How to Convert a MySQL Blob to a Byte Array in Java?

Converting a MySQL Blob to a Byte Array

When working with a MySQL database in Java and you encounter a Blob datatype, you may need to convert it into a byte array for various purposes. Here's the most straightforward way to achieve this conversion:

The MySQL Blob class provides a convenient method called getBytes(). This method allows you to extract the Blob's content as a byte array. To use it, retrieve the Blob from your ResultSet as follows:

<code class="java">Blob blob = rs.getBlob("SomeDatabaseField");</code>

Next, calculate the length of the Blob using the length() method:

<code class="java">int blobLength = (int) blob.length();</code>

Finally, call the getBytes() method to obtain the Blob's content as a byte array:

<code class="java">byte[] blobAsBytes = blob.getBytes(1, blobLength);</code>

Remember to release the Blob object and free up memory once you have retrieved the byte array using the free() method:

<code class="java">blob.free();</code>

By following these steps, you can effortlessly convert a MySQL Blob into a byte array in your Java program.

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