Basically, all OA office systems are implemented in java, but there is no open source, and good ones are not open source.

From the functional application of OA, OA can be divided into five parts (basically all the following requirements are implemented in java):

Part I: Internal information publishing platform. Often include announcements, notices, press releases and other functions;

Part II: Internal communication platform. Including internal SMS, SMS, internal mail, external mail, internal forum and other functions;

The third part: administrative office management platform. There are many functions in it, such as office supplies management, vehicle management, meeting management, file management and so on.

The fourth part: document standardization management. In OA, it can be divided into personal file management and public file management. Since it is standardized management, the authority of this piece will be particularly clear.

Part V: Workflow automation. Workflow is the core of office automation. Without workflow, OA is not OA. The workflow in OA completely replaces the paper process in traditional office, which makes the process more standardized and improves the efficiency of process circulation and approval.