About bufferedreader/writer and filedialog

Package hxy.widget.com; import Java. AWT. *; import Java. AWT. event. *; import Java. io. *; import javax. swing. jframe; public class aboutdialog extends jframe implements actionlistener {/*****/Private Static final long serialversionuid = bytes; private filedialog filedialog_save, filedialog_load; private menubar; // menu bar private menu; // menu private menuitem itemopen, itemsave; // menu item private Textarea text; // text field private bufferedreader in; // read text from the character input stream, buffer each character, so as to achieve efficient reading of characters, arrays, and rows. Private filereader file_reader; // used to read the volume stream. To read the original byte stream, consider using fileinputstreamprivate bufferedwriter out; // write the text to the character output stream and buffer each character to provide efficient writing of a single character, array, and string. Private filewriter file_writer; // convenient class for writing character files public aboutdialog () {super ("Open/Save"); setsize (800,600); setvisible (true ); menubar = new menubar (); menu = new menu ("file"); itemopen = new menuitem ("Open File"); itemsave = new menuitem ("save file "); itemopen. addactionlistener (this); itemsave. addactionlistener (this); menu. add (itemopen); menu. add (itemsave); menubar. add (menu); setmenubar (menubar); filedialog_save = new filedialo G (this, "save file", filedialog. save); filedialog_load = new filedialog (this, "Open File", filedialog. load); filedialog_save.addwindowlistener (New windowadapter () {public void windowclosing (invalid wevent e) {filedialog_save.setvisible (false) ;}}); filedialog_load.addwindowlistener (New windowadapter () {public void windowclosing (invalid wevent e) {filedialog_load.setvisible (false) ;}}); addwindowlistener (New windowadapter () {Public void windowclosing (invalid wevent e) {system. Exit (0) ;}}); text = new textarea ("text field .. "); Add (text, borderlayout. center);} public void actionreceivmed (actionevent e) {If (E. getsource () = itemopen) {filedialog_load.setvisible (true); text. settext (null); // clear the text field string s; If (filedialog_load.getfile ()! = NULL) {try {file = new file (filedialog_load.getdirectory (), filedialog_load.getfile (); // obtain the opened file file_reader = new filereader (File ); in = new bufferedreader (file_reader); While (S = in. readline ())! = NULL) {// Readline () reads a text line text. append (S + '\ n'); // do not forget the line break} In. close (); // close the stream and release all associated resources. File_reader.close (); // close the stream and release all associated resources. Close () in filereader inherits from inputstreamreader} catch (ioexception E2) {}}} else if (E. getsource () = itemsave) {filedialog_save.setvisible (true); If (filedialog_save.getfile ()! = NULL) {system. out. print (filedialog_save.getfile (); try {file = new file (filedialog_save.getdirectory (), filedialog_save.getfile (); // obtain the file to be saved file_writer = new filewriter (File ); out = new bufferedwriter (file_writer);/** public void write (string S, * int off, * int Len) * throws ioexception * ----------------------- * s-the string to be written * Off-offset from the start to read the character * len-number of characters to be written **/out. write (text. gettext (), 0 ,( Text. gettext (). Length (); Out. Close (); // close the stream and release all associated resources. File_writer.close (); // close the stream and release all associated resources .} Catch (ioexception E2) {}}} public static void main (string ARGs []) {New aboutdialog ();}}