base64数据图片处理

base64数据图片处理

1.spring boot post请求数据过大：

server:
	tomcat:
    	max-http-form-post-size: -1
spring:
    http:
        multipart:
        max-file-size: -1
        max-request-size: -1

2.base64转png

/**
 * base64字符串转化成图片
 *
 * @param imgData
 *            图片编码
 * @param imgFilePath
 *            存放到本地路径
 * @return
 * @throws IOException
 */
@SuppressWarnings("finally")
public static boolean GenerateImage(String imgData, String imgFilePath) { // 对字节数组字符串进行Base64解码并生成图片
    if (imgData == null) // 图像数据为空
        return false;
    BASE64Decoder decoder = new BASE64Decoder();
    OutputStream out = null;
    try {
        out = new FileOutputStream(imgFilePath);
        // Base64解码
        byte[] b = decoder.decodeBuffer(imgData);
        for (int i = 0; i < b.length; ++i) {
            if (b[i] < 0) {// 调整异常数据
                b[i] += 256;
            }
        }
        out.write(b);
    } catch (FileNotFoundException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } finally {
        try {
            out.flush();
            out.close();
        } catch (IOException e) {

        }
        return true;
    }
}

3.图片旋转任意角度

/**
 * 创建任意角度的旋转图像
 * @param image
 * @param theta
 * @param backgroundColor
 * @return
 */
public static BufferedImage rotateImage(BufferedImage image, double theta, Color backgroundColor) {
    int width = image.getWidth();
    int height = image.getHeight();
    double angle = theta * Math.PI / 360; // 度转弧度
    double[] xCoords = getX(width / 2, height / 2, angle);
    double[] yCoords = getY(width / 2, height / 2, angle);
    int WIDTH = (int) (xCoords[3] - xCoords[0]);
    int HEIGHT = (int) (yCoords[3] - yCoords[0]);
    BufferedImage resultImage = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_ARGB);
    for (int i = 0; i < WIDTH; i++) {
        for (int j = 0; j < HEIGHT; j++) {
            int x = i - WIDTH / 2;
            int y = HEIGHT / 2 - j;
            double radius = Math.sqrt(x * x + y * y);
            double angle1;
            if (y > 0) {
                angle1 = Math.acos(x / radius);
            } else {
                angle1 = 2 * Math.PI - Math.acos(x / radius);
            }
            x = (int) (radius * Math.cos(angle1 - angle));
            y = (int) (radius * Math.sin(angle1 - angle));
            if (x < (width / 2) & x > -(width / 2) & y < (height / 2) & y > -(height / 2)) {
                int rgb = image.getRGB(x + width / 2, height / 2 - y);
                resultImage.setRGB(i, j, rgb);
            }else {
                int rgb = ((0 & 0xff) << 24) | ((backgroundColor.getRed() & 0xff) << 16) | ((backgroundColor.getGreen() & 0xff) << 8)
                        | ((backgroundColor.getBlue() & 0xff));
                resultImage.setRGB(i, j, rgb);
            }
        }
    }
    return resultImage;
}

// 获取四个角点旋转后Y方向坐标
private static double[] getY(int i, int j, double angle) {
    double results[] = new double[4];
    double radius = Math.sqrt(i * i + j * j);
    double angle1 = Math.asin(j / radius);
    results[0] = radius * Math.sin(angle1 + angle);
    results[1] = radius * Math.sin(Math.PI - angle1 + angle);
    results[2] = -results[0];
    results[3] = -results[1];
    Arrays.sort(results);
    return results;
}

// 获取四个角点旋转后X方向坐标
private static double[] getX(int i, int j, double angle) {
    double results[] = new double[4];
    double radius = Math.sqrt(i * i + j * j);
    double angle1 = Math.acos(i / radius);
    results[0] = radius * Math.cos(angle1 + angle);
    results[1] = radius * Math.cos(Math.PI - angle1 + angle);
    results[2] = -results[0];
    results[3] = -results[1];
    Arrays.sort(results);
    return results;
}