Java code Generation picture Verification Code implementation

Describes an example of using Java code to generate a random picture verification code

Can be directly configured as a servlet, called directly on the page

Java code randomly generated picture verification code

Package com.rchm.util.images;

Import Java.awt.Color;

Import Java.awt.Font;

Import Java.awt.Graphics2D;

Import Java.awt.image.BufferedImage;

Import Java.io.FileOutputStream;

Import java.io.IOException;

Import Java.io.OutputStream;

Import Java.util.Random;

Import Javax.imageio.ImageIO;

/**

* Verification Code generator

*/

public class Validatecode {

The width of the picture.

private int width = 160;

The height of the picture.

private int height = 40;

Number of verification code characters

private int codecount = 5;

Verification Code Interference line number

private int linecount = 150;

Verification Code

private static String code = NULL;

Verification Code Picture Buffer

Private BufferedImage Buffimg=null;

Private char[] Codesequence = {' A ', ' B ', ' C ', ' D ', ' E ', ' F ', ' G ', ' H ', ' I ', ' J ', ' K ', ' L ',

' M ', ' N ', ' P ', ' Q ', ' R ', ' S ', ' T ', ' U ', ' V ', ' W ', ' X ', ' Y ',

' Z ', ' 1 ', ' 2 ', ' 3 ', ' 4 ', ' 5 ', ' 6 ', ' 7 ', ' 8 ', ' 9 '};

Public Validatecode () {

This.createcode ();

}

/**

*

* @param width picture wide

* @param height Picture height

*/

Public validatecode (int width,int height) {

This.width=width;

This.height=height;

This.createcode ();

}

/**

*

* @param width picture wide

* @param height Picture height

* @param number of Codecount characters

* @param linecount number of interference lines

*/

Public validatecode (int width,int height,int codecount,int linecount) {

This.width=width;

This.height=height;

This.codecount=codecount;

This.linecount=linecount;

This.createcode ();

}

public void Createcode () {

int x = 0,fontheight=0,codey=0;

int red = 0, green = 0, blue = 0;

x = width/(codecount +2);//widths of each character

Fontheight = height of height-2;//font

Codey = height-4;

Image buffer

buffimg = new BufferedImage (width, height,bufferedimage.type_int_rgb);

Graphics2D g = buffimg.creategraphics ();

Generate random numbers

Random Random = new Random ();

To fill an image with white

G.setcolor (Color.White);

G.fillrect (0, 0, width, height);

Creating fonts

Imgfontbyte imgfont=new imgfontbyte ();

Font font =imgfont.getfont (fontheight);

G.setfont (font);

for (int i = 0; i

int xs = random.nextint (width);

int ys = random.nextint (height);

int XE = Xs+random.nextint (WIDTH/8);

int ye = Ys+random.nextint (HEIGHT/8);

Red = random.nextint (255);

Green = Random.nextint (255);

Blue = Random.nextint (255);

G.setcolor (New Color (red, green, blue));

G.drawline (XS, Ys, Xe, ye);

}

Randomcode record of randomly generated verification code

StringBuffer Randomcode = new StringBuffer ();

A code that randomly generates Codecount characters.

for (int i = 0; i

String Strrand = string.valueof (Codesequence[random.nextint (codesequence.length)));

Produces a random color value that gives the output a different color value for each character.

Red = random.nextint (255);

Green = Random.nextint (255);

Blue = Random.nextint (255);

G.setcolor (New Color (red, green, blue));

g.DrawString (Strrand, (i + 1) * x, Codey);

The resulting four random numbers are grouped together.

Randomcode.append (Strrand);

}

Saves a four-bit number of Authenticode to the session.

Code = randomcode.tostring ();

}

public void Write (String path) throws IOException {

OutputStream SOS = new FileOutputStream (path);

This.write (SOS);

}

public void Write (OutputStream sos) throws IOException {

Imageio.write (buffimg, "PNG", SOS);

Sos.close ();

}

Public BufferedImage getbuffimg () {

return buffimg;

}

public static String GetCode () {

return code;

}

}

Use this class in the servlet:

Package com.rchm.util.images;

Import java.io.IOException;

Import javax.servlet.ServletException;

Import Javax.servlet.http.HttpServlet;

Import Javax.servlet.http.HttpServletRequest;

Import Javax.servlet.http.HttpServletResponse;

Import javax.servlet.http.HttpSession;

public class Validatecodeservlet extends HttpServlet {

Private static final long serialversionuid = 1L;

protected void doget (HttpServletRequest request,httpservletresponse response) throws Servletexception, IOException {

Response.setcontenttype ("Image/jpeg");

Response.setheader ("Pragma", "No-cache");

Response.setheader ("Cache-control", "No-cache");

Response.setdateheader ("Expires", 0);

Validatecode Vcode = new Validatecode (100,30,4,100);

HttpSession session = Request.getsession ();

Session.removeattribute ("Validatecode");

Vcode.write (Response.getoutputstream ());

Session.setattribute ("Validatecode", Vcode.getcode ());

Vcode.write (Response.getoutputstream ());

}

}

To configure the servlet access path in Web.xml:

Validatecodeservlet

Class>com.rchm.util.images.validatecodeservletclass>

Validatecodeservlet