How to Use jdk APIs not included in the android sdk in android Development

How to Use jdk APIs not included in the android sdk in android Development

During Android development, you need to call a java API that does not exist in the android sdk and consider introducing jdk. Find a solution by studying the jdk package file and sdk file. I did not do this work, so it took a day to understand what was going on ~~~

Harvest: Find out the functions of each directory in the jdk installation directory and the directory structure of the android sdk Api package.

Solution: In the installation directory, a compressed package src.zip can be imported directly to Android ~~~~

Project -- ---buildpath---source--adexternaljar--select src.zip

In this way, we do not need to consider how to add the jdk source code to the android. jar package. -------- There is still a problem. The package can be imported normally. You can see the package, but you cannot browse the class in the package.