java图形验证码生成工具类

 生成验证码效果

 

 

 

 

ValidateCode.java 验证码生成类

package cn.dsna.util.images;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Random;

import javax.imageio.ImageIO;
/**
 * 验证码生成器
 * @author dsna
 *
 */
public class ValidateCode {
	// 图片的宽度。
	private int width = 160;
	// 图片的高度。
	private int height = 40;
	// 验证码字符个数
	private int codeCount = 5;
	// 验证码干扰线数
	private int lineCount = 150;
	// 验证码
	private String code = null;
	// 验证码图片Buffer
	private BufferedImage buffImg=null;

	private char[] codeSequence = { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J',
			'K', 'L', 'M', 'N',  'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W',
			'X', 'Y', 'Z',  '1', '2', '3', '4', '5', '6', '7', '8', '9' };

	public  ValidateCode() {
		this.createCode();
	}

	/**
	 * 
	 * @param width 图片宽
	 * @param height 图片高
	 */
	public  ValidateCode(int width,int height) {
		this.width=width;
		this.height=height;
		this.createCode();
	}
	/**
	 * 
	 * @param width 图片宽
	 * @param height 图片高
	 * @param codeCount 字符个数
	 * @param lineCount 干扰线条数
	 */
	public  ValidateCode(int width,int height,int codeCount,int lineCount) {
		this.width=width;
		this.height=height;
		this.codeCount=codeCount;
		this.lineCount=lineCount;
		this.createCode();
	}
	
	public void createCode() {
		int x = 0,fontHeight=0,codeY=0;
		int red = 0, green = 0, blue = 0;
		
		x = width / (codeCount +2);//每个字符的宽度
		fontHeight = height - 2;//字体的高度
		codeY = height - 4;
		
		// 图像buffer
		buffImg = new BufferedImage(width, height,BufferedImage.TYPE_INT_RGB);
		Graphics2D g = buffImg.createGraphics();
		// 生成随机数
		Random random = new Random();
		// 将图像填充为白色
		g.setColor(Color.WHITE);
		g.fillRect(0, 0, width, height);
		// 创建字体
		ImgFontByte imgFont=new ImgFontByte();
		Font font =imgFont.getFont(fontHeight);
		g.setFont(font);
		
		for (int i = 0; i < lineCount; i++) {
			int xs = random.nextInt(width);
			int ys = random.nextInt(height);
			int xe = xs+random.nextInt(width/8);
			int ye = ys+random.nextInt(height/8);
			red = random.nextInt(255);
			green = random.nextInt(255);
			blue = random.nextInt(255);
			g.setColor(new Color(red, green, blue));
			g.drawLine(xs, ys, xe, ye);
		}
		
		// randomCode记录随机产生的验证码
		StringBuffer randomCode = new StringBuffer();
		// 随机产生codeCount个字符的验证码。
		for (int i = 0; i < codeCount; i++) {
			String strRand = String.valueOf(codeSequence[random.nextInt(codeSequence.length)]);
			// 产生随机的颜色值，让输出的每个字符的颜色值都将不同。
			red = random.nextInt(255);
			green = random.nextInt(255);
			blue = random.nextInt(255);
			g.setColor(new Color(red, green, blue));
			g.drawString(strRand, (i + 1) * x, codeY);
			// 将产生的四个随机数组合在一起。
			randomCode.append(strRand);
		}
		// 将四位数字的验证码保存到Session中。
		code=randomCode.toString();		
	}
	
	public void write(String path) throws IOException {
		OutputStream sos = new FileOutputStream(path);
			this.write(sos);
	}
	
	public void write(OutputStream sos) throws IOException {
			ImageIO.write(buffImg, "png", sos);
			sos.close();
	}
	public BufferedImage getBuffImg() {
		return buffImg;
	}
	
	public String getCode() {
		return code;
	}
}

ImgFontByte.java

package cn.dsna.util.images;
import java.io.ByteArrayInputStream;
import java.awt.*;
/**
 * ttf字体文件
 * @author dsna
 *
 */
public class ImgFontByte {
	public Font getFont(int fontHeight){
		try {
			Font baseFont = Font.createFont(Font.TRUETYPE_FONT, new ByteArrayInputStream(hex2byte(getFontByteStr())));
			return baseFont.deriveFont(Font.PLAIN, fontHeight);
		} catch (Exception e) {
			return new Font("Arial",Font.PLAIN, fontHeight);
		}
	}
	
	private  byte[] hex2byte(String str) { 
		if (str == null)
			return null;
		str = str.trim();
		int len = str.length();
		if (len == 0 || len % 2 == 1)
			return null;

		byte[] b = new byte[len / 2];
		try {
			for (int i = 0; i < str.length(); i += 2) {
				b[i / 2] = (byte) Integer
						.decode("0x" + str.substring(i, i + 2)).intValue();
			}
			return b;
		} catch (Exception e) {
			return null;
		}
	} /**
  * ttf字体文件的十六进制字符串
  * @return
  */
 private String getFontByteStr(){ return null;
		return str;//字符串太长 在附件中找
}
}

 ValidateCodeServlet.java Servlet调用方法 

package cn.dsna.util.images;

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

public class ValidateCodeServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;

	@Override
	protected void doGet(HttpServletRequest reqeust,
			HttpServletResponse response) throws ServletException, IOException {
		// 设置响应的类型格式为图片格式
		response.setContentType("image/jpeg");
		//禁止图像缓存。
		response.setHeader("Pragma", "no-cache");
		response.setHeader("Cache-Control", "no-cache");
		response.setDateHeader("Expires", 0);
		
		HttpSession session = reqeust.getSession();
		
		ValidateCode vCode = new ValidateCode(120,40,5,100);
		session.setAttribute("code", vCode.getCode());
		vCode.write(response.getOutputStream());
	}
/**
 * web.xml 添加servlet
	<servlet>
		<servlet-name>validateCodeServlet</servlet-name>
		<servlet-class>cn.dsna.util.images.ValidateCodeServlet</servlet-class>
	</servlet>	
	<servlet-mapping>
		<servlet-name>validateCodeServlet</servlet-name>
		<url-pattern>*.images</url-pattern>
	</servlet-mapping>

在地址栏输入XXX/dsna.images 测试
 */

}

 测试类

ValidateCodeTest.java

package cn.dsna.util.images;

import java.io.IOException;
import java.util.Date;

public class ValidateCodeTest {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		ValidateCode vCode = new ValidateCode(120,40,5,100);
		try {
			String path="D:/t/"+new Date().getTime()+".png";
			System.out.println(vCode.getCode()+" >"+path);
			vCode.write(path);
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

}

web.xml 配置

	<servlet>
		<servlet-name>validateCodeServlet</servlet-name>
		<servlet-class>cn.dsna.util.images.ValidateCodeServlet</servlet-class>
	</servlet>	
	<servlet-mapping>
		<servlet-name>validateCodeServlet</servlet-name>
		<url-pattern>*.images</url-pattern>
	</servlet-mapping>