} else if ("提交".equals(str)) {
// 当点击提交时，用tryCommit()方法对其进行处理
tryCommit();
} else if ("退出".equals(str)) {
this.setVisible(false);
}
}
public void tryCommit() {
if (cols < 1)
return;
sql = "insert into scorexx values(?,?,?,?)";
try {
ps = con.prepareStatement(sql);
String[] value = new String[4];
for (int k = 0; k < rowCount; k++) {
for (int i = 1; i <= cols + 1; i++) {
// 如果成绩为空，取消提交操作，并给出提示。
if (jtAddScore.getValueAt(k, i - 1) != null) {
value[i - 1] = jtAddScore.getValueAt(k, i - 1).toString();
} else {
if (i == 4)
JOptionPane.showMessageDialog(null, "无效成绩输入！成绩不能为空");
return;
}
// 如果成绩字段里面不是数字，则取消本次操作??
// String str = "^[0-9]{1}[0-9]?[0-9]?$";
// if (i == 4) {
// if(jtAddScore.getValueAt(k, i - 1) instanceof Integer){
// if(
// Integer.parseInt(value[3])<0||Integer.parseInt(value[3])>100)
// {JOptionPane.showMessageDialog(null, "成绩只能大于0且小于100");
// return;}
// }
// }
System.out.print(value[i - 1]);
}
ps.setString(1, value[0]);
ps.setString(2, value[1]);
ps.setString(3, value[2]);
ps.setInt(4, Integer.parseInt(value[3]));
ps.executeUpdate();
();
System.out.println();
}
JOptionPane.showMessageDialog(null, "提交成功：更新 " + rowCount + " 条记录！");
} catch (Exception ew) {
ew.printStackTrace();
}
}
// 自动添加课程下拉列表中的课程
public void addCourseToJCheckBoxCourse() {
String courseName = null;
sql = "select cname from coursexx";
try {
ps = con.prepareStatement(sql);
rs = ps.executeQuery();
ResultSetMetaData meta = rs.getMetaData();
int cols = meta.getColumnCount();
while (rs.next()) {
for (int i = 1; i <= cols; i++) {
courseName = rs.getString(i);
System.out.println(courseName);
jcbCourse.addItem(courseName);
rowCount++;
}
}
();
} catch (Exception ers) {
ers.printStackTrace();
try {
con.rollback();
} catch (Exception er) {
er.printStackTrace();
}
}
}
public void searchScore() {
// 每次查询之前清空之前的结果
for (int k = 0; k < 50; k++) {
for (int i = 0; i < cols; i++) {
jtAddScore.setValueAt(null, k, i);
}
}
// Method1:JDBC Method2:Hibernate
String cName = jcbCourse.getSelectedItem().toString().trim();
sql = "select x.sname,k.term, from " + "choicesxx x join Coursexx k " + "on and try {
ps = con.prepareStatement(sql);
ps.setString(1, cName);
rs = ps.executeQuery();
meta = rs.getMetaData();
cols = meta.getColumnCount();
boolean flag = true;
String result = null;
int k = 1;
while (rs.next()) {
for (int i = 1; i <= cols; i++) {
result = rs.getString(i);
jtAddScore.setValueAt(result, k - 1, i - 1);
}
rowCount = k++;
}
} catch (Exception exx) {
exx.printStackTrace();
}
}
// 产生用户界面
public void CreateAddScoreGUI() {
this.setLayout(new FlowLayout());
JLabel jlCourse = new JLabel("课程：");
jcbCourse.addActionListener(this);
jcbCourse.addItem(new String("请选择课程"));
addCourseToJCheckBoxCourse();
this.add(jlCourse);
this.add(jcbCourse);
// JLabel jlClassName = new JLabel("班级：");
// jcbClassName.addActionListener(this);
// jcbClassName.addItem(new String("请选择班级"));
// addClassNameToJCheckBoxClassName();
// this.add(jlClassName);
// this.add(jcbClassName);
// JLabel jlTerm = new JLabel("学期：");
// jcbTerm.addActionListener(this);
// jcbTerm.addItem(new String("请选择学期"));
// addTermToJCheckBoxTerm();
// this.add(jlTerm);
// this.add(jcbTerm);
JButton jbSearch = new JButton("查询");
jbSearch.addActionListener(this);
JButton jbOK = new JButton("提交");
jbOK.addActionListener(this);
JButton jbExit = new JButton("退出");
jbExit.addActionListener(this);
this.add(jbSearch);
this.add(jbOK);
this.add(jbExit);
this.add(jspScore);
this.setVisible(true);
this.setSize(500, 600);
}
public static void main(String[] args) {
new AddScore();
}
}
在网上找的，用来学习一下，空出来的那一行JBCUtil显示不存在，不知道怎么搞，有大神来帮忙看看吗
[此贴子已经被作者于2017-10-9 15:35编辑过]
解决了，谢谢