Java uses ImageIO, AWT to generate picture verification code

1. Generate Verification Code tool class

 Public classCheckcodetool {PrivateInteger width = 80; PrivateInteger height = 38;  PublicString Getcheckcode (baseform baseform) {/** Drawing*/            //Step1, create a Memory image object (artboard)BufferedImage image =Newbufferedimage (width, height, bufferedimage.type_int_rgb); //Step2, getting brushesGraphics g =Image.getgraphics (); //step3, coloring a pen//random R = new Random ();SecureRandom r =NewSecureRandom (); //G.setcolor (New Color (R.nextint (255), R.nextint (255), R.nextint (255))); //Step4, setting the background color for the artboardG.fillrect (0, 0, width, height); //Step5, draw a random stringString number =GetNumber (); G.setcolor (NewColor (0, 0, 0)); //Storage to Redis (for login verification)            if(BaseForm! =NULL&&Stringutils.isnotempty (Baseform.getsessionid ())) {String Redischeckcodeid= "Checkcodeid"; Try {                    if(Redisutil.getinstance (). Isexists (Redischeckcodeid)) {redisutil.getinstance (). Remove (Redische                    Ckcodeid); } redisutil.getinstance (). Setstringwithseconds (Redischeckcodeid,number,60);//1 minute prescription}Catch(Exception e) {System.out.println ("Getcheckcode:error:" +e.tostring ()); }            }            //New Font (font, style, size)G.setfont (NewFont (NULL, Font.Italic, 20)); g.DrawString (number,5, 25); //Step6, add some interference lines.             for(inti = 0; I < 8; i++) {G.setcolor (NewColor (R.nextint (255), R.nextint (255), R.nextint (255)));            G.drawline (R.nextint (width), r.nextint (height), r.nextint (width), r.nextint (height)); }            /** Compress picture and output to client (browser)*/Bytearrayoutputstream out=NewBytearrayoutputstream (); String base64string= ""; Try{imageio.write (image,"JPEG", out); Base64string=Base64utils.encode (Out.tobytearray ()); } Catch(Exception e) {e.printstacktrace (); } finally {                if(Out! =NULL) {                    Try{out.close (); } Catch(IOException e) {e.printstacktrace (); }                }            }                        returnbase64string; }        //generate a random number as a verification code        Privatestring GetNumber () {string number= ""; String Pool= "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"; SecureRandom R=NewSecureRandom ();  for(inti = 0; I < 4; i++) { number+=Pool.charat (R.nextint (Pool.length ())); }            returnNumber ; }}

2. Test Verification Class

 Public class checkcodetest {    publicstaticvoid  main (string[] args) {        //  TODO auto-generated method stub        new  checkcodetool ();         = Checkcodetool.getcheckcode (new  baseform ());        System.out.println (Checkcode);    }}

Output:

/9J/4AAQSKZJRGABAGAAAQABAAD/2WBDAAGGB ...

The base64string string is passed to the front end to display the picture verification code.

Java uses ImageIO, AWT to generate picture verification code