Java实现学生成绩管理系统(4)

int rs=stmt.executeUpdate(sqlstr);

if(rs>0) { JOptionPane.showMessageDialog(this,\成绩增加成功\成绩信息管理系统

\TION_MESSAGE);

//System.out.println(\添加成功\

} }

else if(e.getSource()==modifyInfo) { grademodify(); }

else if(e.getSource()==clearInfo)

{

gName.setText(\gNum.setText(\gGrade.setText(\

}

catch(Exception E) { }

}

conn.close(); stmt.close();

gName.setEnabled(true); gNum.setEditable(true);

} }

public void grademodify()

{

String kcm=(String)gCourse.getSelectedItem(); String xh=gNum.getText(); try

{ Class.forName(\

String url= \Access Driver (*.mdb)};DBQ= student.mdb\

Connection con=DriverManager.getConnection(url); Statement stm=con.createStatement();

String sqlstr3=\cj set cj='\where xh='\and kcm='\

int result3=stm.executeUpdate(sqlstr3); if(result3>0)

{ JOptionPane.showMessageDialog(this,\修改成功！\修改信息提示\TION_MESSAGE); }

con.close(); stm.close(); }

catch(Exception w){} }

【成绩查询】部分关键代码及注释： public void actionPerformed(ActionEvent E) {

if(pane2!=null)

this.remove(pane2);

if(E.getSource()==bt)

{

String xh=tf1.getText(); try {

//加载驱动

Class.forName(\ String url= \(*.mdb)};DBQ=student.mdb\

Connection conn=DriverManager.getConnection(url); Statement stmt=conn.createStatement();

String sqlstr=\ ResultSet rs=stmt.executeQuery(sqlstr); list=new ArrayList(); while(rs.next()) {

kc newst=new kc();

newst.xh=rs.getString(\ newst.kcm=rs.getString(\ newst.cj=rs.getString(\

list.add(newst);

}

//初始化数组

results=new Object[list.size()][columnNames.length]; for(int i=0;i

//创建二维数组 kc mycj=(kc)list.get(i);

results[i][0]=mycj.xh;

Access

Driver

results[i][1]=mycj.kcm;

results[i][2]=mycj.cj; }

table=new JTable(results,columnNames); JScrollPane jsp=new JScrollPane(table);

pane2=new JPanel();

pane2.add(jsp); //把jsp添加到pane2面板中 this.add(pane2,BorderLayout.CENTER); //把pane2添加到当前窗体 table.addMouseListener(this);

this.validate(); conn.close(); stmt.close(); }

catch(Exception F) {

}

}

} public cjcx() { pane1.setLayout(new FlowLayout()); pane1.add(label1); pane1.add(tf1); pane1.add(bt);

bt.addActionListener(this);

pane3.setLayout(new FlowLayout()); pane3.add(label2); pane3.add(tf2); pane3.add(label3); pane3.add(tf3); pane3.add(label4); pane3.add(tf4);

this.add(pane1,BorderLayout.NORTH);

this.add(pane3,BorderLayout.SOUTH);

this.setSize(600,400); setTitle(\成绩查询\ setVisible(true); }

public void mouseClicked(MouseEvent e) {

cl();

}

//刷新 //关闭数据库连接 //关闭语句

}

public void mouseEntered(MouseEvent e) {

}

public void mouseExited(MouseEvent e) {

}

public void mousePressed(MouseEvent e) {

}

public void mouseReleased(MouseEvent e) { }

public void cl() {

String xh;

String kcm; String cj;

int n=table.getSelectedRow();

xh=table.getValueAt(n,0).toString(); kcm=table.getValueAt(n,1).toString(); cj=table.getValueAt(n,2).toString(); tf2.setText(xh); tf3.setText(kcm);

tf4.setText(cj); }

public static void main(String arg[]) { }

cjcx hh=new cjcx();

3、运行示例及结果分析

【学生成绩管理系统】主界面：

【退出】菜单项：

单击【退出】菜单项时，退出系统。 【学生管理】菜单：

单击【增加学生】菜单项，弹出【请输入要增加的学号】对话框：

单击【确定】按钮，弹出【增加学生】菜单项界面：