OSWorkflow审核流程代码，包含全部jar包和源码，重构了一下流程，使之更简洁，适合初学者。-OSWorkflow code review process, including all the jar files and source reconstruction process a bit, making it more compact, suitable for beginners.

使用spring构建一个简单的工作流引擎，便于初学者了解工作流引擎的开发模式。-The API discussed here is bundled as the main source code under the src/java directory. Three unit tests exist in the src/testdirectory including SimpleSequenceTestCase, RateDropTestCase and PoolingTes