JAR Library: Export and Import

1. Export Library
   • Prepare source code
     • Create an Android project
     • Create source code, and fix all bug
     • Remove res/*
     • Remove unused source files
     • Edit AndroidManifest.xml to remove the statements that referes to resource, such as android:icon="@drwable/icon", android:label="@string/app_name"
   • Export library
     • On Package Explorer Panel of Eclipse, right-click the project, and select Export
     • Select Jave -> JAR file, then press "Next". At this time a dialog pops up.
     • On the right panel of "Select the resources to export:" group, unselect all items (such as .classpath, .project, AndroidManifest.xlm, default.properties), then press "Next"
     • Press "Next"
     • Press "Finish"
       
       Then the library is created.
       (Reference: Eclipse export jar files http://hi.baidu.com/etrigger/blog/item/e1fed134468b2fb2d0a2d3ad.html)
2. Import Library
   You can use a third party JAR in your application by adding it to your Eclipse project as follows:
   • In the Package Explorer panel, right-click on your project and select Properties.
   • Select Java Build Path, then the tab Libraries.
   • Press the Add External JARs... button and select the JAR file
   
   Alternatively, if you want to include third party JARs with your package, create a new directory for them within your project and select Add Library... instead.
   It is not necessary to put external JARs in the assets folder.
   (Reference: http://code.google.com/intl/zh-CN/android/kb/commontasks.html)