Class UsageGraph

  • All Implemented Interfaces:

    public class UsageGraph
    extends Object
    implements NodeVisitorAcceptor
    See DCD
    A UsageGraph tracks usage references between Java classes, based upon a parsing of the class files. Once the UsageGraph is built, it may be visited to perform additional post-processing, or usage relationship analysis.

    The UsageGraph is composed of ClassNodes. Each ClassNode has various MemberNodes, specifically ConstructorNodes, FieldNodes, and MethodNodes. Each of these MemberNodes keeps track of other MemberNodes which it uses and other MemberNodes which are users of it. In this sense, the graph can navigated bi-directionally across the use relationship between MemberNodes.

    Great effort is taken to keep the bookkeeping of the UsageGraph as tight as possible, so that rather large code bases can be analyzed. While nodes can grant access to the underlying Java Reflection APIs (e.g. Class, Constructor, Field, Member), the results are stored using WeakReferences to assist with memory usage.

    A class Filter can be specified to limit the set of classes on which usage references will be tracked. This is often done to limit memory usage to interesting classes. For example, the java.util package is very often used, and tracking usages would require a massive bookkeeping effort which has little value.

    See Also:
    UsageGraphBuilder, ClassNode, MemberNode, ConstructorNode, FieldNode, MethodNode, NodeVisitor, NodeVisitorAcceptor