how to use jfilechooser in java?
['Add required import statements: import javax.swing.JFileChooser; ... ', 'Create a new instance ofJFileChooser class: JFileChooser fileChooser = new JFileChooser();', 'Set current directory: ... ', 'Show up the dialog: ... ', 'Check if the user selects a file or not: ... ', 'Pick up the selected file: ... ', 'And the whole code snippet is as follows:']