net.corda.v5.membership

The corda-membership package defines interfaces that provide information about a member Corda identity that has been granted admission to a membership group. Synonym for a virtual node or group member. and a membership group A logical grouping of multiple Corda identities, which communicate and transact with each other using a specific set of CorDapps. . The interfaces in this module should not be implemented by CorDapp Corda Distributed Application. A Java (or any JVM targeting language) application built using the Corda build toolchain and CorDapp API to solve some problem that is best solved in a decentralized manner. Developers. Instead, instances can be retrieved through lookup services. For more information, see the documentation for the package in the Java API documentation.

This package consists primarily of the following two root classes:

• MemberInfo
• GroupParameters

MemberInfo

The MemberInfo interface exposes properties of a virtual node’s membership. This includes the X.500 A series of international standards defining a global directory service protocol for computer networks. It provides a structured framework for storing, accessing, and managing information about network resources and users in a hierarchical and distributed manner. name, ledger keys A key which can be used to sign for transactions. This key may be held confidentially and signatures may be used as evidence of authority to sign transactions. Alternatively, it may be published in the virtual nodes's MemberInfo to act as a published fact to prove the identity of the virtual node on the ledger. , and status. This information is a combination of information provided during network registration and metadata assigned to the member by the MGM Membership Group Manager. May also be referred to as the Network Manager. It is a virtual node and Corda identity that acts as a central registrar for group membership. .

Information provided by the virtual node operator at time of registration is the content of the MemberContext and the information provided by the MGM is the source of the MGMContext content.

Instances of MemberInfo must be retrieved through a lookup API. MemberLookup from the corda-application module, is the lookup API which provides membership information to CorDapps. This can be used to look up the information of the member executing a flow Communication between participants in an application network is peer-to-peer using flows. or other members available to transact with within the group.

The MemberInfo interface extends the LayeredPropertyMap interface, which means that membership information is key-value String pairs that are parsed and returned through properties. Generally, any properties required for use within a CorDapp are exposed through the MemberInfo interface. Other properties may only be relevant internally or at certain layers within the codebase so these are exposed through extension functions.

GroupParameters

The GroupParameters interface is also a type of LayeredPropertyMap which exposes properties of the group as distributed by the network manager (MGM). These properties define the parameters under which all members must operate during transactions and are exposed for Network Operators by GET methods. For more information, see Updating Group Parameters.

The GroupParametersLookup interface allows flows to access GroupParameters for further verification.