private ContentMetadata decodeFromInstructionFile()

in src/main/java/software/amazon/encryption/s3/internal/ContentMetadataDecodingStrategy.java [227:252]

• 20 lines of code
• 3 McCabe index (conditional complexity)

    private ContentMetadata decodeFromInstructionFile(GetObjectRequest request, GetObjectResponse response) {
        GetObjectRequest instructionGetObjectRequest = GetObjectRequest.builder()
                .bucket(request.bucket())
                .key(request.key() + INSTRUCTION_FILE_SUFFIX)
                .build();

        ResponseInputStream<GetObjectResponse> instruction;
        try {
            instruction = instructionFileConfig_.getInstructionFile(instructionGetObjectRequest);
        } catch (CompletionException | S3EncryptionClientException | NoSuchKeyException exception) {
            // This happens when the customer is attempting to decrypt an object
            // which is not encrypted with the S3 EC,
            // or instruction files are disabled,
            // or the instruction file is lost.
            throw new S3EncryptionClientException("Exception encountered while fetching Instruction File. Ensure the object you are" +
                    " attempting to decrypt has been encrypted using the S3 Encryption Client and instruction files are enabled.", exception);
        }

        Map<String, String> metadata = new HashMap<>();
        JsonNodeParser parser = JsonNodeParser.create();
        JsonNode objectNode = parser.parse(instruction);
        for (Map.Entry<String, JsonNode> entry : objectNode.asObject().entrySet()) {
            metadata.put(entry.getKey(), entry.getValue().asString());
        }
        return readFromMap(metadata, response);
    }