文件與base64相互轉換

package com.example.tool.controller;

import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;

/**
 * Created by LQ on 2021/9/2.
 */
public class FileToBase64 {
    public static void main(String[] args){
        try {
            String base64Code = encodeBase64File("F:/aa.docx");
            System.out.println("base64:"+base64Code);
            decoderBase64File(base64Code, "F:/def.docx");
            toFile(base64Code, "F:\\def.txt");
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    /**
     * 將文件轉成base64 字符串
     */
    public static String encodeBase64File(String path) throws Exception {
        File file = new File(path);
        FileInputStream inputFile = new FileInputStream(file);
//        byte[] buffer = new byte[(int) file.length()];
        byte[] buffer = new byte[inputFile.available()]; // 如果在網絡傳輸中存在弊端，數據可能分批次發送
        inputFile.read(buffer);
        inputFile.close();
        // 下面三種方式都可以將字節數組轉為base64
        String base64 = new BASE64Encoder().encode(buffer);// 此種方法base64存在換行
//        String base64 = Base64Util.convertByteArrayToBase64String(buffer);
//        String base64 = Base64.encodeBase64String(buffer);
        return  base64;

    }
    /**
     * 將base64字符解碼保存文件
     */

    public static void decoderBase64File(String base64Code, String targetPath) throws Exception {
        byte[] buffer = new BASE64Decoder().decodeBuffer(base64Code);
        FileOutputStream out = new FileOutputStream(targetPath);
        out.write(buffer);
        out.close();

    }

    /**
     * 將base64字符保存文本文件
     */

    public static void toFile(String base64Code, String targetPath) throws Exception {
        byte[] buffer = base64Code.getBytes();
        FileOutputStream out = new FileOutputStream(targetPath);
        out.write(buffer);
        out.close();
    }

}