In Lotus notes, we can create Java libries inside the designer and call it in any Java agents. Do any one know where the jar of there libries and agents are kept.
All code you write in Domino Designer or import into your database is stored in the database. It's not stored on the file system in any other way. So when you copy or replicate a database all the design elements, including your java code are copied / replicated just like all the other design elements (Forms, Views etc.)
Your code can reference external jars (i.e. using include com.foo.bar.*
) as long as they are they are listed in the client and server's JavaUserClasses notes.ini setting or are in the Notes/jvm/lib/ext dir.
Each Java library created from within Domino Designer is stored in a single "note" in the database NSF file. Within this note, the Java code is actually stored as multiple file attachments - a .java file and a (compiled) .class file. These are not exposed other than through the Java library editor in Domino Designer.
If you want/need to see more of the internal structure of how and where such design elements are stored, NotesPeek is a great utility for examining the internals of any NSF.