java如何生成登入隨機驗證碼
阿新 • • 發佈:2020-01-07
本文例項為大家分享了java生成登入隨機驗證碼的具體程式碼,供大家參考,具體內容如下
驗證碼工具類: VerifyUtil.java
import java.awt.*; import java.awt.image.BufferedImage; import java.util.HashMap; import java.util.Map; import java.util.Random; public class VerifyUtil { // 驗證碼字符集 private static final char[] CHARS = { '0','1','2','3','4','5','6','7','8','9','a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z','A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z'}; // 字元數量 private static final int SIZE = 4; // 干擾線數量 private static final int LINES = 5; // 寬度 private static final int WIDTH = 80; // 高度 private static final int HEIGHT = 40; // 字型大小 private static final int FONT_SIZE = 30; /** * 生成隨機驗證碼及圖片 */ public static Map<String,Object> createImage() { StringBuffer sb = new StringBuffer(); // 1.建立空白圖片 BufferedImage image = new BufferedImage(WIDTH,HEIGHT,BufferedImage.TYPE_INT_RGB); // 2.獲取圖片畫筆 Graphics graphic = image.getGraphics(); // 3.設定畫筆顏色 graphic.setColor(Color.LIGHT_GRAY); // 4.繪製矩形背景 graphic.fillRect(0,WIDTH,HEIGHT); // 5.畫隨機字元 Random ran = new Random(); for (int i = 0; i < SIZE; i++) { // 取隨機字元索引 int n = ran.nextInt(CHARS.length); // 設定隨機顏色 graphic.setColor(getRandomColor()); // 設定字型大小 graphic.setFont(new Font(null,Font.BOLD + Font.ITALIC,FONT_SIZE)); // 畫字元 graphic.drawString(CHARS[n] + "",i * WIDTH / SIZE,HEIGHT * 2 / 3); // 記錄字元 sb.append(CHARS[n]); } // 6.畫干擾線 for (int i = 0; i < LINES; i++) { // 設定隨機顏色 graphic.setColor(getRandomColor()); // 隨機畫線 graphic.drawLine(ran.nextInt(WIDTH),ran.nextInt(HEIGHT),ran.nextInt(WIDTH),ran.nextInt(HEIGHT)); } // 7.返回驗證碼和圖片 Map<String,Object> map = new HashMap<>(); //驗證碼 map.put("code",sb.toString()); //圖片 map.put("image",image); return map; } /** * 隨機取色 */ public static Color getRandomColor() { Random ran = new Random(); return new Color(ran.nextInt(256),ran.nextInt(256),ran.nextInt(256)); } }
獲取驗證碼
@GetMapping("/verify-code") public void getCode(HttpServletResponse response) throws Exception{ Map<String,Object> map = VerifyUtil.createImage(); //將圖片輸出給瀏覽器 BufferedImage image = (BufferedImage) map.get("image"); response.setContentType("image/png"); OutputStream os = response.getOutputStream(); ImageIO.write(image,"png",os); }
頁面
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>獲取驗證碼</title> </head> <body onload="getVerify()"> <h1>點選圖片切換驗證碼</h1><img id="img-verify" src="" alt="更換驗證碼" height="36" onclick="getVerify()"> </body> <script> //獲取驗證碼 function getVerify(){ document.getElementById("img-verify").src="/verify-code?"+Math.random(); } </script> </html>
更多關於驗證碼的文章請點選檢視: 《java驗證碼》
以上就是本文的全部內容,希望對大家的學習有所幫助,也希望大家多多支援我們。