图片验证码

package cn.itcast.image;

import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

import javax.imageio.ImageIO;

import org.junit.Test;

public class Demo {
    @Test
    public void fun1(){
        /*
         * 1创建图片缓冲区
         * 2、设置宽高.
         * 3、得到这个图片的绘制环境（得到画笔）
         * 4、保存起来
         */
        BufferedImage bi=new BufferedImage(70, 35, BufferedImage.TYPE_INT_RGB);
        Graphics2D g=(Graphics2D) bi.getGraphics();//得到绘制环境
        g.setColor(Color.WHITE);//设置笔的颜色
        g.fillRect(0, 0, 70, 35);//填充矩形（左上角坐标，宽高） 这里就是使用上一步的绘制环境填充了矩形，也就是背景
        g.setColor(Color.RED);//设置笔的颜色
        g.drawString("Hello", 2, 35-2);//图片上写入字符串，其中2,2是表示xy轴的坐标
        
        try {
            ImageIO.write(bi, "JPEG", new FileOutputStream("D://xxx.jpg"));
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    @Test
    public void fun2() throws FileNotFoundException{
        VerifyCode vc=new VerifyCode();
        BufferedImage bi=vc.getImage();
        VerifyCode.output(bi, new FileOutputStream("D://xxx1.jpg"));
        
        System.out.println(vc.getText());
    }
}

package cn.itcast.image;

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="23456789abdcefghjkmnopqrstuvwxyzABCDEFGHJKMNPQRSTUVWXYZ";
    private Color bgColor=new Color(255,255,255);
    private String text;
    
    private Color randomColor(){
        int red=r.nextInt(150);
        int green=r.nextInt(150);
        int blue=r.nextInt(150);
        return new Color(red,green,blue);
    }
    
    public char randomChar(){
        return codes.charAt(r.nextInt(codes.length()));
    }
    
    private Font randomFont(){
        int index=r.nextInt(fontNames.length);
        String fontName=fontNames[index];
        int style=r.nextInt(4);//随机生成的样式：0 无样式 1粗体  2斜体 3（粗体且斜体）
        int size=r.nextInt(5)+24;//生成随机字号
        return new Font(fontName,style,size);
    }
    
    private void drawLine(BufferedImage image){
        int num=3;//一共画三条线
        Graphics2D g2=(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);
            g2.setStroke(new BasicStroke(1.5F));
            g2.setColor(Color.BLUE);
            g2.drawLine(x1, y1, x2, y2);
        }
    }
    
    public BufferedImage getImage(){
        BufferedImage image=createImage();
        Graphics2D g2=(Graphics2D)image.getGraphics();
        StringBuilder sb=new StringBuilder();
        for(int i=0;i<4;i++){
            String s=randomChar()+"";
            sb.append(s);
            float x=i*1.0F*w/4;
            g2.setFont(randomFont());
            g2.setColor(randomColor());
            g2.drawString(s,x,h-5);
        }
        this.setText(sb.toString());
        drawLine(image);
        return image;
    }
    
    private void setText(String text) {
        this.text=text;
    }

    public BufferedImage createImage(){
        BufferedImage bi=new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
        Graphics2D g2=(Graphics2D)bi.getGraphics();
        g2.setColor(bgColor);
        g2.fillRect(0, 0, w, h);
        return bi;
    }

    public String getText() {
        return text;
    }
    public static void output(BufferedImage image,OutputStream out){
        try {
            ImageIO.write(image, "JPEG", out);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}