使用的教材:Java核心技术
Java核心技术第一章主要讲述Java的特性以及Java的发展史
第二章搭建开发环境,由于书比较老,对于现在也不是很适合,需要安装可以去百度搜索搭建Java环境的方法,现在的计算机越来越强大,环境目录都基本不用配置,应该说是傻瓜式操作。
然后就是介绍使用命令行和集成开发环境的使用,并给出代码运行。
命令行窗口并不能引起人的兴奋。所以又给出一个图形化应用程序—–图片查看器。
![](http://smk110.cn/wp-content/uploads/2020/05/image-12.png)
![](http://smk110.cn/wp-content/uploads/2020/05/image-13.png)
代码如下:
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1 import javax.swing.*; 2 import java.awt.*; 3 import java.awt.event.ActionEvent; 4 import java.awt.event.ActionListener; 5 import java.io.File; 6 7 public class ImageViewer { 8 public static void main(String[] args) { 9 EventQueue.invokeLater(new Runnable() { 10 @Override 11 public void run() { 12 JFrame frame = new ImageViewerFrame(); 13 frame.setTitle("ImageViewer"); 14 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 15 frame.setVisible(true); 16 } 17 }); 18 } 19 } 20 class ImageViewerFrame extends JFrame{ 21 private JLabel label; 22 private JFileChooser chooser; 23 private static final int DEFAULT_WIDTH = 300; 24 private static final int DEFAULT_HEIGHT = 400; 25 26 public ImageViewerFrame() throws HeadlessException { 27 setSize(DEFAULT_WIDTH,DEFAULT_WIDTH); 28 //use a lable to display the images 29 label = new JLabel(); 30 add(label); 31 32 //set up the file chooser 33 chooser = new JFileChooser(); 34 chooser.setCurrentDirectory(new File(".")); 35 36 //set up the menu bar 37 JMenuBar menuBar = new JMenuBar(); 38 setJMenuBar(menuBar); 39 40 JMenu menu = new JMenu("File"); 41 menuBar.add(menu); 42 43 JMenuItem openItem = new JMenuItem("open"); 44 menu.add(openItem); 45 46 openItem.addActionListener(new ActionListener() { 47 @Override 48 public void actionPerformed(ActionEvent actionEvent) { 49 //show file chooser dialog 50 int result = chooser.showOpenDialog(null); 51 52 //if file selected,set it as icon of the label 53 if (result == JFileChooser.APPROVE_OPTION){ 54 String name = chooser.getSelectedFile().getPath(); 55 56 label.setIcon(new ImageIcon(name)); 57 } 58 } 59 }); 60 JMenuItem exitItem = new JMenuItem("Exit"); 61 menu.add(exitItem); 62 exitItem.addActionListener(new ActionListener() { 63 @Override 64 public void actionPerformed(ActionEvent actionEvent) { 65 System.exit(0); 66 } 67 }); 68 69 } 70 }
代码看不懂无所谓,先敲上去,运行之后,感受一番,相信会有更大的动力。
然后还演示了Applet的使用,很遗憾,这个API已经被淘汰掉了
还是把代码放上来:WelcomeApplet.java
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1 2 import java.awt.*; 3 import java.awt.event.*; 4 import java.net.*; 5 import javax.swing.*; 6 7 public class WelcomeApplet extends JApplet{ 8 public void init(){ 9 EventQueue.invokeLater(new Runnable() { 10 @Override 11 public void run() { 12 setLayout(new BorderLayout()); 13 JLabel label = new JLabel(getParameter("geeting"),SwingConstants.CENTER); 14 label.setFont(new Font("Serif",Font.BOLD,18)); 15 add(label,BorderLayout.CENTER); 16 JPanel panel = new JPanel(); 17 18 JButton cayButton = new JButton("Cay Horstman"); 19 cayButton.addActionListener(makeAction("http://horstman.com")); 20 panel.add(cayButton); 21 22 JButton garyButton = new JButton("Gray Cornell"); 23 garyButton.addActionListener(makeAction("mailto:gray_cornell@apress.com")); 24 panel.add(garyButton); 25 26 add(panel,BorderLayout.SOUTH); 27 } 28 }); 29 } 30 private ActionListener makeAction(final String urlString){ 31 return new ActionListener() { 32 @Override 33 public void actionPerformed(ActionEvent actionEvent) { 34 try { 35 getAppletContext().showDocument(new URL(urlString)); 36 }catch (MalformedURLException e){ 37 e.printStackTrace(); 38 } 39 } 40 }; 41 } 42 }
WelcomeApplet.html
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1 <html> 2 <head> 3 <meta charset="UTF-8"> 4 <title>WelcomeApplet</title> 5 </head> 6 <body> 7 <hr/> 8 <p> 9 This applet is from the book 10 <a href="http://www.horstman.com/corejava.html">Core Java</a> 11 by <em>Cay Horstman</em> and <em>Gary Cornel</em> 12 </p> 13 <applet code="WelcomeApplet.class" width="400" height="200"> 14 <param name="greeting" value="Welcome to Core Java!"> 15 </applet> 16 <hr/> 17 <p><a href="WelcomeApplet.java">The source.</a></p> 18 19 </body> 20 </html>