JAVA 生成验证码图片

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.util.LinkedList;
import java.util.Random;
import javax.imageio.ImageIO;
import javax.servlet.http.HttpServletResponse;
import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGImageEncoder;
// import java.awt.Graphics;

public class Test
{
public String sRand = "";

public Test()
{

}

public Color getRandColor(int fc, int bc)
{// 给定范围获得随机颜色
Random random = new Random();
if (fc > 255) fc = 255;
if (bc > 255) bc = 255;
int r = fc + random.nextInt(bc - fc);
int g = fc + random.nextInt(bc - fc);
int b = fc + random.nextInt(bc - fc);
return new Color(r, g, b);
}

/**
* 通过文件创建图像 格式为jpg类型
*/
public void creatImage(String fileName, String content)
{
// 在内存中创建图象
int width = 60, height = 20;
BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
// 获取图形上下文
Graphics2D g = image.createGraphics();
// Graphics g=image.getGraphics();
// 生成随机类
Random random = new Random();
// 设定背景色
g.setColor(getRandColor(200, 250));
g.fillRect(0, 0, width, height);
// 设定字体
g.setFont(new Font("Times New Roman", Font.PLAIN, 18));
g.setColor(Color.black);// 黑色文字
g.drawString(content, 10, 15);
g.dispose();
try
{
File f = new File(fileName);
if (!f.exists())
{
f.createNewFile();
}
else
{
Thread.sleep(200);
f.delete();
f.createNewFile();
}
ImageIO.write(image, "jpg", f);
}
catch (Exception e)
{
e.printStackTrace();
}
}

/**
* 创建图像 格式为jpg类型
*
* @param content -
* String 图片输出内容
* @return java.awt.image.BufferedImage
* @since 2005-7-19
*/
public BufferedImage getBufferedImage(String content)
{
int width = 60, height = 20;
return getBufferedImage(content, width, height);
}

/**
* 创建图像 格式为jpg类型
*
* @param content -
* String 图片输出内容
* @param width -
* int 图片宽度
* @param height -
* int 图片高度
* @return java.awt.image.BufferedImage
* @since 2005-7-19
*/
public BufferedImage getBufferedImage(String content, int width, int height)
{
// 在内存中创建图象
BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
// 获取图形上下文
Graphics2D g = image.createGraphics();
// Graphics g=image.getGraphics();
// 生成随机类
Random random = new Random();
// 设定背景色
g.setColor(getRandColor(200, 250));
g.fillRect(0, 0, width, height);
// 设定字体
g.setFont(new Font("Times New Roman", Font.PLAIN, 18));
g.setColor(Color.black);// 黑色文字
g.drawString(content, 10, 15);
g.dispose();
return image;
}

/**
* 将现有BufferedImage融合进Response
*
* @param response -
* javax.servlet.http.ServletResponse 将使用的response对象
* @param img -
* java.awt.image.BufferedImage
* @since 2005-7-19
*/
public void response(HttpServletResponse response, BufferedImage img)
{
try
{
response.setContentType("image/jpg;charset=GB2312");// 设定输出的类型
JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(response.getOutputStream());
encoder.encode(img);// 对图片进行输出编码
}
catch (Exception e)
{
e.printStackTrace();
}
}

/**
* 返回一个4位的验证码
*/
public String getContent() throws InterruptedException
{
String content = "";
for (int i = 0; i < 4; i++)
{
content += getChar();
Thread.sleep(new Random().nextInt(10) + 10);// 休眠以控制字符的重复问题
}
System.out.println("---------------"+content);
return content;
}

/**
* 获取随机字符
*/
public char getChar()
{
Random random = new Random();
char ch = '0';
LinkedList ls = new LinkedList();
for (int i = 0; i < 10; i++)
{// 0-9
ls.add(String.valueOf(48 + i));
}
for (int i = 0; i < 26; i++)
{// A-Z
ls.add(String.valueOf(65 + i));
}
for (int i = 0; i < 26; i++)
{// a-z
ls.add(String.valueOf(97 + i));
}
int index = random.nextInt(ls.size());
if (index > (ls.size() - 1))
{
index = ls.size() - 1;
}
ch = (char)Integer.parseInt(String.valueOf(ls.get(index)));
return ch;
}

/**
* 测试
*/
public static void main(String[] args) throws Exception
{
Test c = new Test();
c.creatImage("d://me4.jpg", c.getContent());
}
}