Java 实现文件和base64字符串互转

       项目中遇到需要将图片转成base64编码的字符串的需求，但是，考虑到扩展性，写了一个可以转换任务类型文件的方法。需要引入的包:

        <dependency>
            <groupId>commons-codec</groupId>
            <artifactId>commons-codec</artifactId>
            <version>1.13</version>
        </dependency>

 

     源码如下：

import sun.misc.BASE64Decoder;

import sun.misc.BASE64Encoder;

 

 

import java.io.*;

 

 

public class Base64FileUtil {

 

 

    private static String targetFilePath = "E:\\base2Img\\target\\test.txt";

 

 

    public static void main(String[] args) throws Exception {

        String fileStr = getFileStr("E:\\base2Img\\big test.txt");

        System.out.println("fileStr ===" + fileStr);

        System.out.println(generateFile(fileStr, targetFilePath));

        System.out.println("end");

    }

 

 

    /**

     * 文件转化成base64字符串

     * 将文件转化为字节数组字符串，并对其进行Base64编码处理

     */

    public static String getFileStr(String filePath) {

        InputStream in = null;

        byte[] data = null;

        // 读取文件字节数组

        try {

            in = new FileInputStream(filePath);

            data = new byte[in.available()];

            in.read(data);

            in.close();

        } catch (IOException e) {

            e.printStackTrace();

        } finally {

            try {

                in.close();

            } catch (IOException e) {

                e.printStackTrace();

            }

        }

        // 对字节数组Base64编码

        BASE64Encoder encoder = new BASE64Encoder();

        // 返回 Base64 编码过的字节数组字符串

        return encoder.encode(data);

    }

 

 

    /**

     * base64字符串转化成文件，可以是JPEG、PNG、TXT和AVI等等

     *

     * @param base64FileStr

     * @param filePath

     * @return

     * @throws Exception

     */

    public static boolean generateFile(String base64FileStr, String filePath) throws Exception {

        // 数据为空

        if (base64FileStr == null) {

            System.out.println(" 不行，oops！ ");

            return false;

        }

        BASE64Decoder decoder = new BASE64Decoder();

 

 

        // Base64解码,对字节数组字符串进行Base64解码并生成文件

        byte[] byt = decoder.decodeBuffer(base64FileStr);

        for (int i = 0, len = byt.length; i < len; ++i) {

            // 调整异常数据

            if (byt[i] < 0) {

                byt[i] += 256;

            }

        }

        OutputStream out = null;

        InputStream input = new ByteArrayInputStream(byt);

        try {

            // 生成指定格式的文件

            out = new FileOutputStream(filePath);

            byte[] buff = new byte[1024];

            int len = 0;

            while ((len = input.read(buff)) != -1) {

                out.write(buff, 0, len);

            }

        } catch (IOException e) {

            e.printStackTrace();

        } finally {

            out.flush();

            out.close();

        }

        return true;

    }

 

}