创建随机验证码

<pre name="code" class="java">package image;


import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Font;
import java.awt.GradientPaint;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.security.cert.Certificate;
import java.util.Random;


import javax.imageio.ImageIO;


import org.hibernate.validator.constraints.Length;
import org.junit.Test;


public class VerrifyCode {
	private int w=70;
	private int h=35;
	private Random r = new Random();
	//设置字体
	private String[] fontNames= {"宋体","华文楷体","黑体","微软雅黑","楷体_GB2312"};
	//可选字母
	private String codes="23456789abcdefghijkmnopqrstuvwxyzABCDEFGHJKLMNPQRSTUVWXYZ";
	//背景色
	private Color bgColor = new Color(255,255,255);
	//验证码上的文字
	private String text;
	
	// 生成随机的颜色
	private Color randomColor(){
		int red =r.nextInt(150);
		int green =r.nextInt(150);
		int blue = r.nextInt(150);
		return new Color(red,green,blue);
	}
	
	//生成随机的字体
	private Font randomFont(){
		int index = r.nextInt(fontNames.length);
		String fontName = fontNames[index];// 生成随机的字体名称	
		int style = r.nextInt(4);//生成随机样式 0(无样式),1(粗体),2(斜体),3(粗+斜体)
		int size = r.nextInt(5)+24;// 生成随机字号  24~28
		return new Font(fontName,style,size);
	}
	
	//画干扰线
	private void drawLine(BufferedImage image){
		int num =3;//总共三条线
		Graphics2D g2 = (Graphics2D)image.getGraphics();
		for(int i=0;i<num;i++){//生成两个点的座标，四个值
			int x1 = r.nextInt(w);
			int y1 = r.nextInt(h);
			int x2 = r.nextInt(w);
			int y2 = r.nextInt(h);
			g2.setStroke(new BasicStroke(1.5F));
			g2.setColor(Color.BLUE);// 线是蓝色
			g2.drawLine(x1, y1, x2, y2);// 划线
		}
	}
	
	//随机生成一个字符
	private char randomChar(){
		int index = r.nextInt(codes.length());
		return codes.charAt(index);
	}
	//创建BufferedImage
	private BufferedImage createImage(){
		BufferedImage image = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
		Graphics2D g2 = (Graphics2D)image.getGraphics();
		g2.setColor(this.bgColor);
		g2.fillRect(0, 0, w, h);
		return image;
	}
	
	//调用这个方法获取验证码
	public BufferedImage getImage(){
		BufferedImage image = createImage();// 创建图片缓冲区
		Graphics2D g2 = (Graphics2D)image.getGraphics();//得到绘制环境
		StringBuilder sb = new StringBuilder();//用来装载生成的验证码文本
		//像图片中画4个字符
		for(int i=0;i<4;i++){//循环4次，每次生成一个字符
			String s = randomChar()+"";//随机生成一个字符
			sb.append(s);//把字符添加到sd中
			float x=i*1.0F*w/4;//设置当前座标的x轴
			g2.setFont(randomFont());//设置随机字体
			g2.setColor(randomColor());//设置随机颜色
			g2.drawString(s, x, h-5);//画图
		}
		this.text=sb.toString();// 把生成的字符串给了this.text
		drawLine(image);//添加干扰线
		return image;
	}
	
	// 返回验证码上的文字
	public String getText(){
		return text;
	}
	
	// 保存图片到指定的输出流
	public static void output (BufferedImage image,OutputStream out)
		throws IOException{
		ImageIO.write(image, "JPEG", out);
		
		
	}
	@Test
	//运行~
	public void fun() throws FileNotFoundException,IOException{
		VerrifyCode vc = new VerrifyCode();
		BufferedImage bi =vc.getImage();
		VerrifyCode.output(bi,new FileOutputStream("F:/xxx.jpg") );
		
		System.out.println(vc.getText());
	}
}