效果图
在JAVA项目中验证码肯定是不可缺少的，首先给展示的是最简单的直接写在JSP中的验证码，可以通过session验证,也可以通过这段直接改写在controller中。
code.jsp
- <%@ page language=“java” pageEncoding=“UTF-8”%>
- <%@ page contentType=“image/jpeg” import=“java.awt.*,java.awt.image.*,java.util.*,javax.imageio.*” %>
- <%!
- /**
- * 生成随机着色
- */
- public Color getColor(){
- Random random = new Random();
- int r = random.nextInt(256);//0-255
- int g = random.nextInt(256);
- int b = random.nextInt(256);
- return new Color(r,g,b);
- }
- //定义验证码的随机字符串
- String randomStr = “ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz1234567890”;
- /**
- * 生成随机字符
- */
- public String getStr(){
- StringBuffer sb = new StringBuffer();
- Random random = new Random();
- for(int i=0;i<6;i++){
- sb.append(randomStr.charAt(random.nextInt(randomStr.length())));//每次提取一个随机字符
- }
- return sb.toString();
- }
- %>
- <%
- //设置响应头部信息告诉浏览器不缓存图片
- response.setHeader(“pragma”, “mo-cache”);
- response.setHeader(“cache-control”, “no-cache”);
- response.setDateHeader(“expires”, 0);
- BufferedImage image = new BufferedImage(100,30,BufferedImage.TYPE_INT_RGB);
- Graphics g = image.getGraphics();
- g.setColor(new Color(200,200,200));
- g.fillRect(0,0,100,30);
- Random random = new Random();
- //绘制40条干扰线
- for (int i = 0; i < 40; i++) {
- int x = random.nextInt(100);
- int y = random.nextInt(30);
- int xl = random.nextInt(x+10);
- int yl = random.nextInt(y+10);
- g.setColor(getColor());
- g.drawLine(x, y, x + xl, y + yl);
- }
- g.setFont(new Font(“宋体”, Font.ROMAN_BASELINE,24));
- g.setColor(Color.BLACK);
- String randomCode = getStr();
- StringBuffer sb = new StringBuffer();
- for(int i=0;i<randomCode.length();i++){
- g.drawString(randomCode.charAt(i)+“”,random.nextInt(10),20+random.nextInt(8));//sb.append(randomCode.charAt(i));
- g.translate(15,0);
- }
- //将验证码放入Session中
- session.setAttribute(“RANDOMCODE”,randomCode);
- //通过流将验证码图片输出
- ImageIO.write(image,“jpeg”,response.getOutputStream());
- out.clear();
- out = pageContext.pushBody();
- %>
前端显示
- <img src=“code.jsp” width=“48” height=“15”>
下面还有个例子。
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