Java code Generation image Verification Code implementation

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

Java code randomly generated image 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;
Number of interference lines for verification code
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 width
* @param height Picture high
*/
Public validatecode (int width,int height) {
This.width=width;
This.height=height;
This.createcode ();
}

/**
*
* @param width picture width
* @param height Picture high
* @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);//width 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 ();
Fill the 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 < LineCount; 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 recording of randomly generated verification codes
StringBuffer Randomcode = new StringBuffer ();
Randomly generates a Codecount character verification code.
for (int i = 0; i < Codecount; i++) {
String Strrand = string.valueof (Codesequence[random.nextint (codesequence.length)]);
Produces a random color value so that the color values for each character of the output will be different.
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);
}
Save the four-digit verification code 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 a 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 ());
}

}

Configure the servlet access path in Web. xml:

<servlet>
<servlet-name>validateCodeServlet</servlet-name>
<servlet-class>com.rchm.util.images.ValidateCodeServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>validateCodeServlet</servlet-name>
<url-pattern>code.images</url-pattern>

Java code Generation image Verification Code implementation