java 生成图片验证

java 文件

package com.liuc.web.common;

import java.awt.Color;

import java.awt.Font;

import java.awt.Graphics2D;

import java.awt.image.BufferedImage;

import java.io.ByteArrayInputStream;

import java.io.ByteArrayOutputStream;

import java.io.InputStream;

import java.util.Random;

import javax.imageio.ImageIO;

import javax.imageio.stream.ImageOutputStream;

import com.opensymphony.xwork2.ActionContext;

/**

 * 图片验证码

 */

public class CheckCodeAction {

private int width = 70; //图片宽度

private int height = 18; //图片高度

private int count = 4; //码数

//验证码源

private char[] codes = {'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J',

'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W',

'X', 'Y', 'Z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9' };

private InputStream inputStream;

public String execute() throws Exception {

BufferedImage bi = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);

Graphics2D g = bi.createGraphics();

g.setColor(Color.WHITE);

g.fillRect(0, 0, width, height); //画背景

g.setColor(Color.BLACK);

g.drawRect(0, 0, width - 1, height - 1); //画边框

//设置画笔的颜色和字体

g.setFont(new Font("Fixedsys",Font.PLAIN, 14));

StringBuilder sb = new StringBuilder();  //用来保存产生的码值

Random random = new Random();

for(int i = 0; i < count; i++){

char c = codes[random.nextInt(codes.length)];

sb.append(c);

//产生随机颜色

g.setColor(new Color(random.nextInt(200), random.nextInt(200), random.nextInt(200)));

g.drawString(String.valueOf(c), i * (width/count)+2, height-3);

}

//随机数的干扰线 

for(int i = 0; i < 20; i++){

g.setColor(new Color(160 + random.nextInt(96), 

160 + random.nextInt(96), 160 + random.nextInt(96)));

int x = 2+random.nextInt(width);

int y = 2+random.nextInt(height);

int x1 = random.nextInt(6);

int y1 = random.nextInt(6);

g.drawLine(x, y, x+x1 > width - 3 ? width-3 : x+x1, y+y1 > height-3 ? height - 3 : y+y1);

}

//把产生的验证码值保存到当前会话中。

//ServletActionContext.getRequest().getSession().setAttribute("checkCode", sb.toString());

ActionContext.getContext().getSession().put("checkCode", sb.toString()); 

ByteArrayOutputStream output = new ByteArrayOutputStream();   

ImageOutputStream imageOut = ImageIO.createImageOutputStream(output);   

ImageIO.write(bi, "JPEG", imageOut); //把内存图片写到输出流

imageOut.close();   

this.inputStream = new ByteArrayInputStream(output.toByteArray());

return "success";

}

public InputStream getInputStream(){

return inputStream;

}

}

struts2 配置文件

<!-- 在这添加Action的配置 -->

<action name="checkcode" class="com.liuc.web.common.CheckCodeAction">   

    <result type="stream" name="success">

      <param name="contentType">image/jpeg</param>   

      <param name="inputName">inputStream</param>   

      </result>   

</action>

页面文件

<td><input style="border: #000000 1px solid" type="text" maxlength="8" size="11" value="" name="checkCode"/>&nbsp;

                <img alt="看不清楚，请点击换一张" src="${ctx}/checkcode.action" style="vertical-align:text-bottom; cursor: pointer;" onclick="this.src='${ctx}/checkcode.action?xx='+Math.random()"/></td>

loginAction 文件

String realCC = (String)ActionContext.getContext().getSession().get("checkCode");