//创建一个能在内存中图片的对象
int width = 100;
int heigth = 50;
BufferedImage bi = new
BufferedImage(width,heigth,BufferedImage.TYPE_INT_RGB);
//美化
Graphics gp = bi.getGraphics();//获取画笔对象
gp.setColor(Color.green);//设置画笔颜色
gp.fillRect(0,0,width,heigth);
//画边框
gp.setColor(Color.yellow);
gp.drawRect(0,0,width-1,heigth-1);
//写验证码
String str = "ABCDEFGHIGKLMNOPQRSTUVWXYZabcdefghigklmnopqrstuvwxyz123456789";
//生成随机角标
Random r = new Random();
gp.setColor(Color.black);
for (int i = 1; i <= 4; i++) {
//获取字符
int in = r.nextInt(str.length());
int he = r.nextInt(heigth);
char c = str.charAt(in);
gp.drawString(c+"",width/5*i,he);
}
//画干扰线
gp.setColor(Color.BLUE);
//随机生成15条干扰线
for (int i = 0; i < 15; i++) {
int x1 = r.nextInt(width);
int x2 = r.nextInt(width);
int y1 = r.nextInt(heigth);
int y2 = r.nextInt(heigth);
gp.drawLine(x1 ,y1,x2,y2);
}
//输出到页面
ImageIO.write(bi,"jpg",response.getOutputStream());
前端页面设置
<script>
//给超链接和图片链接添加单击事件
window.onload=function () {
//获取图片对象
var im = document.getElementById("checkCode");
//绑定单击事件
im.onclick = function () {
im.src="/res?"+new Date().getTime()
}
var ch = document.getElementById("change");
ch.onclick = function () {
im.src = "/res?"+new Date().getTime()
}
}
//重设图片的src
</script>
<body>
<img src="/res" id="checkCode">
<a href="" id="change">看不清？</a>
</body>
</html>
