JAVA之驗證碼生成器

package cn.lonsun.rbac.utils;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Random;
/**

• 驗證碼生成器
• @author xujh

**/
public class ValidateCode {
// 圖片的寬度。
private int width = 160;
// 圖片的高度。
private int height = 40;
// 驗證碼字符個數
private int codeCount = 4;
// 驗證碼干擾線數
private int lineCount = 15;
// 驗證碼
private String code = null;
// 驗證碼圖片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 圖片寬
* @param height 圖片高
/
public ValidateCode(int width,int height) {
this.width=width;
this.height=height;
this.createCode();
}
/*
*
* @param width 圖片寬
* @param height 圖片高
* @param codeCount 字符個數
* @param lineCount 干擾線條數
*/
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);//每個字符的寬度  
   fontHeight = height - 2;//字體的高度  
   codeY = height - 4;  
     
   // 圖像buffer  
   buffImg = new BufferedImage(width, height,BufferedImage.TYPE_INT_RGB);  
   Graphics2D g = buffImg.createGraphics();  
   // 生成隨機數  
   Random random = new Random();  
   // 將圖像填充爲白色  
   g.setColor(Color.WHITE);  
   g.fillRect(0, 0, width, height);  
   // 創建字體  
   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記錄隨機產生的驗證碼  
   StringBuffer randomCode = new StringBuffer();  
    // 隨機產生codeCount個字符的驗證碼。  
    for (int i = 0; i < codeCount; i++) {  
        String strRand = String.valueOf(codeSequence[random.nextInt(codeSequence.length)]);  
        // 產生隨機的顏色值，讓輸出的每個字符的顏色值都將不同。  
        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);  
        // 將產生的四個隨機數組合在一起。  
        randomCode.append(strRand);  
    }  
    // 將四位數字的驗證碼保存到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;  
}  

}
創建實體對象
HttpSession session = request.getSession();
ValidateCode vCode = new ValidateCode(108, 38, 4, 0);
vCode.getCode()；//得到驗證碼
session.setAttribute(InternalAccount.LOGIN_CODE, vCode.getCode());//存到session並返回給瀏覽器
vCode.write(response.getOutputStream());