java-如何获取文件的base64?
作者:互联网
我尝试使用下面的代码为文件生成base64并以字符串形式返回.如果文件很小,我就可以得到.
StringBuffer output = new StringBuffer();
Process p;
try {
p = Runtime.getRuntime().exec(command);
p.waitFor();
BufferedReader reader =
new BufferedReader(new InputStreamReader(p.getInputStream()));
String line = "";
while ((line = reader.readLine())!= null) {
output.append(line + "\n");
}
} catch (Exception e) {
e.printStackTrace();
}
return output.toString();
如果还有其他方法来获取文件的base64.我传递的命令是base64文件名.请告诉我
解决方法:
您不需要为此使用外部程序,Java具有内置的Base64编码/解码功能.
这就是所有步骤:
String base64 = DatatypeConverter.printBase64Binary(Files.readAllBytes(
Paths.get("path/to/file")));
编辑:
如果您使用的是Java 6,则无法使用“文件和路径”(它们是在Java 7.0中添加的).这是与Java 6兼容的解决方案:
File f = new File("path/to/file");
byte[] content = new byte[(int) f.length()];
InputStream in = null;
try {
in = new FileInputStream(f);
for (int off = 0, read;
(read = in.read(content, off, content.length - off)) > 0;
off += read);
String base64 = DatatypeConverter.printBase64Binary(content);
} catch (IOException e) {
// Some error occured
} finally {
if (in != null)
try { in.close(); } catch (IOException e) {}
}
标签:base64,file-io,email,mime-types,java 来源: https://codeday.me/bug/20191029/1958241.html