java验证码

jsp页面====

<tr>
<td align="right"> </td>
<td>
<img class="verifyCode" onclick="changeCode()" src="getVerifyCode" style="height:35px;">
</td>
</tr>
<tr>
<td align="right"></td>
<td><input class="verifyCode" name="verifyCode" placeholder="请输入验证码"> </td>
</tr>

/*初始化验证码*/
$(function(){
var src = "<%=basePath%>code/getVerifyCode?"+new Date().getTime(); //加时间戳，防止浏览器利用缓存
$('.verifyCode').attr("src",src); //jQuery写法

})
/*点击刷新验证码*/
function changeCode(){
var src = "<%=basePath%>code/getVerifyCode?"+new Date().getTime(); //加时间戳，防止浏览器利用缓存
$('.verifyCode').attr("src",src); //jQuery写法

}

后台代码=============

package controller.user;

import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;

import javax.imageio.ImageIO;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

import utile.VerifyCodeUtils;

@Controller
@RequestMapping("/code")
public class VerifyCodeController {
/* 获取验证码图片*/
@RequestMapping("/getVerifyCode ")

public void getVerificationCode(HttpServletResponse response,HttpServletRequest request) {

try {
int width=200;
int height=69;
BufferedImage verifyImg=new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB);
//生成对应宽高的初始图片
String randomText = VerifyCodeUtils.drawRandomText(width,height,verifyImg);
System.out.println("验证码内容randomText===="+randomText);
//单独的一个类方法，出于代码复用考虑，进行了封装。
//功能是生成验证码字符并加上噪点，干扰线，返回值为验证码字符
request.getSession().setAttribute("verifyCode", randomText);
response.setContentType("image/png");//必须设置响应内容类型为图片，否则前台不识别
OutputStream os = response.getOutputStream(); //获取文件输出流
ImageIO.write(verifyImg,"png",os);//输出图片流
os.flush();
os.close();//关闭流
} catch (IOException e) {
e.printStackTrace();

}

}

}

package utile;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.util.Random;
/**
* 验证码
*/
public class VerifyCodeUtils{

public static String drawRandomText(int width,int height,BufferedImage verifyImg) {
Graphics2D graphics = (Graphics2D)verifyImg.getGraphics();
graphics.setColor(Color.WHITE);//设置画笔颜色-验证码背景色
graphics.fillRect(0, 0, width, height);//填充背景
graphics.setFont(new Font("微软雅黑", Font.BOLD, 40));
//数字和字母的组合
String baseNumLetter= "123456789abcdefghijklmnopqrstuvwxyzABCDEFGHJKLMNPQRSTUVWXYZ";
StringBuffer sBuffer = new StringBuffer();
int x = 10; //旋转原点的 x 坐标
String ch = "";
Random random = new Random();
for(int i = 0;i <4;i++){
graphics.setColor(getRandomColor());
//设置字体旋转角度
int degree = random.nextInt() % 30; //角度小于30度
int dot = random.nextInt(baseNumLetter.length());
ch = baseNumLetter.charAt(dot) + "";
sBuffer.append(ch);
//正向旋转
graphics.rotate(degree * Math.PI / 180, x, 45);
graphics.drawString(ch, x, 45);
//反向旋转
graphics.rotate(-degree * Math.PI / 180, x, 45);
x += 48;
}
//画干扰线
for (int i = 0; i <6; i++) {
// 设置随机颜色
graphics.setColor(getRandomColor());
// 随机画线
graphics.drawLine(random.nextInt(width), random.nextInt(height),
random.nextInt(width), random.nextInt(height));
}
//添加噪点
for(int i=0;i<30;i++){
int x1 = random.nextInt(width);
int y1 = random.nextInt(height);
graphics.setColor(getRandomColor());
graphics.fillRect(x1, y1, 2,2);
}
return sBuffer.toString();
}

/**
* 随机取色
*/
private static Color getRandomColor() {
Random ran = new Random();
Color color = new Color(ran.nextInt(256),
ran.nextInt(256), ran.nextInt(256));
return color;
}

}