jsp验证码代码:jsp动态图片验证码代码

很多新手对图片验证码不是很了解今天我们就来看看个例子吧首先,先写个动态图片生成Servlet类,如下:

package org.yuanliang;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.Random;

import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

public RandomCode extends HttpServlet {
private final long serialVersionUID = 1L;

private WIDTH = 65;//设置图片宽度

private HEIGHT = 22;//设置图片高度

public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
HttpSession session = request.getSession;
response.ContentType(\"image/jpeg\");
ServletOutputStream sos = response.getOutputStream;

response.Header(\"Pragma\", \"No-cache\");
response.Header(\"Cache-Control\", \"no-cache\");
response.DateHeader(\"Expires\", 0);

BufferedImage image = BufferedImage(WIDTH, HEIGHT,
BufferedImage.TYPE_INT_RGB);
Graphics g = image.getGraphics;

char rands = generateCheckCode;
drawBackground(g);
drawRands(g, rands);
g.dispose;

ByteArrayOutputStream bos = ByteArrayOutputStream;
ImageIO.write(image, \"JPEG\", bos);
buf = bos.toByteArray;
response.ContentLength(buf.length);
sos.write(buf);
bos.close;
sos.close;
session.Attribute(\"randomCode\", String(rands));
}

private void drawBackground(Graphics g) {
g.Color( Color(0xDCDCDC));
g.fillRect(0, 0, WIDTH, HEIGHT);
for ( i = 0; i < 120; i) {
x = () (Math.random * WIDTH);
y = () (Math.random * HEIGHT);
red = () (Math.random * 255);
green = () (Math.random * 255);
blue = () (Math.random * 255);
g.Color( Color(red, green, blue));
g.drawOval(x, y, 1, 0);[Page]
}
}

private void drawRands(Graphics g, char rands) {
// g.Color(Color.BLUE);
Random random = Random;
red = random.nextInt(110);
green = random.nextInt(50);
blue = random.nextInt(50);
g.Color( Color(red, green, blue));
g.Font( Font(null, Font.ITALIC | Font.BOLD, 18));
g.drawString(\"\" + rands[0], 1, 17);
g.drawString(\"\" + rands[1], 16, 15);
g.drawString(\"\" + rands[2], 31, 18);
g.drawString(\"\" + rands[3], 46, 16);
}

private char generateCheckCode {
String chars = \"0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ\";
char rands = char[4];
for ( i = 0; i < 4; i) {
rand = () (Math.random * 36);
rands[i] = chars.charAt(rand);
}
rands;
}

public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
this.doGet(request, response);
}
}

OK!!!保存为RandomCode.java吧,然后进行编译,生成RandomCode.文件,放到WEB-INF/es/org/yuanliang目录下;

然后在WEB-INF目录下建立web.xml,添加Servlet配置:


=m>
=m>
=m>
=m>
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=m>OK!!!开始运行你JSP页面吧,看有了没??

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