第一部分：理论知识学习部分
JAR文件：将.class文件压缩打包为.jar文件后，使用ZIP压缩格式，GUI界面程序就可以直接双击图标运行。
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命令格式：jar {ctxui} [vfm0Me] [jar-file] [manifest-file] [entry-point] [-C dir] files ...
⚫ Jar命令选项（教材581页表13-1）：
– -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
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。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。
创建一个包含清单的JAR文件：jar cfm MyArchive.jar manifest.mf com/*.class
要更新一个已有JAR文件的清单，则需要将增加的部分放置到一个文本文件中：
jar ufm MyArchive.jar manifest-additions.mf
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。
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，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：
1. 获得资源的Class对象。
2. 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。
3. 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。
1.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。
2.绝对资源名：如/corejava/title.txt
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
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");
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 = 300;
private static final int DEFAULT_HEIGHT = 300;
public ResourceTestFrame()
{
setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);//调整组件的大小
URL aboutURL = getClass().getResource("about.gif");//简单的文件或目录对象的引用
Image img = new ImageIcon(aboutURL).getImage();//根据指定的 URL 创建一个 ImageIcon
setIconImage(img);//设置要作为此窗口图标显示的图像
JTextArea textArea = new JTextArea();//一个显示纯文本的多行区域
InputStream stream = getClass().getResourceAsStream("about.txt");//表示字节输入流的所有类的超类，查找具有给定名称的资源
try (Scanner in = new Scanner(stream, "UTF-8"))
{
while (in.hasNext())//扫描器的输入中有另一个标记
textArea.append(in.nextLine() + "\n");//将给定文本追加到文档结尾
}
add(textArea);
}
}
将所生成的JAR文件移到另外一个不同的目录中
运行结果：
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()
{
//从属性中获取位置、大小和标题
String userDir = System.getProperty("user.home");//找出用户主目录
File propertiesDir = new File(userDir, ".corejava");
if (!propertiesDir.exists()) propertiesDir.mkdir();//创建此抽象路径名指定的目录。
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);
}
catch (IOException ex)
{
ex.printStackTrace();
}
int left = Integer.parseInt(settings.getProperty("left"));//能在 int 类型和 String 类型之间互相转换
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
// 如果没有标题，询问用户
String title = settings.getProperty("title");
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。
//添加指定的窗口侦听器，以从此窗口接收窗口事件
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(0);
}
});
实验结果：
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();
private Preferences node = root.node("/com/horstmann/corejava");
public PreferencesFrame()
{
// 从偏好获得位置、大小、标题
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);
// 如果没有标题，请询问用户
String title = node.get("title", "");
if (title.equals(""))
title = JOptionPane.showInputDialog("Please supply a frame title:");
if (title == null) title = "";
setTitle(title);
// 设置显示XML文件的文件选择器
final JFileChooser chooser = new JFileChooser();
chooser.setCurrentDirectory(new File("."));
chooser.setFileFilter(new FileNameExtensionFilter("XML files", "xml"));
// 设置菜单
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(0);
});
}
public void savePreferences()
{
node.putInt("left", getX());
node.putInt("top", getY());
node.putInt("width", getWidth());
node.putInt("height", getHeight());
node.put("title", getTitle());
}
}
实验结果：
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.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
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(0, 0,(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(900, 50, 400, 30);
text=new JTextArea(30,80);text.setBounds(50, 180, 700, 700);
text1=new JTextArea(1,30);text1.setBounds(900, 80, 400, 30);
text2=new JTextArea(30,80);text2.setBounds(900,180,700, 700);
text3=new JTextArea(30,80);text3.setBounds(420,100,200,40);
Button.addActionListener(new Action());Button.setBounds(50,50,300,40);
Button2.addActionListener(new Action1());Button2.setBounds(50,100,300,40);
Button3.addActionListener(new Action2());Button3.setBounds(650,100,120,40);
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 = 0; 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 = 0; 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, 0,100);
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=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;
}
}
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 = 0; 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=0,min=53,d_value=0,k=0;
for (int i = 0; i < Personlist.size(); i++)
{
d_value=Personlist.get(i).getage()-age;
if(d_value<0) 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(0, 0,(int)s.getWidth()/2,(int)s.getHeight()/2);
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[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 Demo() {
JPanel Panel = new JPanel();Panel.setLayout(null);
JLabel JLabel1=new JLabel("");JLabel1.setBounds(500, 800, 400, 30);JLabel1.setFont(new Font("Courier",Font.PLAIN,35));
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,35));
text1=new JTextArea(30,80);text1.setBounds(270, 50, 200, 50);text1.setFont(new Font("Courier",Font.PLAIN,35));
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("0");
if(i<10) {
int a = 1+(int)(Math.random() * 99);
int b = 1+(int)(Math.random() * 99);
int m= (int) Math.round(Math.random() * 3);
switch(m)
{
case 0:
while(a<b){ b = (int) Math.round(Math.random() * 100);a = (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 daan=text1.getText().toString().trim();
int a = Integer.parseInt(daan);
if(text1.getText()!="") {
if(list[i1]==a) sum+=10;
}
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=0;counter<10;counter++)
{
out.println(c[counter]+c1[counter]);
}
out.println("成绩"+sum);
out.close();
}
}
}
实验总结：通过这周自己的学习，学习了有关jar的相关知识，但是不理解的部分较多。