实验十五 GUI编程练习与应用程序部署
实验时间 2018-12-6
1、实验目的与要求
(1)一个JAR文件既可以包含类文件，也可以包含诸如图像和声音这些其他类型的文件。
创建一个新的JAR文件应该使用的常见命令格式：jar cvf JARFileName File1 File2.....
除类文件、图像和其它资源外，每个JAR文件包含一个用于描述归档特征的清单文件，清单文件被命名为MANIFEST.MF。
复杂的清单文件可能包含更多条目，这些清单条目被分成多个节；第一个节被称为主节，作用于整个JAR文件；随后的条目用来指定已命名条目的属性，这些已命名条目可以是某个文件、包或者URL，但都必须是起始于名为Name的条目，节与节之间用空行隔开。
在applet和应用程序中使用的类通常需要使用一些相关的数据文件：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。（在JAVA中，这些关联的文件被称为资源）
类加载器知道如何搜索类文件，直到在类路径、存档文件和web服务器上找到为止。
(2) 属性映射是一种存储键/值对的数据结构。
其有以下三个特性：键和值是字符串、映射可以很容易的存入文件以及从文件加载、有一个二级表保存默认值。
实现属性映射的JAVA类名为Properties；属性映射对于指定程序的配置选项很有用。
使用属性文件的缺点：有些操作系统没有主目录的概念，所以很难找到一个统一的配置文件位置；关于配置文件的命名没有标准约定，用户安装多个JAVA应用时，就更容易发生命名冲突。
有些操作系统有一个存储配置信息的中心存储库，存储库的各个节点分别有一个单独的键/值对表，可以用来存储数值、字符串或字节数组，但不能存储可串行化的对象。
注意，读取信息时必须指定一个默认值，以防止没有可用的存储库数据。
(3) 定义一个接口（或者，也可以定义一个超类），其中包含服务的各个实例应当提供的方法。
实现类可以放在任意包中，而不一定是服务接口所在的包，每个实现类必须有一个无参数构造器。
Applet就是一个扩展了java.applet.Applet类的Java类。
要执行applet，需要完成以下三个步骤：将Java源文件编译为类文件；将类打包到一个JAR文件中；创建一个HTML文件，告诉浏览器首先加载那个类文件，以及如何设定applet的大小。
Applet查看器程序的命令行参数是HTML文件名，而不是类文件。
参数总是作为字符串返回，如果需要数值类型，则需要将字符串转换为数值。
Applet可以处理图像和音频；要用相对URL指定图像和音频文件的位置。
Applet在浏览器或在applet查看器中运行；一个页面可以包含多个applet。
(4) 要想访问与某个特定键关联的信息，需要调用get方法；这个方法将返回一个FileContens对象，通过这个对象可以对键数据进行读写。
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；
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");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
});
}
} /**
* A frame that loads image and text resources.
*/
class ResourceTestFrame extends JFrame
{
private static final int DEFAULT_WIDTH = ;
private static final int DEFAULT_HEIGHT = ; public ResourceTestFrame()
{
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文件
setIconImage(img); JTextArea textArea = new JTextArea();
InputStream stream = getClass().getResourceAsStream("about.txt");
try (Scanner in = new Scanner(stream, "UTF-8"))//将资源文件和类文件放在同一个目录中，还可以将他放在子目录中
{
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；
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 = ;
private static final int DEFAULT_HEIGHT = ; private File propertiesFile;
private Properties settings; public PropertiesFrame()
{
// get position, size, title from properties String userDir = System.getProperty("user.home");//为程序属性提供默认值
File propertiesDir = new File(userDir, ".corejava");
if (!propertiesDir.exists()) propertiesDir.mkdir();
propertiesFile = new File(propertiesDir, "program.properties"); Properties defaultSettings = new Properties();
defaultSettings.setProperty("left", "");
defaultSettings.setProperty("top", "");
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);//从文件加载属性
}
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); // 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()
{
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();
}
});
}
}
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；
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 = ;
private static final int DEFAULT_HEIGHT = ;
private Preferences root = Preferences.userRoot();//返回调用程序的首选项根节点
private Preferences node = root.node("/com/horstmann/corejava"); public PreferencesFrame()
{
// get position, size, title from preferences int left = node.getInt("left", );
int top = node.getInt("top", );
int width = node.getInt("width", DEFAULT_WIDTH);
int height = node.getInt("height", DEFAULT_HEIGHT);
setBounds(left, top, width, height); // if no title given, ask user String title = node.get("title", "");
if (title.equals(""))
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();
setJMenuBar(menuBar);
JMenu menu = new JMenu("File");
menuBar.add(menu); JMenuItem exportItem = new JMenuItem("Export preferences");
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();
});
} public void savePreferences()
{
node.putInt("left", getX());
node.putInt("top", getY());
node.putInt("width", getWidth());
node.putInt("height", getHeight());
node.put("title", getTitle());
}
}
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.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, );
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 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.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 = ;
lastCommand = "=";
start = true; // add the display display = new JTextArea(, ); 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(, )); addButton("", insert);
addButton("", insert);
addButton("", insert);
addButton("/", command); addButton("", insert);
addButton("", insert);
addButton("", insert);
addButton("*", command); addButton("", insert);
addButton("", insert);
addButton("", insert);
addButton("-", command); addButton("", 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 - );
int lineEnd = display.getLineEndOffset(lines - );
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：
编制一个程序，将身份证号.txt 中的信息读入到内存中；
按姓名字典序输出人员信息；
查询最大年龄的人员信息；
查询最小年龄人员信息；
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；
查询人员中是否有你的同乡。
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 身份查询;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Toolkit;
import javax.swing.JFrame;
public class Out {
public static void main (String args[])
{
Toolkit t=Toolkit.getDefaultToolkit();
Dimension s=t.getScreenSize();
EventQueue.invokeLater(() -> {
JFrame frame = new Main1();
frame.setBounds(, ,(int)s.getWidth(),(int)s.getHeight());
frame.setTitle("身份查询系统");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
});
}
}
package 身份查询;
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 身份查询;
import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.*;
import java.util.Timer;
import javax.swing.*;
public class Main1 extends JFrame
{
private static ArrayList<Person> Personlist;
Scanner scanner = new Scanner(System.in);
File file = new File("F:\\身份证号.txt");
private JPanel Panel;
private JLabel JLabel1;
private JButton Button,Button2,Button3;
private JTextArea text,text1,text2,text3;
boolean tru=true;
public Main1() {
Panel = new JPanel();Panel.setLayout(null);
Button = new JButton("1:按姓名字典序输出人员信息");
Button2 = new JButton("2:查询最大年龄与最小年龄人员信息");
Button3 = new JButton("查询相近年龄");
JLabel1 = new JLabel("输入身份证号或者地址查询");JLabel1.setBounds(, , , );
text=new JTextArea(,);text.setBounds(, , , );
text1=new JTextArea(,);text1.setBounds(, , , );
text2=new JTextArea(,);text2.setBounds(,,, );
text3=new JTextArea(,);text3.setBounds(,,,);
Button.addActionListener(new Action());Button.setBounds(,,,);
Button2.addActionListener(new Action1());Button2.setBounds(,,,);
Button3.addActionListener(new Action2());Button3.setBounds(,,,);
Panel.add(JLabel1);
Panel.add(Button);
Panel.add(Button2);
Panel.add(Button3);
Panel.add(text);
Panel.add(text2);
Panel.add(text1);
Panel.add(text3);
add(Panel);
Timer timer = new Timer();
TimerTask timeTask=new TimerTask() {
@Override
public void run()
{
// TODO Auto-generated method stub
text2.setText(null);
String place=text1.getText().toString().trim();
for (int i = ; i <Personlist.size(); i++)
{
String Str=(String)Personlist.get(i).getbirthplace();
if(Str.contains(place)&&!place.equals(""))
{
text2.append(Personlist.get(i).toString());
}
}
for (int i = ; i <Personlist.size(); i++)
{
String Str=(String)Personlist.get(i).getID();
if(Str.contains(place)&&!place.equals(""))
{
text2.append(Personlist.get(i).toString());
}
}
}
};timer.schedule(timeTask, ,);
Personlist = new ArrayList<>();
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();
}
}
private class Action implements ActionListener
{
public void actionPerformed(ActionEvent event)
{
text.setText(null);
Collections.sort(Personlist);
text.append(Personlist.toString());
}
}
private class Action1 implements ActionListener
{
public void actionPerformed(ActionEvent event)
{
text.setText(null);
int max=,min=;int j,k1 = ,k2=;
for(int i=;i<Personlist.size();i++)
{
j=Personlist.get(i).getage();
if(j>max)
{
max=j;
k1=i;
}
if(j<min)
{
min=j;
k2=i;
}
}
text.append("年龄最大： "+Personlist.get(k1)+"\n"+"年龄最小： "+Personlist.get(k2));
}
}
private class Action2 implements ActionListener
{
public void actionPerformed(ActionEvent event)
{
text.setText(null);
int a = Integer.parseInt(text3.getText().toString().trim());
int d_value=a-Personlist.get(agenear(a)).getage();
for (int i = ; i < Personlist.size(); i++)
{
int p=Personlist.get(i).getage()-a;
if(p==d_value||-p==d_value) text.append(Personlist.get(i).toString());
}
}
}
public static int agenear(int age) {
int j=,min=,d_value=,k=;
for (int i = ; i < Personlist.size(); i++)
{
d_value=Personlist.get(i).getage()-age;
if(d_value<) d_value=-d_value;
if (d_value<min)
{
min=d_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
编写一个计算器类，可以完成加、减、乘、除的操作
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 计算器;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Toolkit;
import javax.swing.JFrame;
public class New {
public static void main (String args[])
{
Toolkit t=Toolkit.getDefaultToolkit();
Dimension s=t.getScreenSize();
EventQueue.invokeLater(() -> {
JFrame frame = new Demo();
frame.setBounds(, ,(int)s.getWidth()/,(int)s.getHeight()/);
frame.setTitle("计算器");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
});
}
}
package 计算器;
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 Demo extends JFrame {
private String[] c=new String[];
private String[] c1=new String[];
private int[] list=new int[];
int i=,i1=,sum = ;
private PrintWriter out = null;
private JTextArea text,text1;
private int counter;
public Demo() {
JPanel Panel = new JPanel();Panel.setLayout(null);
JLabel JLabel1=new JLabel("");JLabel1.setBounds(, , , );JLabel1.setFont(new Font("Courier",Font.PLAIN,));
JButton Button = new JButton("生成题目");Button.setBounds(,,,);Button.setFont(new Font("Courier",Font.PLAIN,)); Button.addActionListener(new Action());
JButton Button2 = new JButton("确定答案");Button2.setBounds(,,,);Button2.setFont(new Font("Courier",Font.PLAIN,));Button2.addActionListener(new Action1());
JButton Button3 = new JButton("读出文件");Button3.setBounds(,,,);Button3.setFont(new Font("Courier",Font.PLAIN,));Button3.addActionListener(new Action2());
text=new JTextArea(,);text.setBounds(, , , );text.setFont(new Font("Courier",Font.PLAIN,));
text1=new JTextArea(,);text1.setBounds(, , , );text1.setFont(new Font("Courier",Font.PLAIN,));
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<) {
int a = +(int)(Math.random() * );
int b = +(int)(Math.random() * );
int m= (int) Math.round(Math.random() * );
switch(m)
{
case :
while(a<b){ b = (int) Math.round(Math.random() * );a = (int) Math.round(Math.random() * ); }
c[i]=(i+":"+a+"/"+b+"=");
list[i]=Math.floorDiv(a, b);
text.setText(i+":"+a+"/"+b+"=");
i++;
break;
case :
c[i]=(i+":"+a+"*"+b+"=");
list[i]=Math.multiplyExact(a, b);
text.setText(i+":"+a+"*"+b+"=");
i++;
break;
case :
c[i]=(i+":"+a+"+"+b+"=");
list[i]=Math.addExact(a, b);
text.setText(i+":"+a+"+"+b+"=");
i++;
break ;
case :
while(a<=b){ b = (int) Math.round(Math.random() * );a = (int) Math.round(Math.random() * ); }
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<) {
text.setText(null);
String daan=text1.getText().toString().trim();
int a = Integer.parseInt(daan);
if(text1.getText()!="") {
if(list[i1]==a) sum+=;
}
c1[i1]=daan;
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=;counter<;counter++)
{
out.println(c[counter]+c1[counter]);
}
out.println("成绩"+sum);
out.close();
}
}
}
实验总结：本周学习了JAR文件及创建和执行等等，通过老师讲解JAR和书上内容的学习更好地了解掌握JAR，然而本周的实验作业有难度，在编程写代码时还是存在困难与问题，只有多看代码多解释代码的练习才可以。