Java Programming Language Table of Contents
- Java POI Poorly Obfuscated Interface Project to Load a SpreadSheet with Data
- Java File Operations with Text Box – Load and Save Text you type in
- Java in Eclipse Integrated Development Environment IDE
- Java Software Internationalization
- Java Multilistener – Event Demo that shows how you can listen to one or to all
- Java Serial Port
- Java – Set the Size of a FrameView programmatically
- Populate an Excel xlsx xls spread sheet with Apache POI Library
End TOC
Zip Archive of Source code: TextBoxWithFileOps
Type and edit normally in the text box. Load a file if you wish first. Then save off to file. Includes the use of a filechooser and a menu.
In the code below
- Main calls the class FileOpGUI and sets it visible. This must invoke all the following steps
- FileOpGUI assumes the name and initializes all the constituent pieces.
- Code at the bottom declares all the parts and pieces
- Next code after the Class declaration instantiates parts / pieces using the NEW syntax
- Some properties of the bits and pieces are set like titles
- Menu code in automatically entered but the programmer has to fill in what they do. In this case simple file ops like SAVE, OPEN
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 | <br /> /*<br /> * To change this template, choose Tools | Templates<br /> * and open the template in the editor.<br /> */</p><p> /*<br /> * FileOpGUI.java<br /> *<br /> * Created on Jan 13, 2012, 2:08:15 PM<br /> */<br /> package FileOperations;<br /> import java.io.*;<br /> //import java.util.prefs.Preferences;</p><p> /**<br /> *<br /> * @author F. Sandlewould<br /> */<br /> public class FileOpGUI extends javax.swing.JFrame {</p><p> /** Creates new form FileOpGUI */<br /> public FileOpGUI() {<br /> initComponents();<br /> }</p><p> /** This method is called from within the constructor to<br /> * initialize the form.<br /> * WARNING: Do NOT modify this code. The content of this method is<br /> * always regenerated by the Form Editor.<br /> */<br /> @SuppressWarnings("unchecked")<br /> // <editor-fold defaultstate="collapsed" desc="Generated Code">//GEN-BEGIN:initComponents<br /> private void initComponents() {</p><p> fileChooser = new javax.swing.JFileChooser();<br /> jScrollPane1 = new javax.swing.JScrollPane();<br /> FileContentsTextArea = new javax.swing.JTextArea();<br /> jScrollPane2 = new javax.swing.JScrollPane();<br /> UserPromptTextArea = new javax.swing.JTextArea();<br /> AppendTestButton = new javax.swing.JButton();<br /> jMenuBar1 = new javax.swing.JMenuBar();<br /> FileOperations = new javax.swing.JMenu();<br /> mnuOpenFile = new javax.swing.JMenuItem();<br /> mnuSaveFile = new javax.swing.JMenuItem();<br /> mnuNewFile = new javax.swing.JMenuItem();</p><p> setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);<br /> setTitle("File Operations");<br /> setName("FileFrame"); // NOI18N</p><p> FileContentsTextArea.setColumns(20);<br /> FileContentsTextArea.setRows(5);<br /> jScrollPane1.setViewportView(FileContentsTextArea);</p><p> UserPromptTextArea.setColumns(20);<br /> UserPromptTextArea.setRows(5);<br /> UserPromptTextArea.setText("User prompt");<br /> jScrollPane2.setViewportView(UserPromptTextArea);</p><p> AppendTestButton.setText("Append");<br /> AppendTestButton.addActionListener(new java.awt.event.ActionListener() {<br /> public void actionPerformed(java.awt.event.ActionEvent evt) {<br /> AppendTestButtonActionPerformed(evt);<br /> }<br /> });</p><p> FileOperations.setText("File");</p><p> mnuOpenFile.setText("Open");<br /> mnuOpenFile.addActionListener(new java.awt.event.ActionListener() {<br /> public void actionPerformed(java.awt.event.ActionEvent evt) {<br /> mnuOpenFileActionPerformed(evt);<br /> }<br /> });<br /> FileOperations.add(mnuOpenFile);</p><p> mnuSaveFile.setText("Save");<br /> mnuSaveFile.addActionListener(new java.awt.event.ActionListener() {<br /> public void actionPerformed(java.awt.event.ActionEvent evt) {<br /> mnuSaveFileActionPerformed(evt);<br /> }<br /> });<br /> FileOperations.add(mnuSaveFile);</p><p> mnuNewFile.setText("New");<br /> mnuNewFile.addActionListener(new java.awt.event.ActionListener() {<br /> public void actionPerformed(java.awt.event.ActionEvent evt) {<br /> mnuNewFileActionPerformed(evt);<br /> }<br /> });<br /> FileOperations.add(mnuNewFile);</p><p> jMenuBar1.add(FileOperations);</p><p> setJMenuBar(jMenuBar1);</p><p> javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());<br /> getContentPane().setLayout(layout);<br /> layout.setHorizontalGroup(<br /> layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)<br /> .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()<br /> .addContainerGap()<br /> .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)<br /> .addComponent(jScrollPane1, javax.swing.GroupLayout.Alignment.LEADING, javax.swing.GroupLayout.DEFAULT_SIZE, 673, Short.MAX_VALUE)<br /> .addComponent(jScrollPane2, javax.swing.GroupLayout.DEFAULT_SIZE, 673, Short.MAX_VALUE)<br /> .addComponent(AppendTestButton, javax.swing.GroupLayout.Alignment.LEADING))<br /> .addContainerGap())<br /> );<br /> layout.setVerticalGroup(<br /> layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)<br /> .addGroup(layout.createSequentialGroup()<br /> .addContainerGap()<br /> .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 313, javax.swing.GroupLayout.PREFERRED_SIZE)<br /> .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)<br /> .addComponent(jScrollPane2, javax.swing.GroupLayout.PREFERRED_SIZE, 60, javax.swing.GroupLayout.PREFERRED_SIZE)<br /> .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)<br /> .addComponent(AppendTestButton)<br /> .addContainerGap(51, Short.MAX_VALUE))<br /> );</p><p> pack();<br /> }// </editor-fold>//GEN-END:initComponents</p><p> //routine needed to append a line & update file<br /> //append line to the textarea<br /> //use the SaveFile function</p><p> private void mnuOpenFileActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_mnuOpenFileActionPerformed</p><p> fileChooser.setDialogTitle("Open SASL List");<br /> fileChooser.setApproveButtonText("Open");</p><p> int returnVal = fileChooser.showOpenDialog(this);<br /> if (returnVal == fileChooser.APPROVE_OPTION) {<br /> File file = fileChooser.getSelectedFile();<br /> try {<br /> // What to do with the file, e.g. display it in a TextArea<br /> FileContentsTextArea.read( new FileReader( file.getAbsolutePath() ), null );<br /> UserPromptTextArea.setText( "Opening: " + "\n"+ "\r" + file.getAbsolutePath());<br /> } catch (IOException ex) {<br /> UserPromptTextArea.setText("Problem accessing file"+file.getAbsolutePath());<br /> }<br /> } else {<br /> UserPromptTextArea.setText("File access cancelled by user.");<br /> }<br /> }//GEN-LAST:event_mnuOpenFileActionPerformed</p><p> private void mnuSaveFileActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_mnuSaveFileActionPerformed<br /> Writer output = null;<br /> fileChooser.setDialogTitle("Save SASL List");<br /> fileChooser.setApproveButtonText("Save");<br /> int returnVal = fileChooser.showOpenDialog(this);<br /> if (returnVal == fileChooser.APPROVE_OPTION) {<br /> File file = fileChooser.getSelectedFile();<br /> try{<br /> WriteFile(file.getAbsolutePath(),FileContentsTextArea.getText());<br /> }<br /> catch(NullPointerException ex){}<br /> } else {<br /> UserPromptTextArea.setText("File write cancelled by user.");<br /> }<br /> }//GEN-LAST:event_mnuSaveFileActionPerformed</p><p> private void mnuNewFileActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_mnuNewFileActionPerformed<br /> //open up the file chooser > user navigates to preferred location<br /> //user enters name in file chooser text line<br /> //user clicks enter</p><p> Writer output = null;<br /> fileChooser.setDialogTitle("Create new SASL log file");<br /> fileChooser.setApproveButtonText("Save As");<br /> int returnVal = fileChooser.showOpenDialog(this);<br /> if (returnVal == fileChooser.APPROVE_OPTION) {<br /> File file = fileChooser.getSelectedFile();<br /> try{<br /> WriteFile(file.getAbsolutePath(),FileContentsTextArea.getText());<br /> }<br /> catch(NullPointerException ex){}<br /> } else {<br /> UserPromptTextArea.setText("File write cancelled by user.");<br /> }</p><p> }//GEN-LAST:event_mnuNewFileActionPerformed</p><p> private void AppendTestButtonActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_AppendTestButtonActionPerformed<br /> AppendEntry("another line woot!");<br /> AppendEntry("PathFileName= "); // + fileChooser.getSelectedFile().getAbsolutePath() ); <--this part causes another exception!! ( null pointer )</p><p> }//GEN-LAST:event_AppendTestButtonActionPerformed</p><p> public void AppendEntry(String Line){<br /> FileContentsTextArea.append( "\n" + Line );<br /> //textarea -> file save<br /> try{<br /> WriteFile(fileChooser.getSelectedFile().getAbsolutePath(),FileContentsTextArea.getText());<br /> }<br /> catch( NullPointerException ex)<br /> {<br /> UserPromptTextArea.setText("Problem writing file > File not saved");<br /> }<br /> };</p><p> public void WriteFile(String PathFileName, String FileContents) throws NullPointerException{<br /> Writer output = null;<br /> try {<br /> output = new BufferedWriter(new FileWriter(PathFileName));<br /> output.write(FileContents);<br /> output.close();<br /> FileContentsTextArea.read( new FileReader( PathFileName ), null );<br /> UserPromptTextArea.setText( "File saved: " + "\n"+ "\r" + PathFileName);<br /> }<br /> catch (IOException ex) {<br /> UserPromptTextArea.setText("Problem writing file"+ PathFileName);<br /> throw new NullPointerException("Cannot write file");<br /> }<br /> }</p><p> /**<br /> * @param args the command line arguments<br /> */<br /> public static void main(String args[]) {<br /> /* Set the Nimbus look and feel */<br /> //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) "><br /> /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.<br /> * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html<br /> */<br /> try {<br /> for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {<br /> if ("Nimbus".equals(info.getName())) {<br /> javax.swing.UIManager.setLookAndFeel(info.getClassName());<br /> break;<br /> }<br /> }<br /> } catch (ClassNotFoundException ex) {<br /> java.util.logging.Logger.getLogger(FileOpGUI.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);<br /> } catch (InstantiationException ex) {<br /> java.util.logging.Logger.getLogger(FileOpGUI.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);<br /> } catch (IllegalAccessException ex) {<br /> java.util.logging.Logger.getLogger(FileOpGUI.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);<br /> } catch (javax.swing.UnsupportedLookAndFeelException ex) {<br /> java.util.logging.Logger.getLogger(FileOpGUI.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);<br /> }<br /> //</editor-fold></p><p> /* Create and display the form */<br /> java.awt.EventQueue.invokeLater(new Runnable() {</p><p> public void run() {<br /> new FileOpGUI().setVisible(true);<br /> }<br /> });<br /> }<br /> // Variables declaration - do not modify//GEN-BEGIN:variables<br /> private javax.swing.JButton AppendTestButton;<br /> private javax.swing.JTextArea FileContentsTextArea;<br /> private javax.swing.JMenu FileOperations;<br /> private javax.swing.JTextArea UserPromptTextArea;<br /> private javax.swing.JFileChooser fileChooser;<br /> private javax.swing.JMenuBar jMenuBar1;<br /> private javax.swing.JScrollPane jScrollPane1;<br /> private javax.swing.JScrollPane jScrollPane2;<br /> private javax.swing.JMenuItem mnuNewFile;<br /> private javax.swing.JMenuItem mnuOpenFile;<br /> private javax.swing.JMenuItem mnuSaveFile;<br /> // End of variables declaration//GEN-END:variables<br /> }</p><p> |
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