徐思201771010132《面向对象程序设计（java）》第十五周学习总结
一、理论知识部分
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。.jar文件（Java归档）既可以包含类文件，也可以包含诸如图像和声音这些其它类型的文件。JAR文件是压缩的，它使用ZIP压缩格式。
jar命令格式： jar {ctxui} [vfm0Me] [jar-file] [manifest-file] [entry-point] [-C dir] files ...
Jar命令选项：-c 创建一个新的或者空的存档文件并加入文件。 -C 暂时改变到指定的目录。 -e 在清单文件中创建一个条目。 -f 将JAR文件名指定为第二个命令行参数。 -i 为指定的JAR文件产生索引信息。 -m 将一个清单文件（manifest）添加到JAR文件中。 -M 不产生所有项的清单文件（manifest）。 -t 列出存档内容的列表。 -u 更新已存在的JAR文件。 -v 生成详细的输出结果。 -x 解压存档中的命名的（或所有的〕文件。 -0 只存储方式，不用ZIP压缩格式。
创建JAR文件：jar cf jar-file input-file(s) c---want to Create a JAR file.
查看JAR文件：jar tf jar-file t---want to view the Table of contents of the JAR file.
提取JAR文件：jar xf jar-file [archived-file(s)] x---want to extract files from the JAR archive.
更新JAR文件：jar uf jar-file input-file(s) u---want to update an existing JAR file.
索引JAR文件：jar i jar-file i---index an existing JAR file.
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。
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。
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。
类加载器知道如何搜索类文件，直到在类路径、 存档文件或Web服务器上找到为止。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。
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。
将Java包密封(Seal)可保证不会有其它的类加入到其中。如果在代码中使用了包可见的类、方法和字段，就可能希望密封包。如果不密封，其它类就有可能放在这个包中，进而访问包可见的特性。
要想密封一个包，需要将包中的所有类放到一个JAR文件。在默认情况下，JAR文件中的包是没有密封的。
要想密封JAR文件中的所有包，可以在清单文件的主节中加入下面一行：Sealed: true。要想密封单独的包，可以通过在JAR文件的清单文件的清单中增加一节，如：Name: com/mycompany/util/ Sealed: true Name: com/mycompany/misc/ Sealed: false
应用首选项的存储：一般有两种方法：将配置信息存储在属性文件中；将配置信息存储在中心知识库。
属性映射常被用来存放配置信息，属性映射是一种存储键/值对的数据结构。属性映射有三个特性：键和值都是字符串；键/值对易于写入文件或从文件读出； 用二级表存放默认值。
Properties类能够简化读取和保存配置信息的过程，但使用属性文件存在下列不足：配置文件无统一存放位置；无标准配置文件命名规则，当用户安装多个 Java应用程序时，会增加配置文件名冲突可能性。
二、实验部分
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。
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);// 设置用户在窗体上发起 "close" 时默认执行的操作。 frame.setVisible(true);// 设置窗口可见 }); } } /** * A frame that loads image and text resources. */ class ResourceTestFrame extends JFrame { private static final int DEFAULT_WIDTH = 300; private static final int DEFAULT_HEIGHT = 300; public ResourceTestFrame() { setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);// 调整组件大小 URL aboutURL = getClass().getResource("about.gif");// 利用about.gif图像文件制作图标 Image img = new ImageIcon(aboutURL).getImage(); setIconImage(img);// 设置要作为窗口图标显示的图像 JTextArea textArea = new JTextArea(); InputStream stream = getClass().getResourceAsStream("about.txt");// 读取about.txt文件 try (Scanner in = new Scanner(stream, "UTF-8")) { while (in.hasNext()) textArea.append(in.nextLine() + "\n"); } add(textArea); } }
测试程序2
l 在elipse IDE中调试运行教材583页-584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(() -> { 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; private Properties settings; public PropertiesFrame() { // get position, size, title from properties String userDir = System.getProperty("user.home");// 获取指定键指示的系统属性 File propertiesDir = new File(userDir, ".corejava"); if (!propertiesDir.exists()) propertiesDir.mkdir(); propertiesFile = new File(propertiesDir, "program.properties"); Properties defaultSettings = new Properties();// 创建一个无默认值的空属性列表。 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);// 从输入流中读取属性列表（键和元素对） } catch (IOException ex) { 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);// 移动组件并调整其大小 // 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);// 将此窗体的标题设置为指定的字符串 addWindowListener(new WindowAdapter() { public void windowClosing(WindowEvent event) { settings.setProperty("left", "" + getX());// 返回组件原点的当前 x 坐标 settings.setProperty("top", "" + getY());// 返回组件原点的当前 y 坐标 settings.setProperty("width", "" + getWidth());// 返回组件的当前宽度 settings.setProperty("height", "" + getHeight());// 返回组件的当前高度 settings.setProperty("title", getTitle());// 获得窗体的标题 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);// 设置用户在窗体上发起 "close" 时默认执行的操作 frame.setVisible(true);//显示窗口 }); } } /** * 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();// 返回调用用户的根首选项节点 private Preferences node = root.node("/com/horstmann/corejava"); 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);// 移动组件并调整其大小 // if no title given, ask user String title = node.get("title", "");// 返回与此首选项节点中指定键相关联的值 if (title.equals("")) title = JOptionPane.showInputDialog("Please supply a frame title:");// 显示请求用户输入的问题消息对话框 if (title == null) title = ""; setTitle(title);// 将此窗体的标题设置为指定的字符串 // set up file chooser that shows XML files final JFileChooser chooser = new JFileChooser();// 构造一个指向用户默认目录的 JFileChooser chooser.setCurrentDirectory(new File("."));// 设置当前目录 chooser.setFileFilter(new FileNameExtensionFilter("XML files", "xml"));// 设置当前文件过滤器 // set up menus JMenuBar menuBar = new JMenuBar();// 创建新的菜单栏 setJMenuBar(menuBar);// 设置此窗体的菜单栏 JMenu menu = new JMenu("File");// 构造一个新 JMenu，用提供的字符串作为其文本 menuBar.add(menu); JMenuItem exportItem = new JMenuItem("Export preferences");// 创建带有指定文本的 JMenuItem menu.add(exportItem); exportItem.addActionListener(event -> { if (chooser.showSaveDialog(PreferencesFrame.this) == JFileChooser.APPROVE_OPTION) { try { savePreferences(); OutputStream out = new FileOutputStream(chooser.getSelectedFile()); node.exportSubtree(out); out.close(); } catch (Exception e) { e.printStackTrace(); } } }); JMenuItem importItem = new JMenuItem("Import preferences"); menu.add(importItem); importItem.addActionListener(event -> { if (chooser.showOpenDialog(PreferencesFrame.this) == JFileChooser.APPROVE_OPTION) { try { InputStream in = new FileInputStream(chooser.getSelectedFile()); Preferences.importPreferences(in); in.close(); } catch (Exception e) { e.printStackTrace(); } } }); JMenuItem exitItem = new JMenuItem("Exit"); menu.add(exitItem); exitItem.addActionListener(event -> { savePreferences(); System.exit(0); }); } public void savePreferences() { node.putInt("left", getX());// 返回组件原点的当前 x 坐标 node.putInt("top", getY());// 返回组件原点的当前 y 坐标 node.putInt("width", getWidth());// 返回组件的当前宽度 node.putInt("height", getHeight());// 返回组件的当前高度 node.put("title", getTitle());// 返回组件的当前高度 } }
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。
package webstart; import java.awt.*; import javax.swing.*; /** * A calculator with a calculation history that can be deployed as a Java Web * Start application. * * @version 1.04 2015-06-12 * @author Cay Horstmann */ public class Calculator { public static void main(String[] args) { EventQueue.invokeLater(() -> { CalculatorFrame frame = new CalculatorFrame(); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setVisible(true); }); } }
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.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);//设置此窗体的菜单栏 JMenuItem openItem = fileMenu.add("Open"); openItem.addActionListener(event -> open()); JMenuItem saveItem = fileMenu.add("Save"); saveItem.addActionListener(event -> save()); pack();//调整此窗口的大小 } /** * 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());// 构造一个组件之间没有间距的新边框布局 result = 0; lastCommand = "="; start = true; // add the display display = new JTextArea(10, 20);// 构造具有10行10列的新的空 TextArea 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));// 创建4行4列的网格布局 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
按实验十四分组名单，组内讨论完成以下编程任务：
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 ID; import java.awt.*; import javax.swing.*; /** * @version 1.34 2015-06-12 * @author Cay Horstmann */ public class button { 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); }); } }
package ID; public class Person implements Comparable<Person> { private String name; private String ID; private int age; private String sex; private String birthplace; public String getname() { return name; } public void setname(String name) { this.name = name; } public String getID() { return ID; } public void setID(String ID) { this.ID = ID; } public int getage() { return age; } public void setage(int age) { this.age = age; } public String getsex() { return sex; } public void setsex(String sex) { this.sex = sex; } public String getbirthplace() { return birthplace; } public void setbirthplace(String birthplace) { this.birthplace = birthplace; } public int compareTo(Person o) { return this.name.compareTo(o.getname()); } public String toString() { return name + "\t" + sex + "\t" + age + "\t" + ID + "\t" + birthplace + "\n"; } }
package ID; 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.*; import java.awt.*; import javax.swing.*; import java.awt.event.*; public class Main extends JFrame { private static ArrayList<Person> personlist; private static ArrayList<Person> list; private JPanel panel; private JPanel buttonPanel; private static final int DEFAULT_WIDTH = 600; private static final int DEFAULT_HEIGHT = 300; public Main() { personlist = new ArrayList<>(); Scanner scanner = new Scanner(System.in); File file = new File("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 ID = linescanner.next(); String sex = linescanner.next(); String age = linescanner.next(); String place = linescanner.nextLine(); Person Person = new Person(); Person.setname(name); Person.setID(ID); Person.setsex(sex); int a = Integer.parseInt(age); Person.setage(a); Person.setbirthplace(place); personlist.add(Person); } } catch (FileNotFoundException e) { System.out.println("查找不到信息"); e.printStackTrace(); } catch (IOException e) { System.out.println("信息读取有误"); e.printStackTrace(); } JPanel panel = new JPanel(); panel.setLayout(new BorderLayout()); JTextArea jt = new JTextArea(); panel.add(jt); add(panel, BorderLayout.CENTER); JPanel buttonPanel = new JPanel(); buttonPanel.setLayout(new GridLayout(1, 7)); 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("你的老乡"); JTextField jt1 = new JTextField(); JLabel lab1 = new JLabel("查找年龄相近的："); 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(110, 90, 40, 50); jButton1.setBounds(110, 90, 40, 50); jt1.setBounds(110, 90, 40, 50); jt2.setBounds(110, 90, 40, 50); jt3.setBounds(110, 90, 40, 50); jButton2.setBounds(110, 90, 40, 50); jButton.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { Collections.sort(personlist); jt.setText(personlist.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 < personlist.size(); i++) { j = personlist.get(i).getage(); if (j > max) { max = j; k1 = i; } if (j < min) { min = j; k2 = i; } } jt.setText("年龄最大：" + personlist.get(k1) + "年龄最小：" + personlist.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 < personlist.size(); i++) { if (personlist.get(i).getbirthplace().substring(1, 4).equals(place)) { text += "\n" + personlist.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 - personlist.get(near).getage(); jt.setText("年龄相近：" + personlist.get(near)); } }); jt3.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { list = new ArrayList<>(); Collections.sort(personlist); String key = jt3.getText(); for (int i = 1; i < personlist.size(); i++) { if (personlist.get(i).getID().contains(key)) { list.add(personlist.get(i)); jt.setText("你可能是：\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_WIDTH, DEFAULT_HEIGHT); } public static int agenear(int age) { int min = 53, value = 0, k = 0; for (int i = 0; i < personlist.size(); i++) { value = personlist.get(i).getage() - age; if (value < 0) value = -value; if (value < min) { min = value; k = i; } } return k; } }
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；
l 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 math; import java.awt.Dimension; import java.awt.EventQueue; import java.awt.Toolkit; import javax.swing.JFrame; public class math { public static void main(String args[]) { Toolkit t = Toolkit.getDefaultToolkit(); Dimension s = t.getScreenSize(); EventQueue.invokeLater(() -> { JFrame frame = new main(); frame.setBounds(0, 0, (int) s.getWidth() / 2, (int) s.getHeight() / 2); frame.setTitle("算术测试"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setVisible(true); }); } }
package math; import java.awt.Font; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.io.FileNotFoundException; import java.io.PrintWriter; import java.util.Collections; import java.util.Scanner; import javax.swing.*; import java.math.*; public class main extends JFrame { private String[] c = new String[10]; private String[] c1 = new String[10]; private int[] list = new int[10]; int i = 0, i1 = 0, sum = 0; private PrintWriter out = null; private JTextArea text, text1; private int counter; public main() { JPanel Panel = new JPanel(); Panel.setLayout(null); JLabel JLabel1 = new JLabel(""); JLabel1.setBounds(500, 800, 400, 30); JLabel1.setFont(new Font("Courier", Font.PLAIN, 20)); JButton Button = new JButton("生成题目"); Button.setBounds(50, 150, 150, 50); Button.setFont(new Font("Courier", Font.PLAIN, 20)); Button.addActionListener(new Action()); JButton Button2 = new JButton("确定答案"); Button2.setBounds(300, 150, 150, 50); Button2.setFont(new Font("Courier", Font.PLAIN, 20)); Button2.addActionListener(new Action1()); JButton Button3 = new JButton("读出文件"); Button3.setBounds(500, 150, 150, 50); Button3.setFont(new Font("Courier", Font.PLAIN, 20)); Button3.addActionListener(new Action2()); text = new JTextArea(30, 80); text.setBounds(30, 50, 200, 50); text.setFont(new Font("Courier", Font.PLAIN, 30)); text1 = new JTextArea(30, 80); text1.setBounds(270, 50, 200, 50); text1.setFont(new Font("Courier", Font.PLAIN, 30)); Panel.add(text); Panel.add(text1); Panel.add(Button); Panel.add(Button2); Panel.add(Button3); Panel.add(JLabel1); add(Panel); } private class Action implements ActionListener { public void actionPerformed(ActionEvent event) { text1.setText(""); if (i <= 10) { int a = (int) Math.round(Math.random() * 100); int b = (int) Math.round(Math.random() * 100); int m = (int) Math.round(Math.random() * 3); switch (m) { case 0: while (a % b != 0) { a = (int) Math.round(Math.random() * 100); } while (b == 0) { b = (int) Math.round(Math.random() * 100); } c[i] = (i + ":" + a + "/" + b + "="); list[i] = Math.floorDiv(a, b); text.setText(i + ":" + a + "/" + b + "="); i++; break; case 1: c[i] = (i + ":" + a + "*" + b + "="); list[i] = Math.multiplyExact(a, b); text.setText(i + ":" + a + "*" + b + "="); i++; break; case 2: c[i] = (i + ":" + a + "+" + b + "="); list[i] = Math.addExact(a, b); text.setText(i + ":" + a + "+" + b + "="); i++; break; case 3: while (a < b) { b = (int) Math.round(Math.random() * 100); a = (int) Math.round(Math.random() * 100); } c[i] = (i + ":" + a + "-" + b + "="); text.setText(i + ":" + a + "-" + b + "="); list[i] = Math.subtractExact(a, b); i++; break; } } } } private class Action1 implements ActionListener { public void actionPerformed(ActionEvent event) { if (i < 10) { text.setText(null); String z = text1.getText().toString().trim(); int a = Integer.parseInt(z); if (text1.getText() != "") { if (list[i1] == a) sum += 10; } c1[i1] = z; i1++; } } } private class Action2 implements ActionListener { public void actionPerformed(ActionEvent event) { try { out = new PrintWriter("text.txt"); } catch (FileNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } for (int counter = 0; counter < 10; counter++) { out.println(c[counter] + c1[counter]); } out.println("成绩" + sum); out.close(); } } }
三、实验总结
通过这次实验，我了解了JAR文件的创建方法，Properties类中常用的方法。这次编程难度较大，很多是借鉴的其他同学的。
