Class AbstractContext

    • Field Detail

      • data

        protected final JsonValue data
        The Context data.
    • Constructor Detail

      • AbstractContext

        protected AbstractContext​(Context parent,
                                  String name)
        Constructs a new AbstractContext with a null id.
        Parameters:
        parent - The parent context.
        name - The name of the context.
      • AbstractContext

        protected AbstractContext​(String id,
                                  String name,
                                  Context parent)
        Constructs a new AbstractContext.
        Parameters:
        id - The id of the context.
        parent - The parent context.
        name - The name of the context.
      • AbstractContext

        public AbstractContext​(JsonValue savedContext,
                               ClassLoader classLoader)
        Creates a new context from the JSON representation of a previously persisted context.

        Sub-classes MUST provide a constructor having the same declaration as this constructor in order to support persistence. Implementations MUST take care to invoke the super class implementation before parsing their own context attributes. Below is an example implementation for a security context which stores the user name and password of the authenticated user:

         protected SecurityContext(JsonValue savedContext, ClassLoader classLoader) {
             // Invoke the super-class implementation first.
             super(savedContext, classLoader);
        
             // Now parse the attributes for this context.
             this.username = savedContext.get("username").required().asString();
             this.password = savedContext.get("password").required().asString();
         }
         
        In order to create a context's persisted JSON representation, implementations must override.
        Parameters:
        savedContext - The JSON representation from which this context's attributes should be parsed.
        classLoader - The ClassLoader which can properly resolve the persisted class-name.
    • Method Detail

      • getContextName

        public final String getContextName()
        Description copied from interface: Context
        Get this Context's name.
        Specified by:
        getContextName in interface Context
        Returns:
        this object's name
      • asContext

        public final <T extends Context> T asContext​(Class<T> clazz)
        Description copied from interface: Context
        Returns the first context in the chain whose type is a sub-type of the provided Context class. The method first checks this context to see if it has the required type, before proceeding to the parent context, and then continuing up the chain of parents until the root context is reached.
        Specified by:
        asContext in interface Context
        Type Parameters:
        T - The context type.
        Parameters:
        clazz - The class of context to be returned.
        Returns:
        The first context in the chain whose type is a sub-type of the provided Context class.
      • as

        public final <T extends ContextOptional<T> as​(Class<T> clazz)
        Description copied from interface: Context
        Returns an @{link Optional} which contains the first context in the chain whose type is a sub-type of the provided Context class if one exists, or an empty optional if none is present. The method first checks this context to see if it has the required type, before proceeding to the parent context, and then continuing up the chain of parents until the root context is reached.
        Specified by:
        as in interface Context
        Type Parameters:
        T - The context type.
        Parameters:
        clazz - The class of context to be returned.
        Returns:
        An Optional containing the first context in the chain whose type is a sub-type of the provided Context class, or an empty optional if no such Context exists in the chain.
      • getContext

        public final Context getContext​(String contextName)
        Description copied from interface: Context
        Returns the first context in the chain whose context name matches the provided name.
        Specified by:
        getContext in interface Context
        Parameters:
        contextName - The name of the context to be returned.
        Returns:
        The first context in the chain whose name matches the provided context name.
      • get

        public Optional<Context> get​(String contextName)
        Description copied from interface: Context
        Returns an Optional containing the first context in the chain whose context name matches the provided name, or an empty Optional if none is present.
        Specified by:
        get in interface Context
        Parameters:
        contextName - The name of the context to be returned.
        Returns:
        An Optional containing the first context in the chain whose name matches the provided context name, an empty optional if none is present.
      • containsContext

        public final boolean containsContext​(Class<? extends Context> clazz)
        Description copied from interface: Context
        Returns true if there is a context in the chain whose type is a sub-type of the provided Context class. The method first checks this context to see if it has the required type, before proceeding to the parent context, and then continuing up the chain of parents until the root context is reached.
        Specified by:
        containsContext in interface Context
        Parameters:
        clazz - The class of context to be checked.
        Returns:
        true if there is a context in the chain whose type is a sub-type of the provided Context class.
      • containsContext

        public final boolean containsContext​(String contextName)
        Description copied from interface: Context
        Returns true if there is a context in the chain whose name matches the provided context name.
        Specified by:
        containsContext in interface Context
        Parameters:
        contextName - The name of the context to locate.
        Returns:
        true if there is a context in the chain whose context name matches contextName.
      • getId

        public final String getId()
        Description copied from interface: Context
        Returns the unique ID identifying this context, usually a UUID. If no ID has been defined then the ID of the parent context will be returned.
        Specified by:
        getId in interface Context
        Returns:
        The unique ID identifying this context. If no ID has been defined then the ID of the parent context will be returned.
      • getRootId

        public String getRootId()
        Description copied from interface: Context
        Returns the unique ID of the root context, usually a UUID.
        Specified by:
        getRootId in interface Context
        Returns:
        The unique ID of the root context.
      • getParent

        public final Context getParent()
        Description copied from interface: Context
        Returns the parent of this context.
        Specified by:
        getParent in interface Context
        Returns:
        The parent of this context, or null if this context is a root context.
      • isRootContext

        public final boolean isRootContext()
        Description copied from interface: Context
        Returns true if this context is a root context.
        Specified by:
        isRootContext in interface Context
        Returns:
        true if this context is a root context.
      • toJsonValue

        public JsonValue toJsonValue()
        Description copied from interface: Context
        Return this Context as a JsonValue (for persistence).
        Specified by:
        toJsonValue in interface Context
        Returns:
        the Context data as a JsonValue.