实验六Java期中考试

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1、期中考试：二、package Exextra_2;import java.util.*;public class Test public static void main(String args) int a=new int10;Scanner scan=new Scanner(System.in);for(int i=0;i10;i+)ai=scan.nextInt();int max=a0;int min=a0;for(int i=0;imax)max=ai;for(int i=0;i10;i+)if(aimin)min=ai;System.out.println(max=+max+ mi

2、n=+min);三、package Exextra_3;public class Point private int x,y;private double s;public Point()public Point(int x,int y)this.x=x;this.y=y;public int getX()return x;public void setX(int x)this.x=x;public int getY()return y;public void setY(int y)this.y=y;public String toString()return (+x+,+y+);public

3、 double distance(Point p1,Point p2)int x1=p1.getX();int y1=p1.getY();int x2=p2.getX();int y2=p2.getY();s=Math.sqrt(x1-x2)*(x1-x2)+(y1-y2)*(y1-y2);return s;package Exextra_3;public class Test public static void main(String args) Point p1=new Point(4,5);Point p2=new Point(2,1);double s=p2.distance(p1,

4、p2);System.out.println(p1.toString();System.out.println(p2.toString();System.out.println(s);四、package Exextra_4;public interface Shapepublic abstract double area();package Exextra_4;public class MyCircle implements Shapeprivate double r;public MyCircle(double r)this.r=r;public double area()return Ma

5、th.PI*r*r;public String toString()return circle: r=+r+ area=+this.area();package Exextra_4;public class MyRectangle implements Shape private double w,h;public MyRectangle(double w,double h)this.w=w;this.h=h;public double area()return w*h;public String toString()return Rectangle: width=+w+ +height=+h

6、+ area=+this.area();package Exextra_4;public class Test public static void main(String args) Shape t1=new MyRectangle(10,5);System.out.println(t1.toString();Shape t2=new MyCircle(3);System.out.println(t2.toString();五、package Exextra_5;import javax.swing.*;import java.awt.*;import java.awt.event.*;pu

7、blic class MyFrm extends JFrame implements ActionListenerint m=0;JButton btn1=new JButton(点我);JButton btn2=new JButton(清零);JLabel lb=new JLabel(共点击了0次);public MyFrm()JPanel jp=(JPanel)this.getContentPane();jp.setLayout(new FlowLayout();jp.add(btn1);jp.add(btn2);jp.add(lb);btn1.addActionListener(this

8、);btn2.addActionListener(this);this.setTitle(ButtonDemol);public void actionPerformed(ActionEvent e)if(e.getSource()=btn1)m=m+1;lb.setText(共点击了+m+次);if(e.getSource()=btn2)m=0;lb.setText(共点击了+m+次);public static void main(String args)MyFrm frm=new MyFrm();frm.setSize(400,100);frm.setVisible(true);数据库调

9、试：package mydb;import java.sql.*;public class StudentDao private String driver = sun.jdbc.odbc.JdbcOdbcDriver;private String url = jdbc:odbc:mydb;private void executeUpdate(String sql) try Class.forName(driver);Connection con = DriverManager.getConnection(url);Statement cmd = con.createStatement();c

10、md.executeUpdate(sql);con.close(); catch (Exception ex) ex.printStackTrace();public void addStudent(String sno, String sname, String major, int zg) String sql = insert into student values( + sno + , + sname+ , + major + , + zg + );executeUpdate(sql);public void deleteStudentBySno(String sno) String

11、sql = delete from student where sno= + sno + ;executeUpdate(sql);public String queryStudents() String rows = null;try Class.forName(driver);Connection con = DriverManager.getConnection(url);Statement cmd = con.createStatement();String sql = select count(*) from student;ResultSet rs = cmd.executeQuer

12、y(sql);rs.next();int rowcount = rs.getInt(1);rows = new Stringrowcount4;sql = select * from student;rs = cmd.executeQuery(sql);rowcount = 0;while (rs.next() for (int i = 1; i = 4; i+)rowsrowcounti - 1 = rs.getString(i);rowcount+;con.close(); catch (Exception ex) ex.printStackTrace();return rows;pack

13、age mydb;import javax.swing.*;import java.awt.*;import java.awt.event.*;public class MainFrm extends JFrame private void initMenu() JMenuBar bar = new JMenuBar();JMenu m1 = new JMenu(学生管理);JMenu m2 = new JMenu(课程管理);JMenuItem m11 = new JMenuItem(学生信息管理);JMenuItem m12 = new JMenuItem(增加学生);JMenuItem

14、m13 = new JMenuItem(退出);m13.addActionListener(new ActionListener()public void actionPerformed(ActionEvent e) exit_Clicked(););m11.addActionListener(new ActionListener() public void actionPerformed(ActionEvent e) newSubFrm_Clicked(););m12.addActionListener(new ActionListener() public void actionPerfo

15、rmed(ActionEvent e) newAddFrm_Clicked(););m1.add(m11);m1.add(m12);m1.addSeparator();m1.add(m13);bar.add(m1);bar.add(m2);this.setJMenuBar(bar);private void newSubFrm_Clicked() new StudentFrm();private void newAddFrm_Clicked() new AddStudent();private void exit_Clicked() if (JOptionPane.showConfirmDia

16、log(this, 确认退出？, 退出系统,JOptionPane.YES_NO_OPTION, JOptionPane.QUESTION_MESSAGE) = JOptionPane.YES_OPTION)System.exit(0);public MainFrm() JPanel jp = (JPanel) this.getContentPane();initMenu();this.setSize(1000, 600);this.setVisible(true);this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);public stati

17、c void main(String args) new MainFrm();package mydb;import javax.swing.*;import javax.swing.table.DefaultTableModel;import java.awt.*;import java.awt.event.*;public class StudentFrm extends JFrame private JTable table = null;private String cols = 学号, 姓名, 专业, 是否有资格 ;private JButton deleteBtn = new JB

18、utton(删除);private StudentDao studentDao = new StudentDao();private void initTable() String rows = studentDao.queryStudents();for (int i = 0; i rows.length; i+)if (0.equals(rowsi3)rowsi3 = 有资格;elserowsi3 = 无资格;table = new JTable(rows, cols);private void updateTable() String rows = studentDao.queryStu

19、dents();for (int i = 0; i -1) String sno = (String) table.getValueAt(row, 0);studentDao.deleteStudentBySno(sno);JOptionPane.showMessageDialog(this, 学号为 + sno + 记录删除成功!);updateTable();public StudentFrm() JPanel jp = (JPanel) this.getContentPane();initTable();JScrollPane jsp_table = new JScrollPane(ta

20、ble);jp.add(jsp_table);JPanel jp_top = new JPanel();jp_top.add(deleteBtn);jp.add(jp_top, BorderLayout.NORTH);deleteBtn.addActionListener(new ActionListener() public void actionPerformed(ActionEvent e) deleteBtn_Clicked(););this.setSize(600, 400);this.setVisible(true);public static void main(String a

21、rgs) new StudentFrm();package mydb;import javax.swing.*;import java.awt.*;import java.awt.event.*;public class AddStudent extends JFrame implements ActionListener StudentDao studentDao = new StudentDao();JButton btn_add=new JButton(确定);JButton btn_del=new JButton(取消);JLabel lb_name=new JLabel(姓名);JL

22、abel lb_snum=new JLabel(学号);JLabel lb_enabled=new JLabel(是否有资格选课);JLabel lb_major=new JLabel(专业);JTextField txt_name=new JTextField();JTextField txt_snum=new JTextField();JTextField txt_enabled=new JTextField();JTextField txt_major=new JTextField();public AddStudent()JPanel jp=(JPanel)this.getConten

23、tPane();JPanel jp1=new JPanel();jp1.setLayout(new GridLayout(5,2,5,10);jp1.add(lb_snum);jp1.add(txt_snum);jp1.add(lb_name);jp1.add(txt_name);jp1.add(lb_major);jp1.add(txt_major);jp1.add(lb_enabled);jp1.add(txt_enabled);jp1.add(btn_add);jp1.add(btn_del);jp.add(jp1,BorderLayout.NORTH);btn_add.addActio

24、nListener(this);btn_del.addActionListener(this);this.setSize(400, 220);this.setVisible(true);public void actionPerformed(ActionEvent e)int zg=0;if(e.getSource()=btn_add)if(txt_snum.getText().equals(是)zg=1;studentDao.addStudent(txt_snum.getText(),txt_name.getText(),txt_major.getText(),zg);dispose();if(e.getSource()=btn_del)dispose();public static void main(String args)new AddStudent();