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This article introduces the knowledge of "how to use JAVA to write a text editor". Many people will encounter such a dilemma in the operation of actual cases, so let the editor lead you to learn how to deal with these situations. I hope you can read it carefully and be able to achieve something!

Let's analyze it again. There are several buttons in the last Menu. I don't know if you have found it. Two are still very simple. One is to build a new project, and the other is to exit. In the new project, we can instantiate the parent window again, but there is bug here. If you close any child window, the parent window will be closed. The other is to quit, just dispose () directly. Deal with it in the monitor:

You don't need to post too much context code here, just find the main window. Java and find the function.

@ Override public void actionPerformed (ActionEvent e) {if (e.getSource () = = item_about) {new about_Window ();} else if (e.getSource () = = item_word_format) {new about_Format ();} else if (e.getSource () = = item_new) {new test5 () / / Select New new A new window with bug, close any child window parent window will also close} else if (e.getSource () = = item_exit) {this.dispose ();}}

In the JAVA write text editor (1) we have analyzed that there is a packaged tool JFileChooser that can be called directly.

In fact, after digesting the introduction of this component in the hyperlink, there is no problem with file access. Next, we add a listener, and the corresponding method is added to the listener:

Of course, first declare JFileChooser in the class.

@ Override public void actionPerformed (ActionEvent e) {if (e.getSource () = = item_about) {new about_Window ();} else if (e.getSource () = = item_word_format) {new about_Format () } else if (e.getSource () = = item_new) {new test5 (); / / Select New new A new window with bug, closing any child window parent window will also close} else if (e.getSource () = = item_exit) {this.dispose () } else if (e.getSource () = = item_open) {openFile ();} else if (e.getSource () = = item_save) {saveFile ();}}

SaveFile method:

Private void saveFile () {File file = null; int result; fileChooser = new JFileChooser ("C:\\"); fileChooser.setApproveButtonToolTipText ("Save"); / / set the realistic text of the confirmation button fileChooser.setDialogTitle ("Save File"); / / set title result = fileChooser.showOpenDialog (rootPane) / / set the root View root layout of Dialog / /-if (result = = JFileChooser.APPROVE _ OPTION) {file = fileChooser.getSelectedFile () / / if the OK button is clicked Fill in the file path for file} / /-/ * FileOutputStream fileOutputStream = null / / File io class if (file! = null) {try {fileOutputStream = new FileOutputStream (file);} catch (FileNotFoundException e) {e.printStackTrace () } String content = edit_text_area.getText (); try {fileOutputStream.write (content.getBytes ()) } catch (IOException e) {e.printStackTrace () } finally {try {if (fileOutputStreamstreams null) {fileOutputStream.close () }} catch (IOException e) {e.printStackTrace () } * / /-there is a serious bug here, and there is no problem for writing characters to the file. However, there will be garbled codes when reading Chinese characters. Try {OutputStreamWriter write = new OutputStreamWriter (new FileOutputStream (file) "UTF-8") / / Transcoding a pair of characters BufferedWriter writer = new BufferedWriter (write); String content = edit_text_area.getText (); writer.write (content); writer.close ();} catch (IOException e) {e.printStackTrace () }}

OpenFile method:

/ * Click New and press item to open the JFileChooser dialog box * and process the file reading * / private void openFile () {File file = null; int result; fileChooser = new JFileChooser ("C:\"); fileChooser.setApproveButtonToolTipText ("OK") / / set the realistic text of the confirmation button fileChooser.setDialogTitle ("Open File"); / / set title result = fileChooser.showOpenDialog (rootPane) / / set the root View root layout of Dialog / /-if (result = = JFileChooser.APPROVE _ OPTION) {file = fileChooser.getSelectedFile () / / if the OK button is clicked Fill in the file path for file} / /-/ /- -the file is processed below. Load the content into the textarea of the parent form-/ * FileInputStream fileInputStream = null If (file! = null) {try {/ / notice the null pointer exception here, that is, fileInputStream = new FileInputStream (file) should be handled when the file is not found. / / load the data stream of file file into fileInputStream} catch (FileNotFoundException e) {/ / catch an exception and need to handle e.printStackTrace () / / instantiate the exception to e and print out the location and cause of the error in the console Console TipDialog tmpDialog = new TipDialog (this, "error file", true, "folder name error, please check again!") / / We can also do some processing for a scene here, where a warning dialog box pops up} / / read the file int readbyte Try {while ((readbyte = fileInputStream.read ())! =-1) {/ / read file edit_text_area.append (String.valueOf ((char) readbyte)) / / add}} catch (IOException e) {/ / handle exception e.printStackTrace () line by line in editarea } finally {try {if (fileInputStream! = null) {/ / a pair of fileInputStream recycled fileInputStream.close () }} catch (IOException e) {/ / throw exception e.printStackTrace () } * /-there is a serious bug here There will be garbled codes for reading Chinese characters. -if (file.isFile () & & file.exists ()) {BufferedReader reader = null Try {InputStreamReader inputStreamReader = new InputStreamReader (new FileInputStream (file), "UTF-8"); reader = new BufferedReader (inputStreamReader); String readLine = "" While ((readLine = reader.readLine ())! = null) {/ / a pair of BufferedReader data read row by row / / edit_text_area.append (readLine) If you write in this way, all sentences will appear on the same line, so add a newline character edit_text_area.append (readLine+'\ n') after each append. / / A pair of edit_text_area plus} reader.close () / / close reader} catch (IOException e) {e.printStackTrace (); / / TipDialog tmpDialog = new TipDialog (this, "error file", true, "folder name error, please check again!") }}}

In fact, the two methods here are very similar, you can get the path of the selected file through FileChooser, and then get the path through File, and then perform regular file read and write operations. Be sure to handle IO operation exceptions.

If you are paying attention, you can see that in fact, there are some operations in my IO that are commented out, and the commented-out part is in accordance with the read-write operation written using JFileChooser components, but after testing, it is found that there is no coding for Chinese characters, so it is garbled to read after saving it. So I used another way to write it.

This is the end of "how to use JAVA to write a text editor". Thank you for reading. If you want to know more about the industry, you can follow the website, the editor will output more high-quality practical articles for you!

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