1、实验目的与要求
(1) 掌握Java应用程序的打包操作;
(2) 了解应用程序存储配置信息的两种方法;
(3) 掌握基于JNLP协议的java Web Start应用程序的发布方法;
(5) 掌握Java GUI 编程技术。
一、理论知识
JAR 文件
1、JAR文件是压缩的,它使用 ZIP 压缩格式。
2、Java程序的打包:程序编译完成后,程序员 将.class文件压缩打包为.jar文件后,GUI界面 程序就可以直接双击图标运行。
3、⚫jar命令格式: jar {ctxui} [vfm0Me] [jar-file] [manifest-file] [entry-point] [-C dir] files…
⚫-c 创建一个新的或者空的存档文件并加入文件。
-m 将一个清单文件(manifest)添加到JAR文件中。
-u 更新已存在的JAR文件(c和u不能同时出现)
-x 解压存档中的命名的(或所有的〕文件
⚫(1) 创建JAR文件:jar cf jar-file(文件名) input-file(s)
(2) 查看JAR文件:jar tf jar-file (查看t) t---want to view the Table of contents of the JAR file.
(*代表通配符,任意长度的字符。 ?仅代表一个位置是任意的)
(3) 提取JAR文件:jar xf jar-file [archived-file(s)] x---want to extract files from the JAR archive
(4) 更新JAR文件:jar uf jar-file input-file(s) u---want to update an existing JAR file.
(5) 索引JAR文件:jar i jar-file i---index an existing JAR file.
4、清单文件:每个JAR文件中包含一个用于描述归档特征的清单文 件(manifest)。清单文件被命名为MANIFEST.MF,它位于JAR文件的一个特殊的META-INF子目录中。
(2)清单文件的节与节之间用空行分开,最后一行必须以 换行符结束。否则,清单文件将无法被正确地读取。
例:– 创建一个包含清单的JAR文件,应该运行: jar cfm MyArchive.jar manifest.mf com/*.class
(3)运行JAR文件:用户可以通过下面的命令来启动应用程序: java –jar MyProgram.jar
窗口操作系统,可通过双击JAR文件图标来启动应用程序。
5、资源:Java中,应用程序使用的类通常需要一些相关的数据文件,这些文件称为资源(Resource)。
(–图像和声音文件。 –带有消息字符串和按钮标签的文本文件。 二进制数据文件,如:描述地图布局的文件。)
(1)利用资源机制对于非类文件也可以进行同样操作 ,具体步骤如下:
– 获得资源的Class对象。
– 如果资源是一个图像或声音文件,那么就需要调用 getresource(filename)获得资源的URL位置,然后利 用getImage或getAudioClip方法进行读取。 – 如果资源是文本或二进制文件,那么就可以使用 getResouceAsStream方法读取文件中的数据。
(2)资源文件可以与类文件放在同一个目录中,也可以将资源文件放在其它子目录中。具体有以下两 种方式:
–相对资源名:如data/text/about.txt 它会被解释为相对于加载这个资源的类所在 的包。
–绝对资源名:如/corejava/title.txt
(3)编译、创建JAR文件和执行这个程序的命令如下: – javac ResourceTest.java
– jar cvfm ResourceTest.jar ResourceTest.mf *.class *.gif *.txt
– java –jar ResourceTest.jar
⚫
◼ 应用程序首选项存储
◼ Java Web Start
⚫ Java Web Start是一个用Java编写的应用程序,它是Sun 公司推出的一项在Internet上发布应用程序的技术;
⚫ 通过Java Web Start可以使一个应用程序很容易地通过 web部署在各个平台上,包括Windows,Linux,Solaris等。
⚫ Java Web Start的工作过程是基于Java Network Launch Protocol(JNLP) 协议的 。 一个后缀为 JNLP的文件包含了应用程序的说明以及如何启动 这个应用程序的所有信息,Java Web Start技术 部署应用程序的关键就在于JNLP文件的编写以及 发布。
2、实验内容和步骤
实验1: 导入第13章示例程序,测试程序并进行代码注释。
测试程序1
l 在elipse IDE中调试运行教材585页程序13-1,结合程序运行结果理解程序;
l 将所生成的JAR文件移到另外一个不同的目录中,再运行该归档文件,以便确认程序是从JAR文件中,而不是从当前目录中读取的资源。
l 掌握创建JAR文件的方法;
package resource; import java.awt.*; import java.io.*; import java.net.*; import java.util.*; import javax.swing.*; /** * @version 1.41 2015-06-12 * @author Cay Horstmann */ public class ResourceTest { public static void main(String[] args) { EventQueue.invokeLater(() -> { JFrame frame = new ResourceTestFrame(); frame.setTitle("ResourceTest");//设置标题 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);//关闭界面的操作 frame.setVisible(true);//使结果为可见的 }); } } /** * A frame that loads image and text resources. */ class ResourceTestFrame extends JFrame { //定义像素长和宽 private static final int DEFAULT_WIDTH = 300; private static final int DEFAULT_HEIGHT = 300; public ResourceTestFrame()//定义ResourceTestFrame类 {//利用about.gif图像文件制作图标 setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT); URL aboutURL = getClass().getResource("about.gif"); Image img = new ImageIcon(aboutURL).getImage(); //在找到ResourceTest类的地方查找about.gif图像文件 setIconImage(img); JTextArea textArea = new JTextArea(); //读取about.txt文件 InputStream stream = getClass().getResourceAsStream("about.txt"); try (Scanner in = new Scanner(stream, "UTF-8")) { while (in.hasNext()) textArea.append(in.nextLine() + "\n"); }//捕获异常 add(textArea); } }
测试程序2
l 在elipse IDE中调试运行教材588页-589程序13-2,结合程序运行结果理解程序;
l 了解Properties类中常用的方法;
package properties; import java.awt.EventQueue; import java.awt.event.*; import java.io.*; import java.util.Properties; import javax.swing.*; /** * A program to test properties. The program remembers the frame position, size, * and title. * @version 1.01 2015-06-16 * @author Cay Horstmann */ public class PropertiesTest { public static void main(String[] args) { EventQueue.invokeLater(() -> {//lamda表达式 PropertiesFrame frame = new PropertiesFrame(); frame.setVisible(true); }); } } /** * A frame that restores position and size from a properties file and updates * the properties upon exit. */ class PropertiesFrame extends JFrame { private static final int DEFAULT_WIDTH = 300; private static final int DEFAULT_HEIGHT = 200; private File propertiesFile;//属性映射文件 private Properties settings; public PropertiesFrame() { // get position, size, title from properties //获得位置、大小、标题 String userDir = System.getProperty("user.home"); //找到用户的主目录,调用System.getProperty方法 File propertiesDir = new File(userDir,".corejava"); if (!propertiesDir.exists()) propertiesDir.mkdir(); propertiesFile = new File(propertiesDir, "program.properties"); Properties defaultSettings = new Properties(); //defaultSettings构造器提供属性映射参数 defaultSettings.setProperty("left", "0"); defaultSettings.setProperty("top", "0"); defaultSettings.setProperty("width", "" + DEFAULT_WIDTH); defaultSettings.setProperty("height", "" + DEFAULT_HEIGHT); defaultSettings.setProperty("title", ""); settings = new Properties(defaultSettings); if (propertiesFile.exists()) try (InputStream in = new FileInputStream(propertiesFile)) { settings.load(in);//使文件加载属性 } catch (IOException ex)//抛出异常 { ex.printStackTrace(); } int left = Integer.parseInt(settings.getProperty("left")); int top = Integer.parseInt(settings.getProperty("top")); int width = Integer.parseInt(settings.getProperty("width")); int height = Integer.parseInt(settings.getProperty("height")); setBounds(left, top, width, height); // if no title given, ask user String title = settings.getProperty("title"); if (title.equals("")) title = JOptionPane.showInputDialog("Please supply a frame title:"); if (title == null) title = ""; setTitle(title); addWindowListener(new WindowAdapter()//添加窗口指定监听器 { public void windowClosing(WindowEvent event) { settings.setProperty("left", "" + getX()); settings.setProperty("top", "" + getY()); settings.setProperty("width", "" + getWidth()); settings.setProperty("height", "" + getHeight()); settings.setProperty("title", getTitle());// try (OutputStream out = new FileOutputStream(propertiesFile)) { settings.store(out, "Program Properties"); } catch (IOException ex) { ex.printStackTrace(); } System.exit(0); } }); } }
测试程序3
l 在elipse IDE中调试运行教材593页-594程序13-3,结合程序运行结果理解程序;
l 了解Preferences类中常用的方法;
package preferences; import java.awt.*; import java.io.*; import java.util.prefs.*; import javax.swing.*; import javax.swing.filechooser.*; /** * A program to test preference settings. The program remembers the frame * position, size, and title. * @version 1.03 2015-06-12 * @author Cay Horstmann */ public class PreferencesTest { public static void main(String[] args) { EventQueue.invokeLater(() -> { PreferencesFrame frame = new PreferencesFrame(); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setVisible(true); }); } } /** * A frame that restores position and size from user preferences and updates the * preferences upon exit. */ class PreferencesFrame extends JFrame { private static final int DEFAULT_WIDTH = 300; private static final int DEFAULT_HEIGHT = 200; private Preferences root = Preferences.userRoot();//访问树中的一个结点 private Preferences node = root.node("/com/horstmann/corejava");//提供一个节点路径名 public PreferencesFrame() { // get position, size, title from preferences int left = node.getInt("left", 0); int top = node.getInt("top", 0); int width = node.getInt("width", DEFAULT_WIDTH); int height = node.getInt("height", DEFAULT_HEIGHT); setBounds(left, top, width, height);//设置节点信息 // if no title given, ask user String title = node.get("title", ""); if (title.equals(""))//对象比较 title = JOptionPane.showInputDialog("Please supply a frame title:"); if (title == null) title = ""; setTitle(title); // set up file chooser that shows XML files final JFileChooser chooser = new JFileChooser(); chooser.setCurrentDirectory(new File(".")); chooser.setFileFilter(new FileNameExtensionFilter("XML files", "xml")); // set up menus JMenuBar menuBar = new JMenuBar();//创建新的菜单栏 setJMenuBar(menuBar); JMenu menu = new JMenu("File"); menuBar.add(menu); JMenuItem exportItem = new JMenuItem("Export preferences");//添加菜单项目 menu.add(exportItem); exportItem .addActionListener(event -> { if (chooser.showSaveDialog(PreferencesFrame.this) == JFileChooser.APPROVE_OPTION) //this引用 { try { savePreferences();//保存首选项 OutputStream out = new FileOutputStream(chooser .getSelectedFile()); node.exportSubtree(out); out.close(); } catch (Exception e) { e.printStackTrace();//捕获异常 } } }); JMenuItem importItem = new JMenuItem("Import preferences"); menu.add(importItem);//add方法 importItem .addActionListener(event -> { if (chooser.showOpenDialog(PreferencesFrame.this) == JFileChooser.APPROVE_OPTION) { try { InputStream in = new FileInputStream(chooser .getSelectedFile()); Preferences.importPreferences(in); in.close();//获得属性的设置 } catch (Exception e) { e.printStackTrace(); } } });
测试程序4
l 在elipse IDE中调试运行教材619页-622程序13-6,结合程序运行结果理解程序;
l 掌握基于JNLP协议的java Web Start应用程序的发布方法。
Calculator
package webstart; import java.io.BufferedReader; import java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; import java.io.FileNotFoundException; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.io.OutputStream; import java.io.PrintStream; import java.net.MalformedURLException; import java.net.URL; import javax.jnlp.BasicService; import javax.jnlp.FileContents; import javax.jnlp.FileOpenService; import javax.jnlp.FileSaveService; import javax.jnlp.PersistenceService; import javax.jnlp.ServiceManager; import javax.jnlp.UnavailableServiceException; import javax.swing.JFrame; import javax.swing.JMenu; import javax.swing.JMenuBar; import javax.swing.JMenuItem; import javax.swing.JOptionPane; /** * A frame with a calculator panel and a menu to load and save the calculator history. */ public class CalculatorFrame extends JFrame { private CalculatorPanel panel; public CalculatorFrame() { setTitle(); panel = new CalculatorPanel(); add(panel); JMenu fileMenu = new JMenu("File"); JMenuBar menuBar = new JMenuBar(); menuBar.add(fileMenu); setJMenuBar(menuBar); JMenuItem openItem = fileMenu.add("Open"); openItem.addActionListener(event -> open()); JMenuItem saveItem = fileMenu.add("Save"); saveItem.addActionListener(event -> save()); pack(); } /** * Gets the title from the persistent store or asks the user for the title if there is no prior * entry. */ public void setTitle() { try { String title = null; BasicService basic = (BasicService) ServiceManager.lookup("javax.jnlp.BasicService"); URL codeBase = basic.getCodeBase(); PersistenceService service = (PersistenceService) ServiceManager .lookup("javax.jnlp.PersistenceService"); URL key = new URL(codeBase, "title"); try { FileContents contents = service.get(key); InputStream in = contents.getInputStream(); BufferedReader reader = new BufferedReader(new InputStreamReader(in)); title = reader.readLine(); } catch (FileNotFoundException e) { title = JOptionPane.showInputDialog("Please supply a frame title:"); if (title == null) return; service.create(key, 100); FileContents contents = service.get(key); OutputStream out = contents.getOutputStream(true); PrintStream printOut = new PrintStream(out); printOut.print(title); } setTitle(title); } catch (UnavailableServiceException | IOException e) { JOptionPane.showMessageDialog(this, e); } } /** * Opens a history file and updates the display. */ public void open() { try { FileOpenService service = (FileOpenService) ServiceManager .lookup("javax.jnlp.FileOpenService"); FileContents contents = service.openFileDialog(".", new String[] { "txt" }); JOptionPane.showMessageDialog(this, contents.getName()); if (contents != null) { InputStream in = contents.getInputStream(); BufferedReader reader = new BufferedReader(new InputStreamReader(in)); String line; while ((line = reader.readLine()) != null) { panel.append(line); panel.append("\n"); } } } catch (UnavailableServiceException e) { JOptionPane.showMessageDialog(this, e); } catch (IOException e) { JOptionPane.showMessageDialog(this, e); } } /** * Saves the calculator history to a file. */ public void save() { try { ByteArrayOutputStream out = new ByteArrayOutputStream(); PrintStream printOut = new PrintStream(out); printOut.print(panel.getText()); InputStream data = new ByteArrayInputStream(out.toByteArray()); FileSaveService service = (FileSaveService) ServiceManager .lookup("javax.jnlp.FileSaveService"); service.saveFileDialog(".", new String[] { "txt" }, data, "calc.txt"); } catch (UnavailableServiceException e) { JOptionPane.showMessageDialog(this, e); } catch (IOException e) { JOptionPane.showMessageDialog(this, e); } } }
package webstart; import java.awt.*; import java.awt.event.*; import javax.swing.*; import javax.swing.text.*; /** A panel with calculator buttons and a result display. */ public class CalculatorPanel extends JPanel { private JTextArea display; private JPanel panel; private double result; private String lastCommand; private boolean start; /** Lays out the panel. */ public CalculatorPanel() { setLayout(new BorderLayout()); result = 0; lastCommand = "="; start = true; // add the display display = new JTextArea(10, 20); add(new JScrollPane(display), BorderLayout.NORTH); ActionListener insert = new InsertAction(); ActionListener command = new CommandAction(); // add the buttons in a 4 x 4 grid panel = new JPanel(); panel.setLayout(new GridLayout(4, 4)); addButton("7", insert); addButton("8", insert); addButton("9", insert); addButton("/", command); addButton("4", insert); addButton("5", insert); addButton("6", insert); addButton("*", command); addButton("1", insert); addButton("2", insert); addButton("3", insert); addButton("-", command); addButton("0", insert); addButton(".", insert); addButton("=", command); addButton("+", command); add(panel, BorderLayout.CENTER); } /** Gets the history text. @return the calculator history */ public String getText() { return display.getText(); } /** Appends a string to the history text. @param s the string to append */ public void append(String s) { display.append(s); } /** Adds a button to the center panel. @param label the button label @param listener the button listener */ private void addButton(String label, ActionListener listener) { JButton button = new JButton(label); button.addActionListener(listener); panel.add(button); } /** This action inserts the button action string to the end of the display text. */ private class InsertAction implements ActionListener { public void actionPerformed(ActionEvent event) { String input = event.getActionCommand(); start = false; display.append(input); } } /** This action executes the command that the button action string denotes. */ private class CommandAction implements ActionListener { public void actionPerformed(ActionEvent event) { String command = event.getActionCommand(); if (start) { if (command.equals("-")) { display.append(command); start = false; } else lastCommand = command; } else { try { int lines = display.getLineCount(); int lineStart = display.getLineStartOffset(lines - 1); int lineEnd = display.getLineEndOffset(lines - 1); String value = display.getText(lineStart, lineEnd - lineStart); display.append(" "); display.append(command); calculate(Double.parseDouble(value)); if (command.equals("=")) display.append("\n" + result); lastCommand = command; display.append("\n"); start = true; } catch (BadLocationException e) { e.printStackTrace(); } } } } /** Carries out the pending calculation. @param x the value to be accumulated with the prior result. */ public void calculate(double x) { if (lastCommand.equals("+")) result += x; else if (lastCommand.equals("-")) result -= x; else if (lastCommand.equals("*")) result *= x; else if (lastCommand.equals("/")) result /= x; else if (lastCommand.equals("=")) result = x; } }
实验2:GUI综合编程练习
练习1:采用GUI界面设计以下程序,并进行部署与发布:
l 编制一个程序,将身份证号.txt 中的信息读入到内存中;
l 按姓名字典序输出人员信息;
l 查询最大年龄的人员信息;
l 查询最小年龄人员信息;
l 输入你的年龄,查询身份证号.txt中年龄与你最近人的姓名、身份证号、年龄、性别和出生地;
l 查询人员中是否有你的同乡。
l 输入身份证信息,查询所提供身份证号的人员信息,要求输入一个身份证数字时,查询界面就显示满足查询条件的查询结果,且随着输入的数字的增多,查询匹配的范围逐渐缩小。
package 身份证; import java.io.BufferedReader; import java.io.File; import java.io.FileInputStream; import java.io.InputStreamReader; import java.io.FileNotFoundException; import java.io.IOException; import java.util.ArrayList; import java.util.Arrays; import java.util.Collections; import java.util.Scanner; import java.awt.*; import javax.swing.*; import java.awt.event.*; public class Main extends JFrame { private static ArrayListstudentlist; private static ArrayList list; private JPanel panel; private JPanel buttonPanel; private static final int DEFAULT_WITH = 900; private static final int DEFAULT_HEIGHT = 500; public Main() { studentlist = new ArrayList<>(); Scanner scanner = new Scanner(System.in); File file = new File("D:\\java\\身份证号.txt"); try { FileInputStream fis = new FileInputStream(file); BufferedReader in = new BufferedReader(new InputStreamReader(fis)); String temp = null; while ((temp = in.readLine()) != null) { Scanner linescanner = new Scanner(temp); linescanner.useDelimiter(" "); String name = linescanner.next(); String number = linescanner.next(); String sex = linescanner.next(); String age = linescanner.next(); String province = linescanner.nextLine(); Student student = new Student(); student.setName(name); student.setnumber(number); student.setsex(sex); int a = Integer.parseInt(age); student.setage(a); student.setprovince(province); studentlist.add(student); } } catch (FileNotFoundException e) { System.out.println("学生信息文件找不到"); e.printStackTrace(); } catch (IOException e) { System.out.println("学生信息文件读取错误"); e.printStackTrace(); } panel = new JPanel(); panel.setLayout(new BorderLayout()); JTextArea jt = new JTextArea(); panel.add(jt); add(panel, BorderLayout.NORTH); buttonPanel = new JPanel(); buttonPanel.setLayout(new GridLayout(1, 8)); JButton jButton = new JButton("字典排序"); JButton jButton1 = new JButton("年龄最大和年龄最小"); JLabel lab = new JLabel("查找你的同乡"); JTextField jt1 = new JTextField(); JLabel lab1 = new JLabel("查找与你年龄相近的人:"); JTextField jt2 = new JTextField(); JLabel lab2 = new JLabel("输入你的身份证号码:"); JTextField jt3 = new JTextField(); JButton jButton2 = new JButton("退出"); jButton.setBounds(900, 200,100, 90); jButton1.setBounds(50, 120, 90, 60); jt1.setBounds(900, 120, 100, 80); jt2.setBounds(800, 200, 100, 80); jt3.setBounds(450, 120, 80, 90); jButton2.setBounds(800,200, 60, 50); jButton.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { Collections.sort(studentlist); jt.setText(studentlist.toString()); } }); jButton1.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { int max = 0, min = 100; int j, k1 = 0, k2 = 0; for (int i = 1; i < studentlist.size(); i++) { j = studentlist.get(i).getage(); if (j > max) { max = j; k1 = i; } if (j < min) { min = j; k2 = i; } } jt.setText("年龄最大:" + studentlist.get(k1) + "年龄最小:" + studentlist.get(k2)); } }); jButton2.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { dispose(); System.exit(0); } }); jt1.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { String find = jt1.getText(); String text=""; String place = find.substring(0, 3); for (int i = 0; i < studentlist.size(); i++) { if (studentlist.get(i).getprovince().substring(1, 4).equals(place)) { text+="\n"+studentlist.get(i); jt.setText("老乡:" + text); } } } }); jt2.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { String yourage = jt2.getText(); int a = Integer.parseInt(yourage); int near = agenear(a); int value = a - studentlist.get(near).getage(); jt.setText("年龄相近:" + studentlist.get(near)); } }); jt3.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { list = new ArrayList<>(); Collections.sort(studentlist); String key = jt3.getText(); for (int i = 1; i < studentlist.size(); i++) { if (studentlist.get(i).getnumber().contains(key)) { list.add(studentlist.get(i)); jt.setText("你或许是:\n" + list); } } } }); buttonPanel.add(jButton); buttonPanel.add(jButton1); buttonPanel.add(lab); buttonPanel.add(jt1); buttonPanel.add(lab1); buttonPanel.add(jt2); buttonPanel.add(lab2); buttonPanel.add(jt3); buttonPanel.add(jButton2); add(buttonPanel, BorderLayout.SOUTH); setSize(DEFAULT_WITH, DEFAULT_HEIGHT); } public static int agenear(int age) { int min = 53, value = 0, k = 0; for (int i = 0; i < studentlist.size(); i++) { value = studentlist.get(i).getage() - age; if (value < 0) value = -value; if (value < min) { min = value; k = i; } } return k; } }
package 身份证; public class Student implements Comparable{ private String name; private String number ; private String sex ; private int age; private String province; public String getName() { return name; } public void setName(String name) { this.name = name; } public String getnumber() { return number; } public void setnumber(String number) { this.number = number; } public String getsex() { return sex ; } public void setsex(String sex ) { this.sex =sex ; } public int getage() { return age; } public void setage(int age) { // int a = Integer.parseInt(age); this.age= age; } public String getprovince() { return province; } public void setprovince(String province) { this.province=province ; } public int compareTo(Student o) { return this.name.compareTo(o.getName()); } public String toString() { return name+"\t"+sex+"\t"+age+"\t"+number+"\t"+province+"\n"; } }
package 身份证; import java.awt.*; import javax.swing.*; public class ButtonTest { public static void main(String[] args) { EventQueue.invokeLater(() -> { JFrame frame = new Main(); frame.setTitle("身份证"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setVisible(true); }); } }
练习2:采用GUI界面设计以下程序,并进行部署与发布
l 编写一个计算器类,可以完成加、减、乘、除的操作
l 利用计算机类,设计一个小学生100以内数的四则运算练习程序,由计算机随机产生10道加减乘除练习题,学生输入答案,由程序检查答案是否正确,每道题正确计10分,错误不计分,10道题测试结束后给出测试总分;
将程序中测试练习题及学生答题结果输出到文件,文件名为test.txt。
package S; import java.io.*; import java.io.PrintWriter; import java.util.Scanner; public class jisuan { public static void main(String[] args) { Scanner in = new Scanner(System.in); PrintWriter output = null; try { output = new PrintWriter("text.txt"); } catch (FileNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } int sum = 0; for (int i = 1; i <= 10; i++) { int a = (int) Math.round(Math.random() * 100); int b = (int) Math.round(Math.random() * 100); int m = (int) Math.round(Math.random() * 4); switch (m) { case 1: while (b == 0) { b = (int) Math.round(Math.random() * 100); } while (a % b != 0) { a = (int) Math.round(Math.random() * 100); } System.out.println(a + "/" + b + "="); int c1 = in.nextInt(); output.println(a + "/" + b + "=" + c1); if (c1 == a / b) { System.out.println("恭喜答案正确"); sum += 10; } else { System.out.println("抱歉,答案错误"); } break; case 2: System.out.println( a + "*" + b + "="); int c2 = in.nextInt(); output.println(a + "*" + b + "=" + c2); if (c2 == a * b) { System.out.println("恭喜答案正确"); sum += 10; } else { System.out.println("抱歉,答案错误"); } break; case 3: System.out.println( a + "+" + b + "="); int c3 = in.nextInt(); output.println(a + "+" + b + "=" + c3); if (c3 == a + b) { System.out.println("恭喜答案正确"); sum += 10; } else { System.out.println("抱歉,答案错误"); } break; case 4: while (a < b) { a = (int) Math.round(Math.random() * 100); } System.out.println( a + "-" + b + "="); int c4 = in.nextInt(); output.println(a + "-" + b + "=" + c4); if (c4 == a - b) { System.out.println("恭喜答案正确"); sum += 10; } else { System.out.println("抱歉,答案错误"); } break; } } System.out.println("成绩" + sum); output.println("成绩" + sum); output.close(); } }
package S; public class math{ private T a; private T b; public int add(int a, int b) { return a + b; } public int reduce(int a, int b) { return a - b; } public int multiplication(int a, int b) { return a * b; } public int division(int a, int b) { if (b != 0 && a % b == 0) return a / b; else return 0; } }
三、实验总结
本章我们学习的知识好像也不是特别难,但实际操作就完全不一样了,由于个人能力有限,在编写程序时候有借鉴别人的代码,虽然想在此基础上进行变化,但最终结果不尽人意,所以只能做到这个样子,而且测试程序也做不太出来,老是发现有错,所以这次实验感觉很不合格,得反省更改……