Java实现滑动验证码生成(后端工具类)

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;


@Data
@AllArgsConstructor
@NoArgsConstructor
public class ImageSlideVerify {

    private String bgImg;// 底部图片
    private String blockImg;// 滑块图片
    private Integer x;// 开始x
    private Integer y;// 开始y
    private Integer bound;// 误差值
}

import com.yang.domain.vo.ImageSlideVerify;
import org.apache.Tomcat.util.codec.binary.Base64;

import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.Transparency;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.Random;
import java.util.UUID;

import javax.imageio.ImageIO;


public class ImageSlideVerifyUtil {
	
	private static Integer x, y;// x , y轴起点位置
	private static Integer blockSize; // 块大小

	public static void main(String[] args) throws IOException {
		File file = new File("4.jpeg");
		cutting(file, 80);
		cutting(file);
	}
	
	
	// 切割
	public static ImageSlideVerify cutting(File file, int size) {
		FileInputStream fis;
		blockSize = size;
		
		try {
			fis = new FileInputStream(file);
			BufferedImage image = ImageIO.read(fis);// 将文件流转图像流
			
			// 生成圆位置
			Integer cp[] = circle();// 下标对应：上右下左
			
			// 生成滑块
			BufferedImage img = generateMin(image, image.getWidth(), image.getHeight(), size, cp);
			// 图片转base64
			String bgImg = imageToBase64(image);
			String blockImg = imageToBase64(img);
			// TODO 保存图片：用于测试，测试完毕删除
			// ImageIO.write(img, "png", new File("4-1.png"));
			// ImageIO.write(image, "png", new File("4-2.png"));
			
			ImageSlideVerify imageSlideVerify = new ImageSlideVerify(bgImg, blockImg, x, y, 3);

			return imageSlideVerify;
		} catch (IOException e) {
			e.printStackTrace();
		}
		return null;
	}
	// 切割
	public static ImageSlideVerify cutting(File file) {
		return cutting(file, 60);
	}
	
	// 圆的位置
	private static Integer[] circle() {
		
		Integer c[] = new Integer[4];// 四个位置有圆，0代表无，1代表有，下标对应上、右、下、左
		boolean flag = false;// 记录是否有圆
		while(!flag) {// 如果没有圆，则继续循环，至少要有一个圆(凸槽)
			for(int i = 0; i < 4; i++) {
				c[i] = new Random().nextInt(2);
				if(c[i] == 1) {
					flag = true;
				}
			}
		}
		return c;
	}
	
	
	private static BufferedImage generateMin(BufferedImage img, int width, int height, int size, Integer[] cp) throws IOException {

		
		int size1 = size + (size / 3 * 2);
		
		int maxX = width - ( size1 );
		int maxY = height - ( size1 );
		
		// 生成滑块开始位置
		x = new Random().nextInt(maxX);
		y = new Random().nextInt(maxY);
		// 创建滑块图像
		BufferedImage img1 = new BufferedImage(size1, size1, BufferedImage.TYPE_INT_RGB);
		Graphics2D gr = img1.createGraphics();
		// 图像背景透明
		img1 = gr.getDeviceConfiguration().createCompatibleImage(size1, size1, Transparency.TRANSLUCENT);
		
		// 拷贝rgb
		for(int i = 0; i < size1; i++) {
			for(int j = 0; j < size1; j++) {
				if(i < size / 3 || i > size + size / 3 || j < size / 3 || j > size + size / 3) {
					continue;
				}
				// 渲染RGB
				img1.setRGB(i, j, img.getRGB(i + x, j + y));
				// 将原图像素点覆盖白色
				Color color = new Color(255,255,255);
				img.setRGB(i + x, j + y, color.getRGB());
			}
		}
		// 设置圆(凸槽)
		setCircle(img, img1, x, y, cp);
		return img1;
	}
	
	private static void setCircle(BufferedImage oldImg, BufferedImage img, int x, int y, Integer[] cp) throws IOException {
		// 以白色覆盖原图像素点
		Color color = new Color(255,255,255);

		int d = blockSize / 3 + 2; // 直径
		int r = d / 2;// 半径
		
		if(cp[0] == 1) {// 上
			// 中心位置
			int w = img.getWidth() / 2;
			
			for(int i = w - r, r1 = 0; i < w + r; i++, r1++) {
				for(int j = 0, r2 = 0; j < d; j++, r2++) {
					
					if((r1 - r) * (r1 - r) + (r2 - r) * (r2 - 11) <= r * r) {
						if(oldImg.getRGB(x + i, y + j) == color.getRGB()) {
							continue;
						}
						img.setRGB(i, j, oldImg.getRGB(x + i, y + j));
						// 对应位置透明
						oldImg.setRGB(x + i, y + j, color.getRGB());
					}
				}
			}
		}
		if(cp[1] == 1) {// 右
			// 中心位置
			int h = img.getHeight() / 2;
			for(int i = img.getWidth() - d, r1 = 0; i < img.getWidth(); i++, r1++) {
				for(int j = h - r, r2 = 0; j < h + r; j++, r2++) {
					if((r1 - r) * (r1 - r) + (r2 - r) * (r2 - r) <= r * r) {
						if(oldImg.getRGB(x + i, y + j) == color.getRGB()) continue;
						img.setRGB(i, j, oldImg.getRGB(x + i, y + j));
						// 对应位置透明
						oldImg.setRGB(x + i, y + j, color.getRGB());
					}
				}
			}
		}
		if(cp[2] == 1) {// 下
			// 中心位置
			int w = img.getWidth() / 2;
			
			for(int i = w - r, r1 = 0; i < w + r; i++, r1++) {
				for(int j = img.getHeight() - d, r2 = 0; j < img.getHeight(); j++, r2++) {
					if((r1 - r) * (r1 - r) + (r2 - r) * (r2 - r) <= r * r) {
						if(oldImg.getRGB(x + i, y + j) == color.getRGB()) continue;
						img.setRGB(i, j, oldImg.getRGB(x + i, y + j));
						// 对应位置透明
						oldImg.setRGB(x + i, y + j, color.getRGB());
					}
				}
			}
		}
		if(cp[3] == 1) {// 左
			// 中心位置
			int h = img.getHeight() / 2;
			for(int i = 0, r1 = 0; i < d; i++, r1++) {
				for(int j = h - r, r2 = 0; j < h + r; j++, r2++) {
					if((r1 - r) * (r1 - r) + (r2 - r) * (r2 - r) <= r * r) {
						if(oldImg.getRGB(x + i, y + j) == color.getRGB()) continue;
						img.setRGB(i, j, oldImg.getRGB(x + i, y + j));
						// 对应位置透明
						oldImg.setRGB(x + i, y + j, color.getRGB());
					}
				}
			}
		}
	}

	
	private static String imageToBase64(BufferedImage img){
		ByteArrayOutputStream stream = new ByteArrayOutputStream();
		try {
			// 设置图片的格式
			ImageIO.write(img, "png", stream);
			byte[] bytes = Base64.encodeBase64(stream.toByteArray());
			String base64 = new String(bytes);
			return  "data:image/jpeg;base64,"+base64;
		} catch (IOException e) {
			e.printStackTrace();
		}
		return null;
	}
}