package com.jsh.erp.utils;
|
|
import javax.imageio.ImageIO;
|
import javax.servlet.http.HttpServletResponse;
|
import java.awt.*;
|
import java.awt.image.BufferedImage;
|
import java.io.ByteArrayOutputStream;
|
import java.io.IOException;
|
import java.util.Base64;
|
import java.util.Random;
|
|
/**
|
* 登录验证码工具类
|
*/
|
public class RandImageUtil {
|
|
public static final String key = "JEECG_LOGIN_KEY";
|
|
/**
|
* 定义图形大小
|
*/
|
private static final int width = 105;
|
/**
|
* 定义图形大小
|
*/
|
private static final int height = 35;
|
|
/**
|
* 定义干扰线数量
|
*/
|
private static final int count = 200;
|
|
/**
|
* 干扰线的长度=1.414*lineWidth
|
*/
|
private static final int lineWidth = 2;
|
|
/**
|
* 图片格式
|
*/
|
private static final String IMG_FORMAT = "JPEG";
|
|
/**
|
* base64 图片前缀
|
*/
|
private static final String BASE64_PRE = "data:image/jpg;base64,";
|
|
/**
|
* 直接通过response 返回图片
|
* @param response
|
* @param resultCode
|
* @throws IOException
|
*/
|
public static void generate(HttpServletResponse response, String resultCode) throws IOException {
|
BufferedImage image = getImageBuffer(resultCode);
|
// 输出图象到页面
|
ImageIO.write(image, IMG_FORMAT, response.getOutputStream());
|
}
|
|
/**
|
* 生成base64字符串
|
* @param resultCode
|
* @return
|
* @throws IOException
|
*/
|
public static String generate(String resultCode) throws IOException {
|
BufferedImage image = getImageBuffer(resultCode);
|
|
ByteArrayOutputStream byteStream = new ByteArrayOutputStream();
|
//写入流中
|
ImageIO.write(image, IMG_FORMAT, byteStream);
|
//转换成字节
|
byte[] bytes = byteStream.toByteArray();
|
//转换成base64串
|
String base64 = Base64.getEncoder().encodeToString(bytes).trim();
|
base64 = base64.replaceAll("\n", "").replaceAll("\r", "");//删除 \r\n
|
|
//写到指定位置
|
//ImageIO.write(bufferedImage, "png", new File(""));
|
|
return BASE64_PRE+base64;
|
}
|
|
private static BufferedImage getImageBuffer(String resultCode){
|
// 在内存中创建图象
|
final BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
|
// 获取图形上下文
|
final Graphics2D graphics = (Graphics2D) image.getGraphics();
|
// 设定背景颜色
|
graphics.setColor(Color.WHITE); // ---1
|
graphics.fillRect(0, 0, width, height);
|
// 设定边框颜色
|
// graphics.setColor(getRandColor(100, 200)); // ---2
|
graphics.drawRect(0, 0, width - 1, height - 1);
|
|
final Random random = new Random();
|
// 随机产生干扰线，使图象中的认证码不易被其它程序探测到
|
for (int i = 0; i < count; i++) {
|
graphics.setColor(getRandColor(150, 200)); // ---3
|
|
final int x = random.nextInt(width - lineWidth - 1) + 1; // 保证画在边框之内
|
final int y = random.nextInt(height - lineWidth - 1) + 1;
|
final int xl = random.nextInt(lineWidth);
|
final int yl = random.nextInt(lineWidth);
|
graphics.drawLine(x, y, x + xl, y + yl);
|
}
|
// 取随机产生的认证码
|
for (int i = 0; i < resultCode.length(); i++) {
|
// 将认证码显示到图象中,调用函数出来的颜色相同，可能是因为种子太接近，所以只能直接生成
|
// graphics.setColor(new Color(20 + random.nextInt(130), 20 + random
|
// .nextInt(130), 20 + random.nextInt(130)));
|
// 设置字体颜色
|
graphics.setColor(Color.BLACK);
|
// 设置字体样式
|
// graphics.setFont(new Font("Arial Black", Font.ITALIC, 18));
|
graphics.setFont(new Font("Times New Roman", Font.BOLD, 24));
|
// 设置字符，字符间距，上边距
|
graphics.drawString(String.valueOf(resultCode.charAt(i)), (23 * i) + 8, 26);
|
}
|
// 图象生效
|
graphics.dispose();
|
return image;
|
}
|
|
private static Color getRandColor(int fc, int bc) { // 取得给定范围随机颜色
|
final Random random = new Random();
|
if (fc > 255) {
|
fc = 255;
|
}
|
if (bc > 255) {
|
bc = 255;
|
}
|
|
final int r = fc + random.nextInt(bc - fc);
|
final int g = fc + random.nextInt(bc - fc);
|
final int b = fc + random.nextInt(bc - fc);
|
|
return new Color(r, g, b);
|
}
|
}
|
