Type mismatch: cannot convert from ByteMatrix to BitMatrix

Question

I am creating a QR code generator program in JAVA using ZXING library. The program is

import com.google.zxing.BarcodeFormat;
import com.google.zxing.WriterExcept         


        

Answer 1

According to the javadoc here and the source code here, the QRCodeWriter.encode methods return a BitMatrix, not a ByteMatrix. So, that compilation error should not occur.

Unless ....

... you are using some version¹ of the com.google.zxing library that is incompatible with those javadocs. Check where you got your zxing JAR file from.

Despite searching, I haven't been able to find the version with this incompatibility. However:

1. I note that the official library has been forked many times on GitHub, and any one of those could be the source of the incompatibility.

2. I found this which clearly a fork, and clearly has tweaked encode. However, the people who did this have at least had the good sense to change the package name!

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I don't know if this is relevant, but it appears that in the C# version of this API, the QRCodeWriter.encode method does return a ByteMatrix; see here for evidence. Maybe you've stumbled across someone's misguided attempt to "fix" the Java API to match the C# API.