AWS lambda (server less) file upload using java

Question

I'm trying to upload file to AWS S3 bucket using Lambda server less application written in Java.

I'm hitting the endpoint with file using postman option binary (screenshot attached).

And I'm receiving binary content as string in my endpoint like as follows (screenshot attached).

I'm trying to convert this binary string to byte array and upload to S3 bucket.

I'm getting success response, But when i downloads the file / image it's looks like not an actual file.

Sample code:

@Override
public ServerlessOutput handleRequest(ServerlessInput serverlessInput, Context context) {
    ServerlessOutput output = new ServerlessOutput();
    String keyName = UUID.randomUUID().toString();
    String content = serverlessInput.getBody();
    byte[] encoded = this.toBinary(content).getBytes();
    ObjectMetadata metadata = new ObjectMetadata();
    metadata.setContentLength(encoded.length);
    metadata.setContentType(PNG_MIME);
    s3.putObject(new PutObjectRequest(
        ARTICLE_BUCKET_NAME,
        keyName,
        new ByteArrayInputStream(encoded),
        metadata)
    );
    output.setBody("Successfully inserted article ");
}

private String toBinary(String data) {
    byte[] bytes = data.getBytes();
    StringBuilder binary = new StringBuilder();
    for (byte b : bytes) {
        int val = b;
        for (int i = 0; i < 8; i++) {
            binary.append((val & 128) == 0 ? 0 : 1);
            val <<= 1;
        }
        binary.append(' ');
    }
    return binary.toString();
}