实验六,Java期中考试

　期中考试：

　二、 package Exextra_2; import java.util.*; public class Test {

　public static void main(String[] args) {

　 int[] a=new int[10];

　 Scanner scan=new Scanner(System.in);

　 for(int i=0;i<10;i++){

　a[i]=scan.nextInt();

　 }

　 int max=a[0];

　 int min=a[0];

　 for(int i=0;i<10;i++){

　if(a[i]>max)

　 max=a[i];

　 }

　 for(int i=0;i<10;i++){

　if(a[i]<min)

　 min=a[i];

　 }

　 System.out.println("max="+max+" min="+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 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,p2);

　 System.out.println(p1.toString());

　 System.out.println(p2.toString());

　 System.out.println(s);

　} }

　四、 package Exextra_4;

　public interface Shape{

　 public abstract double area(); } package Exextra_4; public class MyCircle implements Shape{

　private double r;

　public MyCircle(double r){

　 this.r=r;

　}

　public double area(){

　 return Math.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+" 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.*; public class MyFrm extends JFrame implements ActionListener{

　int 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);

　 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();

　cmd.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 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.executeQuery(sql);

　rs.next();

　int rowcount = rs.getInt(1);

　rows = new String[rowcount][4];

　sql = "select * from student";

　rs = cmd.executeQuery(sql);

　rowcount = 0;

　while (rs.next()) {

　 for (int i = 1; i <= 4; i++)

　rows[rowcount][i - 1] = rs.getString(i);

　 rowcount++;

　}

　con.close();

　 } catch (Exception ex) {

　ex.printStackTrace();

　 }

　 return rows;

　} }

　package 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 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 actionPerformed(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.showConfirmDialog(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 static 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 JButton("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(rows[i][3]))

　 rows[i][3] = "有资格";

　else

　 rows[i][3] = "无资格";

　 table = new JTable(rows, cols);

　}

　private void updateTable() {

　 String[][] rows = studentDao.queryStudents();

　 for (int i = 0; i < rows.length; i++)

　if ("0".equals(rows[i][3]))

　 rows[i][3] = "有资格";

　else

　 rows[i][3] = "无资格";

　 table.setModel(new DefaultTableModel(rows, cols));

　}

　private boolean isCellEditable(int row,int col){

　 return true;

　}

　 private void deleteBtn_Clicked() {

　 int row = table.getSelectedRow();

　 if (row > -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(table);

　 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[] args) {

　 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");

　JLabel 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.getContentPane();

　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.addActionListener(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();

　} }

推荐访问:期中考试 实验 java