Download JD-GUI to open JAR file and explore Java source code file (.class .java)
Click menu "File → Open File..." or just drag-and-drop the JAR file in the JD-GUI window libtiff-ndk26-shared-with-shared-deps-4.6.0-beta-6.jar file.
Once you open a JAR file, all the java classes in the JAR file will be displayed.