Java生成图形验证码工具类

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>

以上所述是小编给大家介绍的Java生成图形验证码工具类，希望对大家有所帮助，如果大家有任何疑问请给我留言，小编会及时回复大家的。在此也非常感谢大家对服务器之家网站的支持！