bytearray – Page 2 – Tarik Billa

Is there an equivalent to memcpy() in Java?

January 19, 2023 by Tarik

Use System.arraycopy() System.arraycopy(sourceArray, sourceStartIndex, targetArray, targetStartIndex, length); Example, String[] source = { “alpha”, “beta”, “gamma” }; String[] target = new String[source.length]; System.arraycopy(source, 0, target, 0, source.length); or use Arrays.copyOf() Example, target = Arrays.copyOf(source, length); java.util.Arrays.copyOf(byte[] source, int length) was added in JDK 1.6. The copyOf() method uses System.arrayCopy() to make a copy of the array, … Read more

How to convert a byte array to its numeric value (Java)?

January 10, 2023 by Tarik

One could use the Buffers that are provided as part of the java.nio package to perform the conversion. Here, the source byte[] array has a of length 8, which is the size that corresponds with a long value. First, the byte[] array is wrapped in a ByteBuffer, and then the ByteBuffer.getLong method is called to … Read more

How can I safely convert a byte array into a string and back? [duplicate]

January 7, 2023 by Tarik

The absolute safest way to convert bytes to a string and back is to use base64: string base64 = Convert.ToBase64String(bytes); byte[] bytes = Convert.FromBase64String(base64); That way you’re guaranteed not to get “invalid” unicode sequences such as the first half of a surrogate pair without the second half. Nothing’s going to decide to normalize the data … Read more

Byte Array to Hex String

January 7, 2023 by Tarik

Using str.format: >>> array_alpha = [ 133, 53, 234, 241 ] >>> print ”.join(‘{:02x}’.format(x) for x in array_alpha) 8535eaf1 or using format >>> print ”.join(format(x, ’02x’) for x in array_alpha) 8535eaf1 Note: In the format statements, the 02 means it will pad with up to 2 leading 0s if necessary. This is important since [0x1, … Read more

Fastest way to convert Image to Byte array

December 28, 2022 by Tarik

There is a RawFormat property of Image parameter which returns the file format of the image. You might try the following: // extension method public static byte[] imageToByteArray(this System.Drawing.Image image) { using(var ms = new MemoryStream()) { image.Save(ms, image.RawFormat); return ms.ToArray(); } }

Gets byte array from a ByteBuffer in java

December 27, 2022 by Tarik

Depends what you want to do. If what you want is to retrieve the bytes that are remaining (between position and limit), then what you have will work. You could also just do: ByteBuffer bb =.. byte[] b = new byte[bb.remaining()]; bb.get(b); which is equivalent as per the ByteBuffer javadocs.

Convert PIL Image to byte array?

December 23, 2022 by Tarik

Thanks everyone for your help. Finally got it resolved!! import io img = Image.open(fh, mode=”r”) roi_img = img.crop(box) img_byte_arr = io.BytesIO() roi_img.save(img_byte_arr, format=”PNG”) img_byte_arr = img_byte_arr.getvalue() With this i don’t have to save the cropped image in my hard disc and I’m able to retrieve the byte array from a PIL cropped image.

Byte[] to InputStream or OutputStream

December 9, 2022 by Tarik

You create and use byte array I/O streams as follows: byte[] source = …; ByteArrayInputStream bis = new ByteArrayInputStream(source); // read bytes from bis … ByteArrayOutputStream bos = new ByteArrayOutputStream(); // write bytes to bos … byte[] sink = bos.toByteArray(); Assuming that you are using a JDBC driver that implements the standard JDBC Blob interface … Read more

Java ByteBuffer to String

November 18, 2022 by Tarik

There is simpler approach to decode a ByteBuffer into a String without any problems, mentioned by Andy Thomas. String s = StandardCharsets.UTF_8.decode(byteBuffer).toString();

hexadecimal string to byte array in python

October 13, 2022 by Tarik

Suppose your hex string is something like >>> hex_string = “deadbeef” Convert it to a bytearray (Python 3 and 2.7): >>> bytearray.fromhex(hex_string) bytearray(b’\xde\xad\xbe\xef’) Convert it to a bytes object (Python 3): >>> bytes.fromhex(hex_string) b’\xde\xad\xbe\xef’ Note that bytes is an immutable version of bytearray. Convert it to a string (Python ≤ 2.7): >>> hex_data = hex_string.decode(“hex”) … Read more