What should I note when I want to change Apache License 2.0 code?

Question

I need to copy org.apache.commons.net.ftp.FTPSClient and org.springframework.integration.ftp.session.DefaultFtpsSessionFactory, and refine some methods, What should I note in this case?

For example, do I need to copy the copyright? And is there anything else need attention?

Answer 1

Take a look at Apache License 2.0 . Under section 4 it's clearly defined what you have to do when you want to redistribute (changed) code.

You must give any other recipients of the Work or Derivative Works a copy of this License; and You must cause any modified files to carry prominent notices stating that You changed the files; and

Include the Apache License 2.0 to your work and add to the changed file that you have changed it.

You must retain, in the Source form of any Derivative Works that You distribute, all copyright, patent, trademark, and attribution notices from the Source form of the Work, excluding those notices that do not pertain to any part of the Derivative Works; and

Don't remove existing copyright, patent, trademarks and attribution notices.

If the Work includes a "NOTICE" text file as part of its distribution, then any Derivative Works that You distribute must include a readable copy of the attribution notices contained within such NOTICE file, excluding those notices that do not pertain to any part of the Derivative Works, in at least one of the following places: within a NOTICE text file distributed as part of the Derivative Works; within the Source form or documentation, if provided along with the Derivative Works; or, within a display generated by the Derivative Works, if and wherever such third-party notices normally appear. The contents of the NOTICE file are for informational purposes only and do not modify the License. You may add Your own attribution notices within Derivative Works that You distribute, alongside or as an addendum to the NOTICE text from the Work, provided that such additional attribution notices cannot be construed as modifying the License.

If the original work contains a NOTICE file you have to include a copy of it in your changed work.

If you follow these instructions you can modify code which is distributed under the Apache License as you pleased and distribute your work under every license you want without noticing anybody.