wisdomisite-java/src/main/java/com/zhgd/xmgl/util/Base64Util.java

package com.zhgd.xmgl.util;

import cn.hutool.core.io.FileUtil;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.codec.binary.Base64;

import java.io.*;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.HashMap;
import java.util.Map;

@Slf4j
public class Base64Util {
    // 文件扩展名 -> MIME类型映射
    private static final Map<String, String> MIME_TYPES = new HashMap<>();

    static {
        // 图片
        MIME_TYPES.put(".jpg", "image/jpeg");
        MIME_TYPES.put(".jpeg", "image/jpeg");
        MIME_TYPES.put(".png", "image/png");
        MIME_TYPES.put(".gif", "image/gif");
        MIME_TYPES.put(".bmp", "image/bmp");
        MIME_TYPES.put(".webp", "image/webp");

        // 文档
        MIME_TYPES.put(".pdf", "application/pdf");
        MIME_TYPES.put(".txt", "text/plain");

        // Office
        MIME_TYPES.put(".doc", "application/msword");
        MIME_TYPES.put(".docx", "application/vnd.openxmlformats-officedocument.wordprocessingml.document");
        MIME_TYPES.put(".xls", "application/vnd.ms-excel");
        MIME_TYPES.put(".xlsx", "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
        MIME_TYPES.put(".ppt", "application/vnd.ms-powerpoint");
        MIME_TYPES.put(".pptx", "application/vnd.openxmlformats-officedocument.presentationml.presentation");

        // 压缩包
        MIME_TYPES.put(".zip", "application/zip");
        MIME_TYPES.put(".rar", "application/x-rar-compressed");
        MIME_TYPES.put(".7z", "application/x-7z-compressed");
    }

    public static String getURLImage(String imageUrl) {
        String base64String = "";
        try {
            //new一个URL对象
            URL url = new URL(imageUrl);
            //打开链接
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            //设置请求方式为"GET"
            conn.setRequestMethod("GET");
            //超时响应时间为5秒
            conn.setConnectTimeout(20 * 1000);
            conn.setReadTimeout(20 * 1000);
            //通过输入流获取图片数据
            InputStream inStream = conn.getInputStream();
            //得到图片的二进制数据，以二进制封装得到数据，具有通用性
            byte[] data = readInputStream(inStream);
            base64String = Base64.encodeBase64String(data);

        } catch (Exception e) {
            log.error("error：", e);
        }
        return base64String;
    }

    /**
     * 本地文件（图片、excel等）转换成Base64字符串
     *
     * @param imgPath
     */
    public static String convertFileToBase64(String imgPath) {
        byte[] fileBytes = FileUtil.readBytes(imgPath);
        return Base64.encodeBase64String(fileBytes);
    }

    /**
     * 本地文件（图片、excel等）转换成Base64字符串（带前缀）
     *
     * @param filePath
     * @return
     */
    public static String convertFileToBase64WithPrefix(String filePath) {
        String base64 = convertFileToBase64(filePath);
        String fileExt = getFileExtension(filePath).toLowerCase();

        // 获取对应的MIME类型，默认使用application/octet-stream
        String mimeType = MIME_TYPES.getOrDefault(fileExt, "application/octet-stream");
        return "data:" + mimeType + ";base64," + base64;
    }

    /**
     * 获取文件扩展名（带点）
     */
    private static String getFileExtension(String filename) {
        int dotIndex = filename.lastIndexOf('.');
        return (dotIndex == -1) ? "" : filename.substring(dotIndex);
    }

    public static String getFileToBase64(String imgPath) {
        if (imgPath.indexOf("http") >= 0) {
            return getURLImage(imgPath);
        } else {
            return convertFileToBase64(imgPath);
        }
    }

    private static byte[] readInputStream(InputStream inStream) throws Exception {
        ByteArrayOutputStream outStream = new ByteArrayOutputStream();
        //创建一个Buffer字符串
        byte[] buffer = new byte[1024];
        //每次读取的字符串长度，如果为-1，代表全部读取完毕
        int len = 0;
        //使用一个输入流从buffer里把数据读取出来
        while ((len = inStream.read(buffer)) != -1) {
            //用输出流往buffer里写入数据，中间参数代表从哪个位置开始读，len代表读取的长度
            outStream.write(buffer, 0, len);
        }
        //关闭输入流
        inStream.close();
        //把outStream里的数据写入内存
        return outStream.toByteArray();
    }


    public static File convertBase64ToFile(String fileBase64String, String filePath, String fileName) {
        BufferedOutputStream bos = null;
        FileOutputStream fos = null;
        File file;
        try {
            File dir = new File(filePath);
            // 判断文件目录是否存在
            if (!dir.exists()) {
                FileUtil.mkdir(dir);
            }
            java.util.Base64.Decoder decoder = java.util.Base64.getMimeDecoder();

            //BASE64Decoder decoder = new BASE64Decoder();
            //byte[] bfile = decoder.decodeBuffer(fileBase64String);
            byte[] bfile = decoder.decode(fileBase64String);
            file = new File(filePath + File.separator + fileName);
            fos = new FileOutputStream(file);
            bos = new BufferedOutputStream(fos);
            bos.write(bfile);
            return file;
        } catch (Exception e) {
            log.error("error：", e);
            return null;
        } finally {
            if (bos != null) {
                try {
                    bos.close();
                } catch (IOException e1) {
                    e1.printStackTrace();
                }
            }
            if (fos != null) {
                try {
                    fos.close();
                } catch (IOException e1) {
                    e1.printStackTrace();
                }
            }
        }
    }


}