Java File Operations

Java File Operations
Open a file

First, instantiate JFileChoosers. You can use FileNameExtensionFilter to set the filter. The return value of the showOpenDialog method is of the int type. Therefore, define a value. Finally, if the value is equal to JFileChooser. APPROVE_OPTION can be used to operate the file. The file path is printed here.

private JFileChooser chooser;FileNameExtensionFilter filter = new FileNameExtensionFilter(Allowed File, txt,jar);chooser.setFileFilter(filter);int value = chooser.showOpenDialog(TestOpen.this);if (value == JFileChooser.APPROVE_OPTION) {    File file = chooser.getSelectedFile();    System.out.println(file.getAbsolutePath());}

What should I do if I want to open multiple files?

chooser.setFileSelectionMode(JFileChooser.FILES_AND_DIRECTORIES);chooser.setMultiSelectionEnabled(true);int value = chooser.showOpenDialog(TestOpen.this);if (value == JFileChooser.APPROVE_OPTION) {    File file[] = chooser.getSelectedFiles();    for (int i = 0; i < file.length; i++) {        System.out.println(file[i].getAbsolutePath());    }}

Save files

To save the file, remember to check for exceptions. An error occurs if you accidentally save the file. Actually, it's nothing more than calling the createNewFile method.

try {    JFileChooser chooser = new JFileChooser();    int value = chooser.showSaveDialog(TestSave.this);    if (value == JFileChooser.APPROVE_OPTION) {        File newfFile = chooser.getSelectedFile();        if (newfFile.exists() == false) {            newfFile.createNewFile();        }    }} catch (HeadlessException e1) {    e1.printStackTrace();} catch (IOException e1) {    e1.printStackTrace();}