一、简介
BASE64是一种编码方式,通常用于把二进制数据编码为可写的字符形式的数据。这是一种可逆的编码方式。它是一种能将任意Binary资料用64种字元组合成字串的方法,而这个Binary资料和字串资料彼此之间是可以互相转换的,十分方便。在实际应用上,Base64除了能将Binary资料可视化之外,也常用来表示字串加密过后的内容。
二、示例代码
(1)文件转base64。
/**
* 文件转base64字符串
* @param file
* @return
*/
public static String fileToBase64(File file) {
String base64 = null;
InputStream in = null;
try {
in = new FileInputStream(file);
byte[] bytes = new byte[in.available()];
int length = in.read(bytes);
base64 = Base64.encodeToString(bytes, 0, length, Base64.DEFAULT);
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} finally {
try {
if (in != null) {
in.close();
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
return base64;
}
(2)base64转文件。
/**
* base64字符串转文件
* @param base64
* @return
*/
public static File base64ToFile(String base64) {
File file = null;
String fileName = "/Petssions/record/testFile.amr";
FileOutputStream out = null;
try {
// 解码,然后将字节转换为文件
file = new File(Environment.getExternalStorageDirectory(), fileName);
if (!file.exists())
file.createNewFile();
byte[] bytes = Base64.decode(base64, Base64.DEFAULT);// 将字符串转换为byte数组
ByteArrayInputStream in = new ByteArrayInputStream(bytes);
byte[] buffer = new byte[1024];
out = new FileOutputStream(file);
int bytesum = 0;
int byteread = 0;
while ((byteread = in.read(buffer)) != -1) {
bytesum += byteread;
out.write(buffer, 0, byteread); // 文件写操作
}
} catch (IOException ioe) {
ioe.printStackTrace();
} finally {
try {
if (out!= null) {
out.close();
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
return file;
}
(3)CommonsMultipartFile 文件转base64。
/**
* file转base64
* @param imgFile 文件
* @return
*/
public static String GetImageBase64one(CommonsMultipartFile file) {
if(file == null || file.equals("")){
return "";
}
InputStream in = null;
byte[] data = null;
DiskFileItem fi = (DiskFileItem) file.getFileItem();
File file1=fi.getStoreLocation();
try {
in = new FileInputStream(file1);
data = new byte[in.available()];
in.read(data);
in.close();
} catch (IOException e) {
e.printStackTrace();
}
BASE64Encoder encoder = new BASE64Encoder();
String code = encoder.encode(data);
return code;
}