java後端生成驗證碼
阿新 • • 發佈:2018-11-26
package com.facebac.yun.web.servlet; import java.util.Random; import javax.imageio.ImageIO; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.awt.image.BufferedImage; import java.io.IOException; import java.awt.Graphics; import java.awt.Font; import java.awt.Color; /** * 驗證碼生成器類,可生成數字、大寫、小寫字母及三者混合型別的驗證碼。 支援自定義驗證碼字元數量; 支援自定義驗證碼圖片的大小; 支援自定義需排除的特殊字元; * 支援自定義干擾線的數量; 支援自定義驗證碼圖文顏色 */ @WebServlet("/code.jpg") public class ValidateCode { /** * 驗證碼型別為僅數字 0~9 */ public static final int TYPE_NUM_ONLY = 0; /** * 驗證碼型別為僅字母,即大寫、小寫字母混合 */ public static final int TYPE_LETTER_ONLY = 1; /** * 驗證碼型別為數字、大寫字母、小寫字母混合 */ public static final int TYPE_ALL_MIXED = 2; /** * 驗證碼型別為數字、大寫字母混合 */ public static final int TYPE_NUM_UPPER = 3; /** * 驗證碼型別為數字、小寫字母混合 */ public static final int TYPE_NUM_LOWER = 4; /** * 驗證碼型別為僅大寫字母 */ public static final int TYPE_UPPER_ONLY = 5; /** * 驗證碼型別為僅小寫字母 */ public static final int TYPE_LOWER_ONLY = 6; private ValidateCode() { } /** * 生成驗證碼字串 * * @param type * 驗證碼型別,參見本類的靜態屬性 * @param length * 驗證碼長度,大於0的整數 * @param exChars * 需排除的特殊字元(僅對數字、字母混合型驗證碼有效,無需排除則為null) * @return 驗證碼字串 */ public static String generateTextCode(int type, int length, String exChars) { if (length <= 0) return ""; StringBuffer code = new StringBuffer(); int i = 0; Random r = new Random(); switch (type) { // 僅數字 case TYPE_NUM_ONLY: while (i < length) { int t = r.nextInt(10); if (exChars == null || exChars.indexOf(t + "") < 0) {// 排除特殊字元 code.append(t); i++; } } break; // 僅字母(即大寫字母、小寫字母混合) case TYPE_LETTER_ONLY: while (i < length) { int t = r.nextInt(123); if ((t >= 97 || (t >= 65 && t <= 90)) && (exChars == null || exChars.indexOf((char) t) < 0)) { code.append((char) t); i++; } } break; // 數字、大寫字母、小寫字母混合 case TYPE_ALL_MIXED: while (i < length) { int t = r.nextInt(123); if ((t >= 97 || (t >= 65 && t <= 90) || (t >= 48 && t <= 57)) && (exChars == null || exChars.indexOf((char) t) < 0)) { code.append((char) t); i++; } } break; // 數字、大寫字母混合 case TYPE_NUM_UPPER: while (i < length) { int t = r.nextInt(91); if ((t >= 65 || (t >= 48 && t <= 57)) && (exChars == null || exChars.indexOf((char) t) < 0)) { code.append((char) t); i++; } } break; // 數字、小寫字母混合 case TYPE_NUM_LOWER: while (i < length) { int t = r.nextInt(123); if ((t >= 97 || (t >= 48 && t <= 57)) && (exChars == null || exChars.indexOf((char) t) < 0)) { code.append((char) t); i++; } } break; // 僅大寫字母 case TYPE_UPPER_ONLY: while (i < length) { int t = r.nextInt(91); if ((t >= 65) && (exChars == null || exChars.indexOf((char) t) < 0)) { code.append((char) t); i++; } } break; // 僅小寫字母 case TYPE_LOWER_ONLY: while (i < length) { int t = r.nextInt(123); if ((t >= 97) && (exChars == null || exChars.indexOf((char) t) < 0)) { code.append((char) t); i++; } } break; } return code.toString(); } /** * 已有驗證碼,生成驗證碼圖片 * * @param textCode * 文字驗證碼 * @param width * 圖片寬度 * @param height * 圖片高度 * @param interLine * 圖片中干擾線的條數 * @param randomLocation * 每個字元的高低位置是否隨機 * @param backColor * 圖片顏色,若為null,則採用隨機顏色 * @param foreColor * 字型顏色,若為null,則採用隨機顏色 * @param lineColor * 干擾線顏色,若為null,則採用隨機顏色 * @return 圖片快取物件 */ public static BufferedImage generateImageCode(String textCode, int width, int height, int interLine, boolean randomLocation, Color backColor, Color foreColor, Color lineColor) { BufferedImage bim = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); Graphics g = bim.getGraphics(); // 畫背景圖 g.setColor(backColor == null ? getRandomColor() : backColor); g.fillRect(0, 0, width, height); // 畫干擾線 Random r = new Random(); if (interLine > 0) { int x = 0, y = 0, x1 = width, y1 = 0; for (int i = 0; i < interLine; i++) { g.setColor(lineColor == null ? getRandomColor() : lineColor); y = r.nextInt(height); y1 = r.nextInt(height); g.drawLine(x, y, x1, y1); } } // 寫驗證碼 // g.setColor(getRandomColor()); // g.setColor(isSimpleColor?Color.BLACK:Color.WHITE); // 字型大小為圖片高度的80% int fsize = (int) (height * 0.8); int fx = height - fsize; int fy = fsize; g.setFont(new Font("Default", Font.PLAIN, fsize)); // 寫驗證碼字元 for (int i = 0; i < textCode.length(); i++) { fy = randomLocation ? (int) ((Math.random() * 0.3 + 0.6) * height) : fy;// 每個字元高低是否隨機 g.setColor(foreColor == null ? getRandomColor() : foreColor); g.drawString(textCode.charAt(i) + "", fx, fy); fx += fsize * 0.9; } g.dispose(); return bim; } /** * 生成圖片驗證碼 * * @param type * 驗證碼型別,參見本類的靜態屬性 * @param length * 驗證碼字元長度,大於0的整數 * @param exChars * 需排除的特殊字元 * @param width * 圖片寬度 * @param height * 圖片高度 * @param interLine * 圖片中干擾線的條數 * @param randomLocation * 每個字元的高低位置是否隨機 * @param backColor * 圖片顏色,若為null,則採用隨機顏色 * @param foreColor * 字型顏色,若為null,則採用隨機顏色 * @param lineColor * 干擾線顏色,若為null,則採用隨機顏色 * @return 圖片快取物件 */ public static BufferedImage generateImageCode(int type, int length, String exChars, int width, int height, int interLine, boolean randomLocation, Color backColor, Color foreColor, Color lineColor) { String textCode = generateTextCode(type, length, exChars); BufferedImage bim = generateImageCode(textCode, width, height, interLine, randomLocation, backColor, foreColor, lineColor); return bim; } /** * 產生隨機顏色 * * @return */ private static Color getRandomColor() { Random r = new Random(); Color c = new Color(r.nextInt(255), r.nextInt(255), r.nextInt(255)); return c; } public void validateCode(HttpServletRequest request, HttpServletResponse response) throws IOException { System.setProperty("java.awt.headless","true"); response.setHeader("Cache-Control", "no-cache"); String verifyCode = ValidateCode.generateTextCode(ValidateCode.TYPE_NUM_LOWER, 4, null); request.getSession().setAttribute("validateCode", verifyCode); response.setContentType("image/jpeg"); BufferedImage bim = ValidateCode.generateImageCode(verifyCode, 90, 30, 5, true, Color.WHITE, Color.BLUE, null); ImageIO.write(bim, "JPEG", response.getOutputStream()); } }
controller
public void validateCodeVue(HttpServletRequest request, HttpServletResponse response, String code_key) throws IOException { response.setHeader("Cache-Control", "no-cache"); System.setProperty("java.awt.headless", "true"); String verifyCode = ValidateCode.generateTextCode(ValidateCode.TYPE_NUM_LOWER, 4, null); //request.getSession().setAttribute("validateCode", verifyCode); LogUtils.info("獲取圖片驗證碼************code=" + verifyCode); String key = redisDBService.GET(code_key); if (key != null) { redisDBService.DEL(code_key); } redisDBService.SET(code_key, verifyCode, 60 * 5); response.setContentType("image/jpeg"); BufferedImage bim = ValidateCode.generateImageCode(verifyCode, 90, 30, 5, true, Color.WHITE, Color.BLUE, null); // 刪除以前的 request.getSession().removeAttribute("verifyCode"); request.getSession().setAttribute("verifyCode", verifyCode.toLowerCase()); ImageIO.write(bim, "JPG", response.getOutputStream()); }