Java Swing快速构建窗体应用程序

　　以前接触java感觉其在桌面开发上,总是不太方便,没有一个好的拖拽界面布局工具,可以快速构建窗体. 最近学习了一下NetBeans IDE 8.1,感觉其窗体设计工具还是很不错的 , 就尝试一下做了一个窗体应用程序. 总体下来,感觉和winform开发相差也不大,只是一些具体的设置或者语法有些差异,可以通过查阅相关资料进行掌握:

1 应用结构

新建一个java应用程序JavaApp,并创建相关的包及文件,其中简单实现了一个登录界面(JDBC 访问MYSQL数据库),登录成功后跳转到主界面.在主界面上单击菜单,可以打开子窗体.java swing自带的JTabbedPane没有显示关闭按钮的功能,这里在com.mkmis.controls包下自定义了一个TabbedPane控件,可以实现带关闭按钮的页签面板.应用结构如下图所示:

2 登陆界面设计

在IDE中新建一个Login的JFrame窗体,单击[设计]视图,可以将组件面板中的相关控件拖放到界面上,和Vistual Studio的操作差别不大,就是界面显示效果较差,不及Vistual Studio.用户名文本框用的文本字段,密码框用的是口令字段控件.登录和退出按钮用的是按钮控件.

设计完成后,单击运行按钮,界面效果如下图所示:

3 相关属性设置

Java Swing的很多属性设置用的方法,而NET用的属性.例如设置窗体标题,java swing用的是setTitle().另外窗体居中用的是setLocationRelativeTo(getOwner()). 获取文本框的值为getText()方法,如下代码所示:

1     public Login() {        
2         initComponents();
3         setTitle("登录");   
4         setDefaultCloseOperation(EXIT_ON_CLOSE);   
5         setVisible(true);     
6         setResizable(false);   
7         setLocationRelativeTo(getOwner()); //居中显示
8 
9     }

 1  private void btnLoginActionPerformed(java.awt.event.ActionEvent evt) {                                         
 2     // TODO add your handling code here:
 3     if(this.txtUserName.getText()!="" && this.txtPWD.getText().toString()!="")
 4     {
 5         Connection conn = DBConnection.getConnection();
 6         PreparedStatement ps = null;
 7         ResultSet rs = null;
 8         try {
 9             ps = conn.prepareStatement(
　　　　　　　　　"select * from users where UserName = ? and password = ?");
10             ps.setString(1,this.txtUserName.getText());// 
11             ps.setString(2, this.txtPWD.getText());
12             rs = ps.executeQuery();
13             while (rs.next()) {
14                 User user = new User();
15                 user.setId(rs.getInt("id"));
16                 user.setUsername(rs.getString("UserName"));
17                 user.setPassword(rs.getString("password"));
18                 
19                 System.out.println(user.toString());
20                 //跳转页面
21                 FrameMain frm=new FrameMain(user.getUsername());
22                 frm.setVisible(true);
23                 this.dispose();//关闭当前窗体
24                                 
25             }
26         } catch (SQLException e) {
27             e.printStackTrace();
28         } finally {
29             DBConnection.closeResultSet(rs);
30             DBConnection.closeStatement(ps);
31             DBConnection.closeConnection(conn);
32         }
33             
34      }
35  }                                       

 显示一个窗体是设置其setVisiable(true);关闭一个窗体用的dispose();在登录界面想着输完用户名和密码后,按enter键可以自动登录,在网上搜下,发现了一个变通的方法,就是监听密码框的keypressed事件,当然需要验证一下用户名和密码是否为空(此处未加验证!),如下代码所示:

1    private void txtPWDKeyPressed(java.awt.event.KeyEvent evt) {                                  
2         // TODO add your handling code here:
3         if(evt.getKeyCode()==KeyEvent.VK_ENTER)
4         {
5             //调用登录事件
6             btnLoginActionPerformed(null);
7             
8         }
9     }        

 4 主界面

登录成功后,单击左边的树叶节点,通过反射动态实例化窗体(实际上菜单应该从数据库加载)并显示,主界面如下:

 图表控件用的是JFreeChart控件,默认显示中文有乱码情况,需要设置显示中文处的字体进行解决.另外设置主界面显示最大化的代码为this.setExtendedState(this.getExtendedState()|JFrame.MAXMIZED_BOTH).为了让某个控件可以随着窗体大小变化而自动调整,需要设置其水平和垂直自动调整.

 1     public FrameMain(){
 2         initComponents();
 3          setLocationRelativeTo(getOwner()); //居中显示
 4          this.setExtendedState(this.getExtendedState()|JFrame.MAXIMIZED_BOTH );
　　　　　　　//最大化 window
 5          LoadTree();
 6       
 7     }
 8     public FrameMain(String uname){
 9         initComponents();
10          setLocationRelativeTo(getOwner()); //居中显示
11          this.setExtendedState(this.getExtendedState()|JFrame.MAXIMIZED_BOTH );
12          LoadTree();
13          this.lblUser.setText("欢迎 "+uname+ " 登录!");
14       
15     }

 主界面在初始化时,调用LoadTree方法来填充左边的菜单树,如下所示:

 1     private void LoadTree()
 2     {
 3         //自定义控件,支持关闭按钮
 4         jTabbedPane1.setCloseButtonEnabled(true);
 5  
 6         DefaultMutableTreeNode node1 = new DefaultMutableTreeNode("软件部");
 7         node1.add(new DefaultMutableTreeNode("产品部"));
 8         node1.add(new DefaultMutableTreeNode("测试部"));
 9         node1.add(new DefaultMutableTreeNode("设计部"));
10  
11         DefaultMutableTreeNode node2 = new DefaultMutableTreeNode("销售部");
12         node2.add(new DefaultMutableTreeNode("jack"));
13         node2.add(new DefaultMutableTreeNode("Lily"));
14         node2.add(new DefaultMutableTreeNode("Smith"));
15  
16         DefaultMutableTreeNode top = new DefaultMutableTreeNode("职员管理");
17            
18        
19         top.add(new DefaultMutableTreeNode("总经理"));
20         top.add(node1);
21         top.add(node2);
22        
23         //JTree tree=new JTree(top);       
24         DefaultTreeModel model = new DefaultTreeModel (top);     
25         this.jTree1.setModel(model);
26        //jTree1.getSelectionModel().setSelectionMode(TreeSelectionModel.SINGLE_TREE_SELECTION)      
27        //set jframe icon
28        try
29            
30        {
31        Image icon= ImageIO.read(this.getClass().getResource("/images/Icon.png"));
32        tabIcon = createImageIcon("/images/Icon.png", "tab icon");
33       
34        this.setIconImage(icon);
35        }
36        catch(IOException ex)
37        {
38            
39            System.out.println(ex);
40                    
41        }
42     
43     }

 在Tree的值变化事件中,通过class.forName()和 cls.newInstance()反射动态实例化窗体,代码如下:

 1     private void jTree1ValueChanged(javax.swing.event.TreeSelectionEvent evt) {                                    
 2         // TODO add your handling code here:
 3      
 4        DefaultMutableTreeNode node = (DefaultMutableTreeNode) 
　　　　　　　　jTree1.getLastSelectedPathComponent();
 5 
 6         if (node == null){
 7             //Nothing is selected.  
 8              return;
 9         }
10 
11         Object nodeInfo = node.getUserObject();
12         String item = (String) nodeInfo;
13 
14         if (node.isLeaf()) {
15             String item1 = (String) nodeInfo;
16             // this.setTitle(item1);
17             //File f = new File("client.jar");
18             //URLClassLoader cl = new URLClassLoader(new URL[]{f.toURI().toURL(), null});
19             //Class<?> clazz = cl.loadClass("epicurus.Client");
20             //Method main = clazz.getMethod("main", String[].class);
21             //main.invoke(null, new Object[]{new String[]{}});
22             try {
23                 Class cls = Class.forName("com.mkmis.forms.JIFrame1");
24                 javax.swing.JInternalFrame frm =
　　　　　　　　　　　　　　　　(javax.swing.JInternalFrame) cls.newInstance();
25                  frm.setVisible(true);
26 
27                 //jTabbedPane1.addTab(" "+item1+"  ",null,frm);
28                 jTabbedPane1.addTab(" "+item1+"  ",this.tabIcon,frm);
29 
30              }
31              catch (Throwable e) {
32                 System.err.println(e);
33              }
34         } else {
35             System.out.println("not leaf");
36         }
37     }       

 在javaswing中的路径也和net不同,下面定义了一个创建ImageIcon的方法:

 1     /** Returns an ImageIcon, or null if the path was invalid. */
 2     protected ImageIcon createImageIcon(String path,String description) {
 3         java.net.URL imgURL = getClass().getResource(path);
 4         if (imgURL != null) {
 5             return new ImageIcon(imgURL, description);
 6         } else {
 7             System.err.println("Couldn't find file: " + path);
 8             return null;
 9         }
10     }

 5 JDBC MYSQL代码

 1 package com.mkmis.db;
 2 
 3 import java.io.FileInputStream;
 4 import java.io.IOException;
 5 import java.sql.Connection;
 6 import java.sql.DriverManager;
 7 import java.sql.PreparedStatement;
 8 import java.sql.ResultSet;
 9 import java.sql.SQLException;
10 import java.sql.Statement;
11 import java.util.Properties;
12 
13 
14 public class DBConnection {
15 
16     public static Connection getConnection() {
17         Properties props = new Properties();
18         FileInputStream fis = null;
19         Connection con = null;
20         try {
21             fis = new FileInputStream("db.properties");
22             props.load(fis);
23             //
24             Class.forName(props.getProperty("DB_DRIVER_CLASS"));
25             // 
26             con = DriverManager.getConnection(props.getProperty("DB_URL"), props.getProperty("DB_USERNAME"), props.getProperty("DB_PASSWORD"));
27         } catch (IOException | SQLException | ClassNotFoundException e) {
28             e.printStackTrace();
29         }
30         return con;
31     }
32 
33     // �ر�ResultSet
34     public static void closeResultSet(ResultSet rs) {
35         if (rs != null) {
36             try {
37                 rs.close();
38                 rs = null;
39             } catch (SQLException e) {
40                 e.printStackTrace();
41             }
42         }
43     }
44 
45     //Statement
46     public static void closeStatement(Statement stm) {
47         if (stm != null) {
48             try {
49                 stm.close();
50                 stm = null;
51             } catch (SQLException e) {
52                 e.printStackTrace();
53             }
54         }
55     }
56 
57     //PreparedStatement
58     public static void closePreparedStatement(PreparedStatement pstm) {
59         if (pstm != null) {
60             try {
61                 pstm.close();
62                 pstm = null;
63             } catch (SQLException e) {
64                 e.printStackTrace();
65             }
66         }
67     }
68 
69     //Connection
70     public static void closeConnection(Connection con) {
71         if (con != null) {
72             try {
73                 con.close();
74                 con = null;
75             } catch (SQLException e) {
76                 e.printStackTrace();
77             }
78             con = null;
79         }
80     }
81 
82 }

View Code

 6 图表窗体代码

  1 /*
  2  * To change this license header, choose License Headers in Project Properties.
  3  * To change this template file, choose Tools | Templates
  4  * and open the template in the editor.
  5  */
  6 package com.mkmis.forms;
  7 
  8 import java.awt.Color;
  9 import java.awt.Dimension;
 10 import java.awt.Font;
 11 
 12 import org.jfree.chart.ChartFactory;
 13 import org.jfree.chart.ChartPanel;
 14 import org.jfree.chart.JFreeChart;
 15 import org.jfree.chart.StandardChartTheme;
 16 import org.jfree.chart.axis.CategoryAxis;
 17 import org.jfree.chart.axis.NumberAxis;
 18 import org.jfree.chart.block.BlockBorder;
 19 import org.jfree.chart.plot.CategoryPlot;
 20 import org.jfree.chart.renderer.category.BarRenderer;
 21 import org.jfree.chart.title.TextTitle;
 22 import org.jfree.data.category.CategoryDataset;
 23 import org.jfree.data.category.DefaultCategoryDataset;
 24 //import org.jfree.ui.ApplicationFrame;
 25 //import org.jfree.ui.RefineryUtilities;
 26 /**
 27  *
 28  * @author wangming
 29  */
 30 public class JIFrame1 extends javax.swing.JInternalFrame {
 31 
 32     /**
 33      * Creates new form JIFrame1
 34      */
 35     public JIFrame1() {
 36         initComponents();
 37         //hiding title bar of JInternalFrame       
 38         ((javax.swing.plaf.basic.BasicInternalFrameUI)this.getUI()).setNorthPane(null);
 39         this.setBackground(Color.white);
 40         
 41         CategoryDataset dataset = createDataset();
 42         JFreeChart chart = createChart(dataset);
 43         ChartPanel chartPanel = new ChartPanel(chart);
 44         chartPanel.setFillZoomRectangle(true);
 45         chartPanel.setMouseWheelEnabled(true);
 46         chartPanel.setPreferredSize(new Dimension(500, 270));
 47         setContentPane(chartPanel);
 48     }
 49 
 50     /**
 51      * This method is called from within the constructor to initialize the form.
 52      * WARNING: Do NOT modify this code. The content of this method is always
 53      * regenerated by the Form Editor.
 54      */
 55     @SuppressWarnings("unchecked")
 56     // <editor-fold defaultstate="collapsed" desc="Generated Code">                          
 57     private void initComponents() {
 58 
 59         setBorder(null);
 60         setClosable(true);
 61         setMaximizable(true);
 62         setResizable(true);
 63 
 64         javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
 65         getContentPane().setLayout(layout);
 66         layout.setHorizontalGroup(
 67             layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
 68             .addGap(0, 410, Short.MAX_VALUE)
 69         );
 70         layout.setVerticalGroup(
 71             layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
 72             .addGap(0, 285, Short.MAX_VALUE)
 73         );
 74 
 75         pack();
 76     }// </editor-fold>                        
 77 
 78         private static final long serialVersionUID = 1L;
 79 
 80     static {
 81         // set a theme using the new shadow generator feature available in
 82         // 1.0.14 - for backwards compatibility it is not enabled by default
 83         ChartFactory.setChartTheme(new StandardChartTheme("JFree/Shadow",
 84                 true));
 85     }
 86 
 87     /**
 88      * Creates a new demo instance.
 89      *
 90      * @param title  the frame title.
 91      */
 92     public JIFrame1(String title) {
 93         super(title);
 94         CategoryDataset dataset = createDataset();
 95         JFreeChart chart = createChart(dataset);
 96         ChartPanel chartPanel = new ChartPanel(chart);
 97         chartPanel.setFillZoomRectangle(true);
 98         chartPanel.setMouseWheelEnabled(true);
 99         chartPanel.setPreferredSize(new Dimension(500, 270));
100         setContentPane(chartPanel);
101     }
102 
103     /**
104      * Returns a sample dataset.
105      *
106      * @return The dataset.
107      */
108     private static CategoryDataset createDataset() {
109         DefaultCategoryDataset dataset = new DefaultCategoryDataset();
110         dataset.addValue(7445, "JFreeSVG", "Warm-up");
111         dataset.addValue(24448, "Batik", "Warm-up");
112         dataset.addValue(4297, "JFreeSVG", "Test");
113         dataset.addValue(21022, "Batik", "Test");
114         return dataset;
115     }
116 
117     /**
118      * Creates a sample chart.
119      *
120      * @param dataset  the dataset.
121      *
122      * @return The chart.
123      */
124     private static JFreeChart createChart(CategoryDataset dataset) {
125         //中文乱码,设置字体
126         Font font=new Font("微软雅黑",Font.BOLD,18);//测试是可以的
127       
128       
129        
130        
131         JFreeChart chart = ChartFactory.createBarChart("性能: JFreeSVG 对比 Batik", null /* x-axis label*/, 
132                 "毫秒" /* y-axis label */, dataset);
133         //中文乱码,设置字体
134         chart.getTitle().setFont(font);
135 
136         chart.addSubtitle(new TextTitle("在SVG中产生1000个图表"));
137         chart.setBackgroundPaint(Color.white);
138         CategoryPlot plot = (CategoryPlot) chart.getPlot();
139          NumberAxis rangeAxis = (NumberAxis) plot.getRangeAxis();
140          rangeAxis.setLabelFont(font);
141 
142          CategoryAxis domainAxis = plot.getDomainAxis();
143          domainAxis.setLabelFont(font);
144         // ******************************************************************
145         //  More than 150 demo applications are included with the JFreeChart
146         //  Developer Guide...for more information, see:
147         //
148         //  >   http://www.object-refinery.com/jfreechart/guide.html
149         //
150         // ******************************************************************
151 
152       
153         rangeAxis.setStandardTickUnits(NumberAxis.createIntegerTickUnits());
154         BarRenderer renderer = (BarRenderer) plot.getRenderer();
155         renderer.setDrawBarOutline(false);
156         chart.getLegend().setFrame(BlockBorder.NONE);
157         return chart;
158     }
159 
160     /**
161      * Starting point for the demonstration application.
162      *
163      * @param args  ignored.
164      */
165 //    public static void main(String[] args) {
166 //        BarChartDemo1 demo = new BarChartDemo1("JFreeChart: BarChartDemo1.java");
167 //        demo.pack();
168 //        RefineryUtilities.centerFrameOnScreen(demo);
169 //        demo.setVisible(true);
170 //    }
171 
172     // Variables declaration - do not modify                     
173     // End of variables declaration                   
174 }

View Code

 运行此app,一定要引入需要的库,mysql jdbc驱动和jfreechart库