简单验证码生成程序学习

  1 package com.javaweb.utils;
  2 
  3 import java.awt.BasicStroke;
  4 import java.awt.Color;
  5 import java.awt.Font;
  6 import java.awt.Graphics;
  7 import java.awt.Graphics2D;
  8 import java.awt.image.BufferedImage;
  9 import java.io.IOException;
 10 import java.io.OutputStream;
 11 import java.util.Random;
 12 
 13 import javax.imageio.ImageIO;
 14 /**
 15  * 一次性图片验证码程序
 16  * @author Administrator
 17  *
 18  */
 19 public class ValidateCode {
 20     private int width = 70;    // 图片宽度
 21     private int height = 35;    // 图片高度
 22     private Color bgcolor = new Color(240,240,240); // 背景颜色
 23     private Random random = new Random();    //用于生成伪随机数流
 24     private StringBuilder code = new StringBuilder(4);
 25     
 26     /**
 27      * 创建一张内存图片
 28      * @return
 29      */
 30     private BufferedImage createImage(){
 31         BufferedImage img = new BufferedImage(width, height,BufferedImage.TYPE_INT_RGB);
 32         // 设置画笔颜色
 33         img.getGraphics().setColor(bgcolor);
 34         // 填充一个和图片一样大小的矩形  相当于改变背景颜色
 35         img.getGraphics().fillRect(0, 0, width, height);
 36         return img;
 37     }
 38     //随机颜色
 39     private Color randomColor(){
 40         int r = random.nextInt(256);
 41         int g = random.nextInt(256);
 42         int b = random.nextInt(256);
 43         return new Color(r,g,b);
 44     }
 45     //随机大小
 46     private String[] fontName = {"宋体","华文楷体","黑体","华文新魏","华文隶书","微软雅黑","楷体_GB2312"};
 47     private int[] fontSize = {24,25,26,27,28};
 48     private Font randomFont(){
 49         int index = random.nextInt(fontName.length);// 获取fontName随机下标
 50         String name = fontName[index];
 51         int style = random.nextInt(4);// style范围 0,1,2,3
 52         index = random.nextInt(fontSize.length);// 获取fontSize随机下标
 53         int size = fontSize[index];        
 54         return new Font(name,style,size);
 55     }
 56     //随机字符
 57     private String strs = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
 58     private String randomChar(){
 59         int index = random.nextInt(strs.length());// 每个字符的索引
 60         return strs.charAt(index) + "";// 任何字符加上""都变字符串
 61     }
 62     // 设置干扰线
 63     private void setLines(BufferedImage img){
 64         Graphics2D g = (Graphics2D)img.getGraphics();
 65         g.setColor(Color.BLACK);// 设置干扰线颜色
 66         g.setStroke(new BasicStroke(1.5F));// 设置干扰线大小
 67         for(int i=0;i<5;i++){
 68             int x1 = random.nextInt(width);
 69             int y1 = random.nextInt(height);
 70             int x2 = random.nextInt(width);
 71             int y2 = random.nextInt(height);
 72             g.drawLine(x1, y1, x2, y2);
 73         }
 74     }
 75     /**
 76      * 得到图片
 77      * @return
 78      */
 79     public BufferedImage getImage(){
 80         /**
 81          * 1.得到图片
 82          * 2.随机字符，随机大小，随机颜色，随机字体
 83          * 3.返回
 84          */
 85         // 获取内存图片
 86         BufferedImage img = createImage();
 87         Graphics g = img.getGraphics();
 88         for(int i=0;i<4;i++){
 89             String ch = this.randomChar();
 90             code.append(ch);
 91             g.setColor(this.randomColor());
 92             g.setFont(this.randomFont());
 93             g.drawString(ch, width/4*i, height-5);
 94         }
 95         this.setLines(img);// 画干扰线
 96         return img;
 97     }
 98     /**
 99      * 该方法必须在getImage()之后
100      * 返回生成验证吗的字符串
101      * @return
102      */
103     public String getCode(){
104         return code.toString();
105     }
106     /**
107      * 保存图片
108      * @param img
109      * @param out
110      * @throws IOException
111      */
112     public void saveImage(BufferedImage img, OutputStream out) throws IOException{
113         ImageIO.write(img, "JPEG", out);
114     }
115 }

 1 public class ValidateCodeTest {
 2 
 3     @Test
 4     public void fun() throws FileNotFoundException, IOException{
 5         ValidateCode vc = new ValidateCode();
 6         BufferedImage img = vc.getImage();
 7         String code = vc.getCode();
 8         System.out.println(code);
 9         FileOutputStream fos = new FileOutputStream("E:/images/vcode.jpg");
10         vc.saveImage(img, fos);
11         fos.close();
12     }
13 }