Example of swing file selector for Java learning notes (four file read/write methods-and image read/write methods)

Package capture. selector; import Java. AWT. image; import Java. AWT. event. actionevent; import Java. AWT. event. actionlistener; import Java. AWT. image. bufferedimage; import Java. io. bufferedreader; import Java. io. bufferedwriter; import Java. io. file; import Java. io. fileinputstream; import Java. io. filenotfoundexception; import Java. io. fileoutputstream; import Java. io. filereader; import Java. io. filewriter; import Java. io. Ioexception; import Java. io. inputstreamreader; import Java. io. outputstreamwriter; import javax. swing. jbutton; import javax. swing. jfilechooser; import javax. swing. jframe; import javax. swing. jlabel; import javax. swing. joptionpane; import javax. swing. jscrollpane; import javax. swing. jtextarea; import javax. swing. swingutilities; import javax. swing. uimanager; import javax. swing. windowconstants; import Org. dyno. region L. swing. layouts. constraints; import Org. dyno. visual. swing. layouts. grouplayout; import Org. dyno. visual. swing. layouts. leading; import com.sun.image.codec.jpeg. export codec; import com.sun.image.codec.jpeg. export imageencoder; // vs4e -- Do not remove this line! /*** @ Author lushuaiyin * @ date 2011-10-18 */public class settest extends jframe {file targetfile; string message = ""; Private Static final long serialversionuid = 1l; private jtextarea jtextarea0; private jscrollpane jscrollpane0; private jbutton jbutton0; private jlabel jlabel1; private jbutton jbutton1; private jbutton jbutton2; Private Static final string preferred_look_and_feel = "javax. swing. plaf. meta L. metallookandfeel "; Public settest () {initcomponents ();} private void initcomponents () {setdefaclocloseoperation (windowconstants. dispose_on_close); setlayout (New grouplayout (); add (getjlabel1 (), new constraints (new leading (12, 12, 12), new leading (59, 22, 10, 10); add (getjbutton1 (), new constraints (new leading (52, 10, 10), new leading (142, 10, 10 ))); add (getjbutton0 (), new constraints (new leading (21 8, 10, 10), new leading (142, 12, 12); add (getjscrollpane0 (), new constraints (new leading (106,334, 10, 10 ), new leading (42, 51, 10, 10); add (getjbutton2 (), new constraints (new leading (329, 10, 10), new leading (142, 12, 12); setsize (501,240);} private jbutton getjbutton2 () {If (jbutton2 = NULL) {jbutton2 = new jbutton (); jbutton2.settext ("(image time) save as "); jbutton2.addactionlistener (New actionlistener () {Public void actionreceivmed (actionevent event) {try {jbutton2actionreceivmed (event);} catch (ioexception e) {// todo auto-generated catch blocke. printstacktrace () ;}});} return jbutton2;} private jbutton getjbutton1 () {If (jbutton1 = NULL) {jbutton1 = new jbutton (); jbutton1.settext ("select to read files"); jbutton1.addactionlistener (New actionlistener () {public void actionreceivmed (actionevent event) {JB Utton1actionactionreceivmed (event) ;}) ;}return jbutton1 ;}private jlabel getjlabel1 () {If (jlabel1 = NULL) {jlabel1 = new jlabel (); jlabel1.settext ("source file path");} return jlabel1;} private jbutton getjbutton0 () {If (jbutton0 = NULL) {jbutton0 = new jbutton (); jbutton0.settext ("Save as"); jbutton0.addactionlistener (New actionlistener () {public void actionreceivmed (actionevent event) {try {jbutton0actionpe Rformed (event);} catch (ioexception e) {// todo auto-generated catch blocke. printstacktrace () ;}});} return jbutton0;} private jscrollpane getjscrollpane0 () {If (jscrollpane0 = NULL) {jscrollpane0 = new jscrollpane (); response (getjtextarea0 ();} return jscrollpane0;} private jtextarea getjtextarea0 () {If (jtextarea0 = NULL) {jtextarea0 = new jtextarea (); Response ("jtextar Ea0 ");} return jtextarea0;} Private Static void installlnf () {try {string lnfclassname = preferred_look_and_feel; If (lnfclassname = NULL) lnfclassname = uimanager. getcrossplatformlookandfeelclassname (); uimanager. setlookandfeel (lnfclassname);} catch (exception e) {system. err. println ("cannot install" + preferred_look_and_feel + "on this platform:" + E. getmessage () ;}}/*** main entry of the class. * Note: This class is only created so that you can easily preview the result at runtime. * It is not expected to be managed by the designer. * You can modify it as you like. */public static void main (string [] ARGs) {installlnf (); swingutilities. invokelater (New runnable () {@ overridepublic void run () {settest frame = new settest (); frame. setdefaclocloseoperation (settest. exit_on_close); frame. settitle ("Se Ttest "); frame. getcontentpane (). setpreferredsize (frame. getsize (); frame. pack (); frame. setlocationrelativeto (null); frame. setvisible (true) ;}});} // read the file private void jbutton1actionactionreceivmed (actionevent event) {jfilechooser DLG = new jfilechooser ();/*** set the dialog box type, the method must be correct. Open the method control display page */DLG. setdialogtype (jfilechooser. open_dialog); // After setting the type and DLG. the Save dialog box is displayed only when the showopendialog (null) method is used together. // DLG. setdialogtype (J Filechooser. save_dialog); // After setting the type and DLG. the showdialog (null, "Haha") method is used together, and the first button is displayed as the second parameter "Haha ". // DLG. setdialogtype (jfilechooser. custom_dialog); // The parent component of the first parameter. The first parameter is the name of the first button (no longer open or saved) // DLG. showdialog (null, "Haha"); DLG. showopendialog (null); // DLG. showsavedialog (null); file = DLG. getselectedfile (); If (file = NULL) {This. message = "no file selected";} else {// What do you do after you get this file? system. out. println ("getabsolutepath --" + file. getabso Lutepath (); system. out. println ("getname --" + file. getname (); system. out. println ("isfile --" + file. isfile (); system. out. println ("isdirectory --" + file. isdirectory (); system. out. println ("getpath --" + file. getpath (); system. out. println ("getparent --" inclufile.getparent(%%%%this.tar GetFile = file; this. message = file. getpath (). tostring ();} jtextarea0.settext (this. message);} // save it as private void jbutton0actionactionreceivmed (Actionevent event) throws ioexception {fileinputstream FCM = NULL; inputstreamreader ISR = NULL; bufferedreader BR = NULL; fileoutputstream Fos = NULL; outputstreamwriter OSW = NULL; bufferedwriter BW = NULL; filereader Fr = NULL; filewriter fw = NULL; If (targetfile = NULL) {system. out. println ("the source file is empty. Select the file to save first! "); Joptionpane. showmessagedialog (null," the source file is empty. Select the file to save first! ");} Else {jfilechooser DLG = new jfilechooser (); DLG. setdialogtype (jfilechooser. save_dialog); DLG. showsavedialog (null); file getnewfile = DLG. getselectedfile (); string getnewpath = getnewfile. getpath (); string getnewname = getnewfile. getpath (); string getnewparent = getnewfile. getparent (); system. out. println ("getnewpath:" + getnewpath); system. out. println ("getnewname:" + getnewname); system. out. println ("getnewparent:: "+ Getnewparent); // write a new file. Try {// read the source file. The value is new fileinputstream(this.tar GetFile); ISR = new inputstreamreader (AIS); BR = new bufferedreader (ISR ); fr = new filereader(this.tar GetFile); // write the new file newfile = new file (getnewpath); If (! Newfile. exists () {newfile. createnewfile ();} Fos = new fileoutputstream (newfile); OSW = new outputstreamwriter (FOS); BW = new bufferedwriter (OSW); fw = new filewriter (newfile ); // The method for reading and writing files in Step 4 is provided below. All methods have passed the test. // Use bufferedreader and bufferedwriter to complete the experiment successfully. Note that a line break is added after reading a row! // String Ss = NULL; // while (Ss = Br. Readline ())! = NULL) {// BW. write (SS + "\ n"); // BW. flush (); // inputstreamreader and outputstreamwriter are used for the experiment. // char [] Buf = new char [2048]; // int num = 0; // while (num = ISR. read (BUF ))! = (-1) // {// whether to read the file // OSW. write (BUF, 0, num); // write the file data into the network buffer // OSW. flush (); // refresh the buffer to write data to the client //} // use filereader and filewriter for operation. The test is successful. // char [] cbuf = new char [1024]; // int nn = 0; // while (nn = Fr. read (cbuf ))! =-1) {// BW. write (cbuf, 0, NN); // BW. flush (); // use fileinputstream and fileoutputstream. The test is successful. byte [] B = new byte [512]; int N; while (n = FCM. read (B ))! =-1) {FOS. Write (n) ;}} catch (filenotfoundexception e) {e. printstacktrace () ;} finally {If (BW! = NULL) {BW. Close () ;}if (OSW! = NULL) {OSW. Close ();} If (FOS! = NULL) {FOS. Close () ;}if (BR! = NULL) {Br. Close () ;}if (ISR! = NULL) {ISR. Close () ;}if (fr! = NULL) {Fr. Close () ;}if (FW! = NULL) {FW. Close () ;}} joptionpane. showmessagedialog (null, "saved successfully! ") ;}} // Save the image as private void jbutton2actionreceivmed (actionevent event) throws ioexception {fileinputstream fis2 = NULL; inputstreamreader isr2 = NULL; bufferedreader Br2 = NULL; fileoutputstream fos2 = NULL; outputstreamwriter osw2 = NULL; bufferedwriter bw2 = NULL; filereader FR2 = NULL; filewriter fw2 = NULL; jfilechooser DLG = new jfilechooser (); DLG. setdialogtype (jfilechooser. save_dialog); DLG. showsavedialog (null ); File getnewfile = DLG. getselectedfile (); string getnewpath = getnewfile. getpath (); string getnewname = getnewfile. getpath (); string getnewparent = getnewfile. getparent (); system. out. println ("getnewpath:" + getnewpath); system. out. println ("getnewname:" + getnewname); system. out. println ("getnewparent:" + getnewparent); // write a new file try {// read the source file fis2 = new fileinputstream(this.tar GetFile); isr2 = new inputstreamreader (fis2); B R2 = new bufferedreader (isr2); image src = javax.imageio.imageio.read(this.tar GetFile); // construct the image object int Wideth = SRC. getwidth (null); // obtain the source image width, int Height = SRC. getheight (null); // get the source image length FR2 = new filereader(this.tar GetFile); // write the new file newfile = new file (getnewpath); If (! Newfile. exists () {newfile. createnewfile ();} fos2 = new fileoutputstream (newfile); osw2 = new outputstreamwriter (fos2); bw2 = new bufferedwriter (osw2); fw2 = new filewriter (newfile ); // graphics operation. The test is successful. bufferedimage tag = new bufferedimage (Wideth, height, bufferedimage. type_int_rgb); tag. getgraphics (). drawimage (SRC, Wideth, height, null); fos2 = new fileoutputstream (getnewpath); // output to the file stream using imageencoder encod ER = inclucodec. createjpegencoder (fos2); encoder. encode (TAG); // JPEG encoding} catch (filenotfoundexception e) {e. printstacktrace ();} finally {If (bw2! = NULL) {bw2.close ();} If (osw2! = NULL) {osw2.close ();} If (fos2! = NULL) {fos2.close ();} If (Br2! = NULL) {br2.close ();} If (isr2! = NULL) {isr2.close ();} If (FR2! = NULL) {fr2.close ();} If (fw2! = NULL) {fw2.close () ;}} joptionpane. showmessagedialog (null, "saved successfully! ");}}