Package com.hp.ucmdb.api.topology

Interface QueryLink<QL extends QueryLink<QL>>

Type Parameters:
QL - The query link actual interface type, used for method chaining.
All Superinterfaces:
SupportsInvisibility<QueryLink<QL>>
All Known Subinterfaces:
DirectLink, IndirectLink, OnPropertiesLink
public interface QueryLink<QL extends QueryLink<QL>> extends SupportsInvisibility<QueryLink<QL>>
A link in the query definition.

A link in the query definition may add to the result, be used to constraint the result or both.
A link has:

  • A name, which has a default value (see name()).
  • Two important designated nodes: "source" and "target" ("from" and "to"). These designations may refer to different nodes on the query definition, or may refer to the same node (self link).
  • Invisibility status - an invisible link acts only as a condition on its connected nodes, while a visible link both acts as a condition and enriches the result with (one or more) Relations.
    It is meaningless to define an invisible link with minimum cardinality of 0 and unbounded maximum cardinality (UNBOUNDED), since that link will not restrict any adjacent query node.

Cardinality

In addition to conditions and information about the link itself, a query link is also a part of two expression trees - the source node expression tree and the target node expression tree.

By default, a link is added with an "and" condition to the top of both expression trees, with cardinality 1..* (unbounded), which is the same as saying:
"A CI is valid as a result of the source node only if there is at least one outgoing link between it and a CI matching the target node. A CI is valid as a result of the target node only if there is at least one incoming link between it and a CI matching the source node."

These conditions may be changed either:

  • Using broad range cardinality-setters (from this interface), which effect all the instances of the link in the relevant node expression tree.
  • Writing an explicit expression tree using and setting it to the node. Using this method allows for complex logical expressions, with multiple instances of each query link and different cardinality settings for each of these instances.
Since:
UCMDB 9.0

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final int
    UNBOUNDED
    Represents an unbounded cardinality value.

  • Method Summary

    Modifier and Type
    Method
    Description
    DirectLink
    asDirectLink()
    Returns this object as a DirectLink.
    IndirectLink
    asIndirectLink()
    Returns this object as an IndirectLink.
    OnPropertiesLink
    asOnPropertiesLink()
    Returns this object as an OnPropertiesLink.
    QL
    atLeast(int minSourceCardinality)
    Replaces the minimum cardinality of all instances of this query link in the source expression tree with the new values.
    QL
    atMost(int maxSourceCardinality)
    Replaces the maximum cardinality of all instances of this query link in the source expression tree with the new value.
    Integer
    elementNumber()
     
    QL
    exactly(int sourceCardinality)
    Replaces the minimum cardinality of all instances of this query link in the source expression tree with the new value.
    QueryNode
    getFromNode()
    Deprecated.
    use sourceNode().
    QueryNode
    getToNode()
    Deprecated.
    use targetNode().
    String
    name()
    The name of this link in the query definition it belongs to.
    QueryLinkType
    queryLinkType()
    The link type.
    QL
    restrictToSelfLinks()
    Sets the self link filter to "restrict to self links" mode.
    SelfLinkFilter
    selfLinkFilter()
    Returns the self link filter.
    QL
    setSelfLinkFilter(SelfLinkFilter selfLinkMode)
    Sets the self link filter.
    int
    sourceMaxCardinality()
    Returns the maximum of all of the maximum cardinalities set for this query link in the source expression tree.
    int
    sourceMinCardinality()
    Returns the minimum of all of the minimum cardinalities set for this query link in the source expression tree.
    QueryNode
    sourceNode()
    Returns the node the link of this link comes from.
    int
    targetMaxCardinality()
    Returns the maximum of all of the maximum cardinalities set for this query link in the target expression tree.
    int
    targetMinCardinality()
    Returns the minimum of all of the minimum cardinalities set for this query link in the target expression tree.
    QueryNode
    targetNode()
    Returns the node the link of this link goes to.
    QL
    withElementNumber(Integer elementNumber)
     
    QL
    withName(String name)
    Sets the name of this link.
    Setting the name does not change any bind-by-name resource (non-query definition resources) to match the new name.
    Changing the name changes the #hashCode of this object.
    QL
    withoutSelfLinks()
    Sets the self link filter to "restrict to non-self links" mode.
    QL
    withSourceCardinality(int minimumCardinality, int maximumCardinality)
    Replaces the cardinality of all instances of this query link in the source expression tree with the new values.
    QL
    withTargetCardinality(int minimumCardinality, int maximumCardinality)
    Replaces the cardinality of all the instances of this query link in the target expression tree with the new values.

    Methods inherited from interface com.hp.ucmdb.api.topology.SupportsInvisibility

    invisible, isInvisible

  • Field Details

    • UNBOUNDED

      static final int UNBOUNDED
      Represents an unbounded cardinality value.
      See Also:

  • Method Details

    • name

      String name()
      The name of this link in the query definition it belongs to.
      See Also:

    • withName

      QL withName(String name)
      Sets the name of this link.
      Setting the name does not change any bind-by-name resource (non-query definition resources) to match the new name.
      Changing the name changes the #hashCode of this object.
      Returns:
      this object. The returned object can be used for method chaining.
      See Also:

    • withElementNumber

      QL withElementNumber(Integer elementNumber)

    • elementNumber

      Integer elementNumber()

    • getFromNode

      @Deprecated QueryNode getFromNode()
      Deprecated.
      use sourceNode().
      Returns the node the link of this link comes from.

    • sourceNode

      QueryNode sourceNode()
      Returns the node the link of this link comes from.

    • getToNode

      @Deprecated QueryNode getToNode()
      Deprecated.
      use targetNode().
      Returns the node the link of this link goes to.

    • targetNode

      QueryNode targetNode()
      Returns the node the link of this link goes to.

    • withSourceCardinality

      QL withSourceCardinality(int minimumCardinality, int maximumCardinality)
      Replaces the cardinality of all instances of this query link in the source expression tree with the new values.
      Parameters:
      minimumCardinality - the minimum number of links.
      maximumCardinality - the maximum number of links.
      Returns:
      this object. The returned object can be used for method chaining.

    • withTargetCardinality

      QL withTargetCardinality(int minimumCardinality, int maximumCardinality)
      Replaces the cardinality of all the instances of this query link in the target expression tree with the new values.
      Parameters:
      minimumCardinality - the minimum number of links.
      maximumCardinality - the maximum number of links.
      Returns:
      this object. The returned object can be used for method chaining.

    • sourceMinCardinality

      int sourceMinCardinality()
      Returns the minimum of all of the minimum cardinalities set for this query link in the source expression tree.

    • sourceMaxCardinality

      int sourceMaxCardinality()
      Returns the maximum of all of the maximum cardinalities set for this query link in the source expression tree.

    • targetMinCardinality

      int targetMinCardinality()
      Returns the minimum of all of the minimum cardinalities set for this query link in the target expression tree.

    • targetMaxCardinality

      int targetMaxCardinality()
      Returns the maximum of all of the maximum cardinalities set for this query link in the target expression tree.

    • atLeast

      QL atLeast(int minSourceCardinality)
      Replaces the minimum cardinality of all instances of this query link in the source expression tree with the new values.

      Equivalent to withSourceCardinality(minSourceCardinality, sourceMaxCardinality());

      Parameters:
      minSourceCardinality - the minimum number of links.
      Returns:
      this object. The returned object can be used for method chaining.

    • atMost

      QL atMost(int maxSourceCardinality)
      Replaces the maximum cardinality of all instances of this query link in the source expression tree with the new value.

      Equivalent to withSourceCardinality(sourceMinCardinality(), maxSourceCardinality);

      Parameters:
      maxSourceCardinality - the maximum number of links.
      Returns:
      this object. The returned object can be used for method chaining.

    • exactly

      QL exactly(int sourceCardinality)
      Replaces the minimum cardinality of all instances of this query link in the source expression tree with the new value.

      Equivalent to withSourceCardinality(sourceMinCardinality(), sourceMaxCardinality());

      Parameters:
      SourceCardinality - the minimum number of links.
      Returns:
      this object. The returned object can be used for method chaining.

    • queryLinkType

      QueryLinkType queryLinkType()
      The link type.
      Returns:
      the type of the link.

    • asDirectLink

      DirectLink asDirectLink() throws ClassCastException
      Returns this object as a DirectLink.
      Returns:
      this object as a DirectLink. If queryLinkType() is not QueryLinkType.DIRECT_LINK, a class cast exception is thrown.
      Throws:
      ClassCastException

    • asIndirectLink

      IndirectLink asIndirectLink() throws ClassCastException
      Returns this object as an IndirectLink.
      Returns:
      this object as an IndirectLink. If queryLinkType() is not QueryLinkType.INDIRECT_LINK, a class cast exception is thrown.
      Throws:
      ClassCastException

    • asOnPropertiesLink

      OnPropertiesLink asOnPropertiesLink() throws ClassCastException
      Returns this object as an OnPropertiesLink.
      Returns:
      this object as an OnPropertiesLink. If queryLinkType() is not QueryLinkType.ON_PROPERTIES_LINK, a class cast exception is thrown.
      Throws:
      ClassCastException

    • restrictToSelfLinks

      QL restrictToSelfLinks()
      Sets the self link filter to "restrict to self links" mode.

      Calling this method restricts links answering this QueryLink to have the same CI as both source and target. The CI can come from different QueryNodes, but its ID must be the same.

      Returns:
      this object. The returned object can be used for method chaining.

    • withoutSelfLinks

      QL withoutSelfLinks()
      Sets the self link filter to "restrict to non-self links" mode.

      Calling this method restricts links answering this QueryLink to links that do not have the same CI as both source and target. Links that start and end with the same CI, even if from different QueryNodes, will be omitted from the result of this QueryLink.

      Returns:
      this object. The returned object can be used for method chaining.

    • setSelfLinkFilter

      QL setSelfLinkFilter(SelfLinkFilter selfLinkMode)
      Sets the self link filter.

      The self link filter may, if set, filter self-links (identical source and target) or filter non-self links (different source and target).

      Returns:
      this object. The returned object can be used for method chaining.

    • selfLinkFilter

      SelfLinkFilter selfLinkFilter()
      Returns the self link filter.
      Returns:
      the self link filter.
      See Also: