Jbpm bidirectional Object Management Mode

In jbpm, the relationship between objects is managed through relationmgr, which is very convenient for us to use, because it implements a multi-layer two-way management mode.
Let's take a look at its implementation principles: 1) relationmgr is the interface provided to us in this management mode, and we mainly deal with this class; 2) relationmgr references the referencemgr object, the object implements the specific management mode. 3) referencemgr is an interface that has two implementations: collectionmgr and propertymgr. The former manages the one-to-many relationship,
The latter manages the relationship between one-to-one (Multiple-to-one is handled in a unified manner with one-to-one). 4) collemgr Mgr has a subclass of mapmgr, which processes our commonly used map relationships. 5) propertymgr has a subclass of indexedpropertymgr to handle the case of index. 6) referencemgr implements specific functions through propertyaccessor. The latter stores the fields of an object and
The method is provided to retrieve the value of a field from an object. It can be seen that jbpm uses inheritance and reference very cleverly, and implements a two-way object management mode in a concise manner.