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本篇文章為大家展示了利用Java如何實現生成一個圖形驗證碼,內容簡明扼要并且容易理解,絕對能使你眼前一亮,通過這篇文章的詳細介紹希望你能有所收獲。
ValidateCode.java 驗證碼生成類
package cn.dsna.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; /** * 驗證碼生成器 * @author dsna * */ public class ValidateCode { // 圖片的寬度。 private int width = 160; // 圖片的高度。 private int height = 40; // 驗證碼字符個數 private int codeCount = 5; // 驗證碼干擾線數 private int lineCount = 150; // 驗證碼 private String code = null; // 驗證碼圖片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 圖片寬 * @param height 圖片高 */ public ValidateCode(int width,int height) { this.width=width; this.height=height; this.createCode(); } /** * * @param width 圖片寬 * @param height 圖片高 * @param codeCount 字符個數 * @param lineCount 干擾線條數 */ 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);//每個字符的寬度 fontHeight = height - 2;//字體的高度 codeY = height - 4; // 圖像buffer buffImg = new BufferedImage(width, height,BufferedImage.TYPE_INT_RGB); Graphics2D g = buffImg.createGraphics(); // 生成隨機數 Random random = new Random(); // 將圖像填充為白色 g.setColor(Color.WHITE); g.fillRect(0, 0, width, height); // 創建字體 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記錄隨機產生的驗證碼 StringBuffer randomCode = new StringBuffer(); // 隨機產生codeCount個字符的驗證碼。 for (int i = 0; i < codeCount; i++) { String strRand = String.valueOf(codeSequence[random.nextInt(codeSequence.length)]); // 產生隨機的顏色值,讓輸出的每個字符的顏色值都將不同。 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); // 將產生的四個隨機數組合在一起。 randomCode.append(strRand); } // 將四位數字的驗證碼保存到Session中。 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 String getCode() { return code; } }
ImgFontByte.java
package cn.dsna.util.images; import java.io.ByteArrayInputStream; import java.awt.*; /** * ttf字體文件 * @author dsna * */ public class ImgFontByte { public Font getFont(int fontHeight){ try { Font baseFont = Font.createFont(Font.TRUETYPE_FONT, new ByteArrayInputStream(hex2byte(getFontByteStr()))); return baseFont.deriveFont(Font.PLAIN, fontHeight); } catch (Exception e) { return new Font("Arial",Font.PLAIN, fontHeight); } } private byte[] hex2byte(String str) { if (str == null) return null; str = str.trim(); int len = str.length(); if (len == 0 || len % 2 == 1) return null; byte[] b = new byte[len / 2]; try { for (int i = 0; i < str.length(); i += 2) { b[i / 2] = (byte) Integer .decode("0x" + str.substring(i, i + 2)).intValue(); } return b; } catch (Exception e) { return null; } } /** * ttf字體文件的十六進制字符串 * @return */ private String getFontByteStr(){ return null; return str;//字符串太長 在附件中找 } }
ValidateCodeServlet.java Servlet調用方法
package cn.dsna.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; @Override protected void doGet(HttpServletRequest reqeust, HttpServletResponse response) throws ServletException, IOException { // 設置響應的類型格式為圖片格式 response.setContentType("image/jpeg"); //禁止圖像緩存。 response.setHeader("Pragma", "no-cache"); response.setHeader("Cache-Control", "no-cache"); response.setDateHeader("Expires", 0); HttpSession session = reqeust.getSession(); ValidateCode vCode = new ValidateCode(120,40,5,100); session.setAttribute("code", vCode.getCode()); vCode.write(response.getOutputStream()); } /** * web.xml 添加servlet <servlet> <servlet-name>validateCodeServlet</servlet-name> <servlet-class>cn.dsna.util.images.ValidateCodeServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>validateCodeServlet</servlet-name> <url-pattern>*.images</url-pattern> </servlet-mapping> 在地址欄輸入XXX/dsna.images 測試 */ }
測試類
ValidateCodeTest.java
package cn.dsna.util.images; import java.io.IOException; import java.util.Date; public class ValidateCodeTest { /** * @param args */ public static void main(String[] args) { ValidateCode vCode = new ValidateCode(120,40,5,100); try { String path="D:/t/"+new Date().getTime()+".png"; System.out.println(vCode.getCode()+" >"+path); vCode.write(path); } catch (IOException e) { e.printStackTrace(); } } }
web.xml 配置
<servlet> <servlet-name>validateCodeServlet</servlet-name> <servlet-class>cn.dsna.util.images.ValidateCodeServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>validateCodeServlet</servlet-name> <url-pattern>*.images</url-pattern> </servlet-mapping>
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