图形验证码的生成

import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Random;


import javax.imageio.ImageIO;


public class VerifyCode {
private int w =70;
private int h =35;
private Random r  = new Random();

private String[] fontNames = {"宋体", "华文楷体", "黑体", "微软雅黑", "楷体_GB2312"};

private String codes = "23456789abcdefghjkmnpqrstuvwxyzABCDEFGHJKMNPQRSTUVWXYZ";

private Color bgcolor = new Color(255,255,255);

private String text;

private BufferedImage creatImage () 
{
BufferedImage image = new BufferedImage(w,h,BufferedImage.TYPE_INT_RGB);
Graphics2D g = (Graphics2D) image.getGraphics();
g.setColor(this.bgcolor);
g.fillRect(0, 0, w, h);
return image;
}

private char getChar()
{
int index = r.nextInt(codes.length());
return codes.charAt(index);
}

private Color randomColor()
{
int red = r.nextInt(150);
int green = r.nextInt(150);
int blue = r.nextInt(150);
return new Color(red,green,blue);
}

private Font randomFont()
{
int index = r.nextInt(fontNames.length);
String fontName = fontNames[index];
int style = r.nextInt(4);
int size = r.nextInt(5)+24;
return new Font(fontName,style,size);
}
private void drawLine(BufferedImage image)
{
int num = 3;
Graphics2D g = (Graphics2D)image.getGraphics();
for(int i=0;i<num;i++)
{
int x1 = r.nextInt(w);
int y1 = r.nextInt(h);
int x2 = r.nextInt(w);
int y2 = r.nextInt(h);
g.setStroke(new BasicStroke(1.5F));
g.setColor(Color.blue);
g.drawLine(x1, y1, x2, y2);
 
}
}
public BufferedImage getImage()
{
BufferedImage image = creatImage();
Graphics2D g = (Graphics2D)image.getGraphics();
StringBuilder sb = new StringBuilder();
for(int i= 0;i < 4; i++)
{
String s = getChar() + "";
sb.append(s);
float x = i*1.0f*w/4;
g.setFont(randomFont());
g.setColor(randomColor());
g.drawString(s, x, h-5);
}
this.text = sb.toString();
drawLine(image);
return image;
}

public static void output(BufferedImage image , OutputStream out) throws IOException
{
ImageIO.write(image,"JPEG",out);
}

}