java 将本地文件或网络文件与base64互相转换

一：将网络文件转为Base64

将文件转为base64

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public static String fileToBase64(String url){     int byteread = 0;     String total = null;     byte[] totalbyte = new byte[0];     try {         URL url = new URL(url);         URLConnection conn = url.openConnection();         InputStream inStream = conn.getInputStream();         byte[] buffer = new byte[1204];         while ((byteread = inStream.read(buffer)) != -1) {             //拼接流，这样写是保证文件不会被篡改             totalbyte = byteMerger(totalbyte,buffer,byteread);         }         inStream.close();     } catch (FileNotFoundException e) {         e.printStackTrace();     } catch (IOException e) {         e.printStackTrace();     }     return Base64.encodeBase64String(totalbyte) }

　　将base转为文件

　　

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public static void base64ToFile(String base64, String filePath) {         try {             byte[] bytes = Base64.decodeBase64(base64);             //base解密             File videoFile = new File(filePath);             //输入文件             FileOutputStream fos = new FileOutputStream(videoFile);             fos.write(bytes, 0, bytes.length);             fos.flush();             fos.close();         } catch (IOException e) {         }     }

　　

二：将本地文件转Base64

转Base64

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public static String videoToBase64(File videofilePath) {         long size = videofilePath.length();         byte[] imageByte = new byte[(int) size];         FileInputStream fs = null;         BufferedInputStream bis = null;         try {             fs = new FileInputStream(videofilePath);             bis = new BufferedInputStream(fs);             bis.read(imageByte);         } catch (FileNotFoundException e) {             e.printStackTrace();         } catch (IOException e) {             e.printStackTrace();         } finally {             if (bis != null) {                 try {                     bis.close();                 } catch (IOException e) {                     e.printStackTrace();                 }             }             if (fs != null) {                 try {                     fs.close();                 } catch (IOException e) {                     e.printStackTrace();                 }             }         }         return Base64.encodeBase64String(imageByte);     }

　　

将Base64转文件

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public static void base64ToFile(String base64, String filePath) {         try {             byte[] bytes = Base64.decodeBase64(base64);             //base解密             File videoFile = new File(filePath);             //输入文件             FileOutputStream fos = new FileOutputStream(videoFile);             fos.write(bytes, 0, bytes.length);             fos.flush();             fos.close();         } catch (IOException e) {         }     }

　　

注意：

在将文件转Base64字符时，如果使用sun下的BASE64Encoder时会导致转换出来的Base64自动换行，原因是RFC2045中有规定Base64一行不能超过76字符，超过则添加回车换行符所以导致转换出来的Base64字符会出现换行，解决方法是使用Apache的 commons-codec.jar，Base64.encodeBase64String(byte[]）得到的Base64字符不会出现换行

commons-codec 　　1.4版本时也会出现换行，使用1.8时不会出现换行，其他版本没有测试

 

<dependency>
    <groupId>commons-codec</groupId>
    <artifactId>commons-codec</artifactId>
    <version>1.8</version>
</dependency>