Damaged Pdf after setting content from a server response-CodePudding

I am currently making rest calls to a server for signing a pdf document.

I am sending a pdf(binary content) and retrieving the binary content of the signed pdf. When i get the binary content from the inputStream:

    try (InputStream inputStream = conn.getInputStream()) {
        if (inputStream != null) {
            try (BufferedReader br = new BufferedReader(new InputStreamReader(inputStream))) {
                String lines;
                while ((lines = br.readLine()) != null) {
                    output  = lines;
                }
            }
        }
    }

signedPdf.setBinaryContent(output.getBytes());

(signedPdf is a DTO with byte[] attribute) but when i try to set the content of the pdf with the content of the response pdf:

ByteArrayOutputStream out = new ByteArrayOutputStream();
out.write(signedPdf);
pdf.setContent(signedPdf);

and try to open it, it says that the pdf is damaged and cannot be repaired.

Anyone encountered something similar? Do i need to set the content-length as well for the output stream?

CodePudding user response：

PDF is binary data. One corrupts the PDF when reading as text (which in Java is always Unicode). Also it is a waste: a byte as char would double the memory usages, and there are two conversions: from bytes to String and vice versa, using some encoding. When converting from UTF-8 even UTF-8 format errors may be raised.

try (InputStream inputStream = conn.getInputStream()) {
    if (inputStream != null) {
        byte[] content = inputStream.readAllBytes();
        signedPdf.setBinaryContent(content);
    }
}

Whether to use a BufferedInputStream depends, for instance on the expected PDF size.

Furthermore new String(byte[], Charset) and String.getBytes(Charset) with explicit Charset (like StandardCharsets.UTF_8) are preferable over a default Charset overloaded version. Those use the current platform encoding, and hence delivers non-portable code. Behaving differently on an other platform/computer.