You will need to make sure that the Java application can locate the PDFNetC library (PDFNetC.dll, libPDFNetC.so, or libPDFNetC.dylib). The easiest solution is to place the library in the following locations:
1. On Windows, place PDFNetC.dll to %WINDIR%\System32 or %WINDIR%\SysWOW64
2. On Linux, place libPDFNetC.so to /usr/lib
3. On Mac, place libPDFNetC.dylib to /Library/Java/Extensions.
Please keep in mind that you will need the same architecture of PDFNetC with the architecture of Java you are using. For example, 64-bit Java will only load 64-bit PDFNetC.