Use of the Java build path in eclipse

1. In Eclipse, the project properties of the Java Build path under the Library tab, there are several buttons:
Add Jars ... Adding a jar package refers to the project currently contained in this eclipse, which is selected under the project list
Add External Jars ... Add the external jar, refers to the external, need to use the File Manager, on the computer hard disk selected.
Add Variable. Add variables, environment variables used by Eclipse's compile-time
Add Library ... Adding a library refers to a collection of already defined jars, as they are often
Add Class Folder ... To add a catalog of classes, refer to this Eclipse scope and select an interface under the project list.
Add External Folder ... Add the external class directory, you need to use the File Manager, on the computer hard disk selected.
Added jars and add External jars with the adding jar package from user libraries in the Add library,
2. Whether it will be scored in the final executable, depending on whether the order and export are selected!
3, a project, referencing other projects, can be in the project properties of the Java Build path under the projects tag add!
This reference does not break the source files in the referenced project into the executable file that is currently being generated by the project.
4, if you need to enter, you can use the source tag under link source (Browse ... The path of the referenced project) is complete.

Use of the Java build path in eclipse