Introduction détaillée de la classe d'outils de code de vérification graphique de génération Java

Cet article présente principalement la classe d'outils Java pour générer des codes de vérification graphiques. Les idées de cet article sont clairement présentées de manière très détaillée. Les amis dans le besoin peuvent se référer à

L'effet de la génération de codes de vérification

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Classe de génération de code de vérification ValidateCode.java

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 Méthode d'appel de servlet

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 
 */ 
}

Classe de test

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(); 
  } 
 } 
}

configuration web.xml

<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>

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