File轉成編碼成BASE64

    /**
     *
     * @param path
     * @return String
     * @description 將檔案轉base64字串
     * @date 2018年3月20日
     * @author changyl
     */
     import java.io.File;
     import java.io.FileInputStream;
     import java.io.IOException;
     import java.io.InputStream;
     import java.util.Base64;//我這裡的base64來自於jdk1.8
 

    public String fileToBase64(String path) {
        String base64 = null;
        InputStream in = null;
        try {
            File file = new File(path);
            in = new FileInputStream(file);
            byte[] bytes = new byte[in.available()];
            base64 = Base64.getEncoder().encodeToString(bytes);
        } catch
 
 (Exception e) {
            e.printStackTrace();
        } finally {
            if (in != null) {
                try {
                    in.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        return base64;
    }
 

BASE64解碼成File檔案

public static void base64ToFile(String base64, String fileName) {
        File file = null;
        //建立檔案目錄
        String filePath="D:\\image";
        File  dir=new File(filePath);
        if (!dir.exists() && !dir.isDirectory()) {
                dir.mkdirs();
        }
        BufferedOutputStream bos = null;
        java.io.FileOutputStream fos = null;
        try {
            byte[] bytes = Base64.getDecoder().decode(base64);
            file=new File(filePath+"\\"+fileName);
            fos = new java.io.FileOutputStream(file);
            bos = new BufferedOutputStream(fos);
            bos.write(bytes);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (bos != null) {
                try {
                    bos.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (fos != null) {
                try {
                    fos.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }

測試

public static void main(String[] args) {
         base64ToFile(fileToBase64("G:\\image\\2.jpg"), "2.jpg");
     }