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