> For the complete documentation index, see [llms.txt](https://hanfak.gitbook.io/workspace/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://hanfak.gitbook.io/workspace/integration/libraries.md). # Libraries * Callng code from other code sources that are not your own, is integrating a dependency into your application. * Calling a method in a library that has been imported on to the classpath, is similar to calling a http api endpoint ## Benefits * Reduce writing code over and over again * Faster response than http call over network, if doing the same thing, as there is network latency * although depends if that library calls something over the network (ie it is a client for a service) * Dependable, as a http service might be down or slow network, but the library is shipped with your code so will always be there * Algorithms used can be far more efficient and correct than yours, thus reducing time for creating this to spend on app specific code * Maintains a specific way of doing something ## Downsides * Need to wait for others to update, if there are issues or you need a new feature, or you did it and waiting for it to be added to new version * Need to manage the versions, issues with transitive dependencies * Use of build tools like maven/gradle helps * If a new version is out, you need to manually update yourself * Can have plugins in maven to check for latest * Can get locked in to libraries if not careful * use of clean architecture/ DIP and being very sure that it is necessary for key areas of code base * Can be massive libraries where you used a few things, leads to code bloat * Can copy and paste the code * monkey patch * May need to adapt the code to meet your needs, this can lead to ownership of code (time to learn etc) * Issues with open source libraries, not maintained, does not meet company polices etc ## Creating libraries check curl library * Modularise – make the library single purpose * Ensure that the consumers are local * Document it well, as though it’s a larger library * Stop before it gets too diverse/entangled * Avoid putting service business logic into the library ## Links