JAVA生成隨機驗證碼
阿新 • • 發佈：2018-12-20
一、生成隨機圖片的java工具類
package com.xh.commen; import java.awt.*; import java.awt.image.BufferedImage; public class ImageUtil { private static String code=""; //記錄下隨機字母或數字 /** * 獲取生成圖片驗證碼 * */ public static BufferedImage getImage(){ //每次都要清空code code=""; //新建一個150*50的畫布 BufferedImage bufferedImage = new BufferedImage(150,50,BufferedImage.TYPE_INT_RGB); //獲得畫筆 Graphics graphics = bufferedImage.getGraphics(); //設定顏色 graphics.setColor(new Color(210,210,210)); //填充一個從（0，0）【左上角】開始的矩形，顏色為之前設定的 graphics.fillRect(0,0,150,50); //在畫布上寫字 drowString(graphics); //在畫布上畫隨機花點 drowDian(graphics); //在畫布上畫隨機劃線 drowLine(graphics); //在畫布上畫隨機弧線 drowArc(graphics); return bufferedImage; } //產生隨機的4個字母或數字 public static void drowString(Graphics graphics){ graphics.setFont(new Font("楷體",Font.ITALIC,24)); String dbString ="1234567890qwertyuioplkjhgfdsazxcvbnm" + "QWERTYUIOPLKJHGFDSAZXCVBNM"; for(int i = 1; i <= 4 ;i++){ char s = dbString.charAt((int)(Math.random()*dbString.length()-1)); String s1 = String.valueOf(s); code = code+s1; //生成隨機的顏色 graphics.setColor(new Color((int)(Math.random()*200),(int)(Math.random()*200),(int)(Math.random()*200))); //設定字出現的位置，字元會上下跳，數字根據自己的情況定 graphics.drawString(s1,24*i,(int)(Math.random()*9+30)); } } //獲取產生的隨機字串 public static String getCodeString(){ return code; } //繪製8個隨機點，隨機位置根據自己的畫布大小定 public static void drowDian(Graphics graphics){ for(int i = 1; i<=8;i++){ graphics.fillOval((int)(Math.random()*145), (int)(Math.random()*47),(int)(Math.random()*6), (int)(Math.random()*6)); } } //繪製4條隨機線，隨機位置根據自己的畫布大小定 public static void drowLine(Graphics graphics){ for(int i = 1;i<=4;i++){ graphics.drawLine((int)(Math.random()*145), (int)(Math.random()*48),(int)(Math.random()*145), (int)(Math.random()*48)); } } //繪製4條隨機弧線，隨機位置根據自己的畫布大小定 public static void drowArc(Graphics graphics){ for(int i = 1;i<=4;i++){ graphics.drawArc((int)(Math.random()*148), (int)(Math.random()*46),(int)(Math.random()*145), (int)(Math.random()*47), (int)(Math.random()*190),(int)(Math.random()*190)); } } }
二、呼叫ImageUtil工具類的Servlet程式碼
package com.xh.web;
import com.xh.commen.ImageUtil;
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;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.PrintWriter;
@WebServlet(name = "ImgServlet",urlPatterns = {"/img","/code"})
public class ImgServlet extends HttpServlet {
private String code;
//做驗證
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//獲取發來的驗證碼
String co = request.getParameter("code");
PrintWriter out = response.getWriter();
if(co.equalsIgnoreCase(code)){
out.print(1);
}else{
out.print(0);
}
}
//向前端傳送驗證碼圖片
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//獲取圖片
BufferedImage image = ImageUtil.getImage();
//獲取生成的隨機字串
code = ImageUtil.getCodeString();
//設定response的格式
response.setContentType("image/jpeg");
//向網頁輸出圖片
ImageIO.write(image,"jpg",response.getOutputStream());
}
}
三、前端HTML程式碼
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>驗證碼</title>
<script src="../lib/jquery-3.2.1.min.js"></script>
<script>
$(function () {
var i =0;
$("img").click(function () {
i++;
$(this).attr("src","../img?"+i);
})
$("input[name='code']").blur(function () {
var code = $(this).val();
$.ajax({
url:"../code",
type:"post",
data:{"code":code},
dataType:"text",
success:function (data) {
if(data == 0){
$("span").css("color","red");
$("span").html("驗證碼錯誤");
}else{
$("span").html("");
}
}
})
})
})
</script>
</head>
<body>
<label>驗證碼：</label><input type="text" name="code"><span></span>
<br>
<img src="../img"><i>看不清？點選圖片切換</i>
</body>
</html>四、效果圖
