I made a class diagram with PlantUML followed by the previou sequence diagram.
' Write comments after single quotaion mark. @startuml ' Color Setting skinparam classBorderColor black skinparam classArrowColor black skinparam noteBorderColor black skinparam classAttributeIconSize 0 ' Class Definition class ClassA { - privateMember : Integer + publicMember : Integer # protectedMember : Integer ~ packageMember : Integer + method() : void + {static} staticMethod() : void + {abstract} abstractMethod() : void } ' Note (For Class) note top of ClassA: Note note right of ClassA Note end note ' Interface interface Interface ClassA ..|> Interface ' Note(Linkに対して) note on link: Note ' Abstract Class abstract AbstractClass ClassA --|> AbstractClass ' Association ClassA -- ClassB ' Composition ClassA --* ClassC ' Aggregation class ClassD ClassA --o ClassD ' Dependency class ClassE ClassA ..> ClassE @enduml