图形验证码

有事我们登录需要使用到图形验证码，这里记录方便以后查询使用。

package testVerifyCode;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.Random;
import java.util.concurrent.ThreadLocalRandom;
import javax.imageio.ImageIO;
import javax.imageio.stream.FileImageOutputStream;
public class verifyCode_Demo {
    private static final String[][] existCode = new String[10][1];
    static {
        existCode[0][0] = "4-1=";existCode[1][0] = "9-0=";existCode[2][0] = "6+1=";
        existCode[3][0] = "9-8=";existCode[4][0] = "7-3=";existCode[5][0] = "2+6=";
        existCode[6][0] = "9x7=";existCode[7][0] = "3+4=";existCode[8][0] = "8x2=";
        existCode[9][0] = "8+4=";
    }
    public static void main(String[] args) throws IOException {
        String randomCode = generateVerifyCode();
        BufferedImage img = generteVerifyCodeImage(randomCode);
        byte[] data = bufferedImage2ByteArray(img);
        byte2image(data,"D:sd.png");
    }
    public static void byte2image(byte[] data, String path) throws FileNotFoundException, IOException {
        if (data.length < 3 || path.equals(""))
            return;
        FileImageOutputStream imageOutput = new FileImageOutputStream(new File(path));// 打开输入流
        imageOutput.write(data, 0, data.length);// 将byte写入硬盘
        imageOutput.close();
        System.out.println("Make Picture success,Please find image in " + path);
    }
    private static String generateVerifyCode() {
        String code = null;
        int index = ThreadLocalRandom.current().nextInt(10);
        code = existCode[index][0];
        return code;
    }
    private static BufferedImage generteVerifyCodeImage(String code) {
        Random random = new Random();
        // 在内存中创建一副图片
        int width = 100;
        int height = 40;
        BufferedImage img = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
        // 在图片上画一个矩形当背景
        Graphics g = img.getGraphics();
        g.setColor(new Color(randowNum(random, 110, 250),
         randowNum(random, 110, 250), randowNum(random, 110, 250)));
        g.fillRect(0, 0, width, height);
        for (int i = 0; i < code.length(); i++) {
            g.setColor(new Color(randowNum(random, 50, 180), 
            randowNum(random, 50, 180), randowNum(random, 50, 180)));
            g.setFont(new Font("黑体", Font.PLAIN, 30));
            char c = code.charAt(i);
            g.drawString(String.valueOf(c), 10 + i * 20, randowNum(random, height - 15, height - 5));
        }
        // 画随机线
        for (int i = 0; i < 2; i++) {
            g.setColor(new Color(randowNum(random, 50, 180), 
            randowNum(random, 50, 180), randowNum(random, 50, 180)));
            g.drawLine(randowNum(random, 0, width), randowNum(random, 0, height), 
            randowNum(random, 0, width), randowNum(random, 0, height));
        }
        return img;
    }
    private static int randowNum(Random random, int min, int max) {
        int num = 0;
        num = random.nextInt(max - min) + min;
        return num;
    }
    public static byte[] bufferedImage2ByteArray(BufferedImage image) throws IOException {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        ImageIO.write(image, "png", baos);
        return baos.toByteArray();
    }
}