Java Web Verification Code

Java Web Verification Code
1. RandomCode

RandomCode is a tool class for generating verification codes. It supports both English and digital verification codes. The verification codes include uppercase and lowercase letters and arrays. English I, o, and numbers 0 and 1 are confusing, not included in the verification code generation. RandomCode supports outputting jpg, bmp, png, and GIF verification codes.

 

/*** The RandomCode verification code can be generated using static methods and instance methods. ** Static method: ** // generate a 4-digit random Verification code * String code = RandomCode. randomString (4); ** // input the verification code image to the response output stream * // jpg * OutputStream OS = response. getOutputStream (); * RandomCode. write (code, 120, 30, OS, jpg); ** instance method: ** // instantiate the verification code class * RandomCode rc = new RandomCode (4 ); ** // input the verification code image to the response output stream * // jpg * OutputStream OS = response. getOutputStream (); * rc. write (120, 30, OS, jpg); ** // obtain the verification code String * String code = rc. getCode (); **/public class RandomCode {/*** Random verification code character */private static String base = abcdefghijkmnpqrstuvwxyzABCDEFGHJKLMNPQRSTUVWXYZ23456789; /***** Random verification code length */private int length = 4;/***** verification code String */private String code; /*** 4-digit random Verification Code */public RandomCode () {this. code = RandomCode. randomString (this. length);} public RandomCode (int length) {if (length> 0) {this. length = length;} this. code = RandomCode. randomString (this. length);}/*** generate Verification Code image * @ param width Image width * @ param height image height * @ return */public BufferedImage toImage (int width, int height) {return RandomCode. toImage (this. code, width, height);}/*** output verification code image, the default image format is jpeg * @ param width * @ param height * @ param OS * @ throws IOException */public void write (int width, int height, OutputStream OS) throws IOException {RandomCode. write (code, width, height, OS, jpeg);}/*** output verification code image * @ param width * @ param height * @ param OS * @ param format, supports jpg/jpeg/bmp/gif/png * @ throws IOException */public void write (int width, int height, OutputStream OS, String format) throws IOException {RandomCode. write (code, width, height, OS, format);} public int getLength () {return length;} public String getCode () {return code ;} /*** static method ** to generate a Random String * @ param length String length * @ return random String */public static String randomString (int length) {Random = new random (); stringBuffer sb = new StringBuffer (); for (int I = 0; I <length; I ++) {sb. append (base. charAt (random. nextInt (base. length ();} return sb. toString ();} /* ** Static Method * output verification code image * @ param code verification code string * @ param width Image width * @ param height image height * @ param OS image output stream * @ param format Image format, jpg/jpeg/bmp/gif/png * @ throws IOException */public static void write (String code, int width, int height, OutputStream OS, String format) throws IOException {BufferedImage image = toImage (code, width, height); ImageIO. write (image, format, OS);}/*** Static Method * outputs the verification code image, default image format jpeg * @ param code verification code string * @ param width Image width * @ param height image height * @ param OS image output stream * @ throws IOException */public static void write (string code, int width, int height, OutputStream OS) throws IOException {write (code, width, height, OS, jpeg );} /*** convert a static method * string to a verification code image * @ param code verification code string * @ param width: The image width of the verification code, in pixels * @ param height: The Image height of the verification code, unit pixel * @ return */public static BufferedImage toImage (String code, int width, int height) {// fontSize int fontSize = (int) Math. ceil (height * 0.9); if (fontSize <20) {fontSize = 20;} // The Position of the font on the Y coordinate int positionY = (int) Math. ceil (height * 0.8); int lenCode = code. length (); // calculate the font width int fontWidth = width/(lenCode + 2); BufferedImage image = new BufferedImage (width, height, BufferedImage. TYPE_INT_BGR); Graphics g = image. getGraphics (); // random color of the image background g. setColor (randomColor (new Random (), 200,250); g. fillRect (0, 0, width, height); // set the font g. setFont (new Font (Times New Roman, Font. BOLD, fontSize); // draw lines in the picture to achieve the obfuscation effect drawLines (g, width, height); // draw the verification code drawString (g, code, fontWidth, positionY); g. dispose (); return image ;} /*** static method ** on the image, talk to the seat * @ param g * @ param code verification code string * @ param fontWidth font width * @ param positionY font Y coordinate */private static void drawString (Graphics g, string code, int fontWidth, int positionY) {int len = code. length (); Random random = new Random (); for (int I = 0; I <len; I ++) {g. setColor (randomColor (random); g. drawString (String. valueOf (code. charAt (I), (I + 1) * fontWidth, positionY);} private static Color randomColor (Random random) {int r = random. nextInt (255); int g = random. nextInt (255); int B = random. nextInt (255); return new Color (r, g, B);} private static Color randomColor (Random random, int fc, int bc) {if (fc> 255) {fc = 255;} if (bc> 255) {bc = 255;} int diff = bc-fc; int r = fc + random. nextInt (diff); int g = fc + random. nextInt (diff); int B = fc + random. nextInt (diff); return new Color (r, g, B );} /** static Method * draw a line that is crossly And crossly crossed * @ param g * @ param width Verification Code Image width * @ param height Verification Code Image height */private static void drawLines (Graphics g, int width, int height) {Random random = new Random (); // number of rows int count = (int) (Math. ceil (random. nextDouble () * 100) + 100; for (int I = 0; I <count; I ++) {int fc = 160 + (int) Math. ceil (random. nextDouble () * 40); int bc = 200 + (int) Math. ceil (random. nextDouble () * 55); g. setColor (randomColor (random, fc, bc); int x = random. nextInt (width); int y = random. nextInt (height); int xl = random. nextInt (width/5); int yl = random. nextInt (height/5); g. drawLine (x, y, x + xl, y + yl );}}}

2 Servlet return verification code

Request Path http: // <website path>/random/code/servlet

 

@ WebServlet (/random/code/servlet) public class RandomCodeServlet extends HttpServlet {private static final long serialVersionUID = 1L; protected void service (HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {// Verification Code image width, in pixels int width = 120; // Verification Code Image height, in pixels int height = 30; // Verification Code image format String format = png; // The length of the verification code is int len = 4; // set the image format response. setContentType (image/+ format); // disable the browser from caching the image response. setHeader (Pragma, no-cache); response. setHeader (Cache-Control, no-cache); response. setDateHeader (Expires, 0); String code = RandomCode. randomString (len); // output the image to the response output stream RandomCode. write (code, width, height, response. getOutputStream (), format );}}

3 Strust2 return verification code

 

Public class RandomCodeAction extends ActionSupport {private static final long serialVersionUID =-7515645222798283236L;/*** get Verification Code */public void generateCode () {HttpServletResponse response = ServletActionContext. getResponse (); // The image width of the verification code, in the unit of int width = 120; // The Image height of the verification code, in the unit of int height = 30; // The image format of the verification code is String format = png; // The length of the verification code is int len = 4; // set the image format response. setContentType (image/+ format); // disable the browser from caching the image response. setHeader (Pragma, no-cache); response. setHeader (Cache-Control, no-cache); response. setDateHeader (Expires, 0); String code = RandomCode. randomString (len); // output the image to the response output stream try {RandomCode. write (code, width, height, response. getOutputStream (), format);} catch (IOException e) {e. printStackTrace ();}}}

Struts2 verification code configuration

 

Request Path http: // <website path>/randomCode_generateCode.do

4 SpringMVC return verification code

Request Path http: // <website path>/random/code/generate. do

 

Package com. rhui. web. controller; import java. io. IOException; import javax. servlet. http. httpServletResponse; import org. springframework. stereotype. controller; import org. springframework. web. bind. annotation. requestMapping; import com. rhui. util. randomCode; @ Controller @ RequestMapping (/random/code) public class RandomCodeController {@ RequestMapping (/generate. do) public void generateCode (HttpServletResponse response) {// The image width of the verification code, in the unit of int width = 120; // The Image height of the verification code, in the unit of int height = 30; // Verification Code image format String format = png; // The Verification Code character length int len = 4; // set the image format response. setContentType (image/+ format); // disable the browser from caching the image response. setHeader (Pragma, no-cache); response. setHeader (Cache-Control, no-cache); response. setDateHeader (Expires, 0); String code = RandomCode. randomString (len); // output the image to the response output stream try {RandomCode. write (code, width, height, response. getOutputStream (), format);} catch (IOException e) {e. printStackTrace ();}}}