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 icon28 try29 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�ResultSet34 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 //Statement46 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 //PreparedStatement58 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 //Connection70 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 }
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 JFreeChart146 // Developer Guide...for more information, see:147 //148 // > http://www.object-refinery.com/jfreechart/guide.html149 //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 }
运行此app,一定要引入需要的库,mysql jdbc驱动和jfreechart库
新闻热点
疑难解答
