用戶在注冊網(wǎng)站信息的時候基本上都要數(shù)據(jù)驗證碼驗證。那么圖片驗證碼功能該如何實現(xiàn)呢？
大概步驟是：
1.在內(nèi)存中創(chuàng)建緩存圖片
2.設(shè)置背景色
3.畫邊框
4.寫字母
5.繪制干擾信息
6.圖片輸出
廢話不多說，直接上代碼
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package com.lsgjzhuwei.servlet.response;import java.awt.Color;import java.awt.Font;import java.awt.Graphics;import java.awt.image.BufferedImage;import java.io.IOException;import java.util.Random;import javax.imageio.ImageIO;import javax.servlet.ServletException;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;/** * Servlet implementation class VerificationCode */@WebServlet(asyncSupported = true, urlPatterns = { "/VerificationCode" })public class VerificationCode extends HttpServlet { private static final long serialVersionUID = 1L; /** * @see HttpServlet#HttpServlet() */ public VerificationCode() { super(); // TODO Auto-generated constructor stub } /** * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) */ protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub int width = 120; int height = 30; //創(chuàng)建一張內(nèi)存中的緩存圖片 BufferedImage bufferedImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); ///背景色 //通過graphics繪制圖像 Graphics graphics = bufferedImage.getGraphics(); //設(shè)置顏色 graphics.setColor(Color.yellow); //填充 graphics.fillRect(0, 0, width, height); ///畫邊框 graphics.setColor(Color.blue); graphics.drawRect(0, 0, width-1, height-1); //寫字母 String content = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcedfghijklmnopqrstuvwxyz1234567890"; Random random = new Random(); //設(shè)置字體顏色 graphics.setColor(Color.red); //設(shè)置字體及大小 graphics.setFont(new Font("宋體", Font.BOLD, 20)); int x=20; int y=20; for(int i = 0; i < 4; i++) { int index = random.nextInt(content.length()); char letter = content.charAt(index); graphics.drawString(letter+" ", x, y); x = x+20; } //繪制干擾線 int x1; int x2; int y1; int y2; graphics.setColor(Color.LIGHT_GRAY); for(int i = 0;i <50;i++) { x1=random.nextInt(width); x2=random.nextInt(width); y1=random.nextInt(height); y2=random.nextInt(height); graphics.drawLine(x1, y1, x2, y2); } //將圖片輸出到瀏覽器 //將內(nèi)存的圖片通過瀏覽器輸出流輸出成jpg圖片 ImageIO.write(bufferedImage, "jpg", response.getOutputStream()); } /** * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) */ protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub }} |
以上這篇java web中圖片驗證碼功能的簡單實現(xiàn)方法就是小編分享給大家的全部內(nèi)容了，希望能給大家一個參考，也希望大家多多支持服務(wù)器之家。
