android - 如何将base64转换为pdf？

Question

给定一个 base64 输入，我如何在 Android 中将其转换为 PDF 文件？

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        context = this;
        setContentView(R.layout.activity_main);
        // Get the PDF file to encode it into Base64
        File file = new File("/mnt/sdcard/download/Base64.pdf");
        try {
            // Files is from Guava library
            Files.toByteArray(file);
            // Encoded into Base64
            byte[] temp = Base64.encode(Files.toByteArray(file), Base64.DEFAULT);
            // For testing purposes, wrote the encoded string to file
            writeToFile(Base64.encodeToString(temp, Base64.DEFAULT).toString());

        } catch (IOException e) {
            Log.d(tag, "File.toByteArray() error");
            e.printStackTrace();
        }
    }

我能够使用 http://www.webutils.pl/index.php?idx=base64测试 PDF 文件是否被正确编码。但我希望自己能够将 base64 解码回 PDF。我该怎么做？

编辑 1

按照 Saneesh CS 的建议尝试了以下代码

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        context = this;
        setContentView(R.layout.activity_main);
        // Get the PDF file to encode it into Base64
        File file = new File("/mnt/sdcard/download/Base64.pdf");
        try {
            // Files is from Guava library
            Files.toByteArray(file);
            // Encoded into Base64
            byte[] temp = Base64.encode(Files.toByteArray(file), Base64.DEFAULT);
            // Tried with the below line, but same result.
            byte[] temp1 = Base64.encode(Files.toByteArray(file), 0);
            // For testing purposes, wrote the encoded string to file
//          writeToFile(Base64.encodeToString(temp, Base64.DEFAULT).toString());
            final File dwldsPath = new File(Environment.getExternalStorageDirectory(), "test7.pdf");
            byte[] pdfAsBytes = Base64.decode(temp, 0);
            FileOutputStream os;
            os = new FileOutputStream(dwldsPath, false);
            os.write(pdfAsBytes);
            os.flush();
            os.close();
        } catch (IOException e) {
            Log.d(tag, "File.toByteArray() error");
            e.printStackTrace();
        }
    }

以上代码有效。

Answer 1

final File dwldsPath = new File(DOWNLOADS_FOLDER + fileName + ".pdf");
byte[] pdfAsBytes = Base64.decode(txt, 0);
FileOutputStream os;
os = new FileOutputStream(dwldsPath, false);
os.write(pdfAsBytes);
os.flush();
os.close();

试试这段代码。 txt是base64编码的字符串。