Java Netbeans 绝对路径

Question

我创建了一个文本编辑器和一个保存按钮，我需要创建一个绝对查找器，以便如果用户不输入 .txt，程序将自动执行此操作，以便它始终保存为 txt 文件。请帮忙吗？

我的保存按钮的代码

private void btnSaveActionPerformed(java.awt.event.ActionEvent evt) {                                        
    JFileChooser chooseFile = new JFileChooser();
    int choosing = chooseFile.showSaveDialog(this);

    if ( choosing == JFileChooser.APPROVE_OPTION)
    {
        try {
            PrintWriter fileSave = new PrintWriter(chooseFile.getSelectedFile());
            //absolute path ends with 

            fileSave.printf(txtArea.getText());
            fileSave.close();
            txtStatus.setText("Saved");

        } catch (FileNotFoundException ex) {
            Logger.getLogger(TextEditor.class.getName()).log(Level.SEVERE, null, ex);
        }

    }
}       

Answer 1

   import org.apache.commons.io.FilenameUtils;

     File f= chooseFile.getSelectedFile();
    String filePath=f.getAbsolutePath();
    if(!filePath.endsWith("txt")){
    if(FilenameUtils.indexOfExtension(filePath)==-1){//user has other provided extension
        filePath+=".txt";
    }
    }