问题
This is the eclipse .classpath file of the eclipse plugin program that I downloaded. 
I think that kind="src" and kind="output" is pretty straight forward, as they means the where the source java files and compiled class files are located. 
The kind="lib" seems to indicate the jar files the plugin is referencing, but I have something that I'm not sure about. 
- What does the 
kind="con"mean? - What is it for the 
exported="true"? I think in order to use this plugin, all the jar files that the plugin refers to should be exported, but only some of them are exported. 
    回答1:
1) In kind="con", the con stands for container, which is interpreted by eclipse as a classpath container. As described in that link:
A classpath container provides a way to indirectly reference a set of classpath entries through a classpath entry of kind CPE_CONTAINER
In other words, it enables grouping of other classpath entries in any way and re-use it wherever (including the ability of having different entries for different projects).
2) exported:
Say you have Project B that depends on Project C. The dependency is defined as exported=true. Then, another Project A that depends on Project B, will have also Project C present on A'a classpath.
回答2:
- kind="con" are indicating classpath containers
 - exported=true exports the dependency, meaning that any project that has a depedency on your project can see/access the exported dependencies as well.
 
来源:https://stackoverflow.com/questions/13960556/interpreting-eclipse-classpath-file-what-does-kind-con-and-exported-true