Class Indexer


  • public final class Indexer
    extends Object
    Analyzes and indexes the annotation and key structural information of a set of classes. The indexer will purposefully skip any class that is not Java 5 or later. It will also do a basic/quick structural scan on any class it determines does not have annotations.

    The Indexer operates on input streams that point to class file data. Input streams do not need to be buffered, as the indexer already does this. There is also no limit to the number of class file streams the indexer can process, other than available memory.

    The Indexer attempts to minimize the final memory state of the index, but to do this it must maintain additional in-process state (intern tables etc) until the index is complete.

    Numerous optimizations are taken during indexing to attempt to minimize the CPU and I/O cost, however, the Java class file format was not designed for partial searching, which ultimately limits the efficiency of processing them.

    Thread-Safety This class is not thread-safe can not be shared between threads. The index it produces however is thread-safe.

    Author:
    Jason T. Greene
    • Constructor Detail

      • Indexer

        public Indexer()
    • Method Detail

      • indexClass

        public ClassInfo indexClass​(Class<?> clazz)
                             throws IOException
        Analyze and index the class file data present in the passed class. Each call adds information to the final complete index; however, to aid in processing a per-class index (ClassInfo) is returned on each call.
        Parameters:
        clazz - a previously-loaded class
        Returns:
        a class index containing all annotations on the passed class stream
        Throws:
        IOException - if the class file data is corrupt or the underlying stream fails
        IllegalArgumentException - if clazz is null
      • index

        public ClassInfo index​(InputStream stream)
                        throws IOException
        Analyze and index the class file data present in the passed input stream. Each call adds information to the final complete index; however, to aid in processing a per-class index (ClassInfo) is returned on each call.
        Parameters:
        stream - a stream pointing to class file data
        Returns:
        a class index containing all annotations on the passed class stream
        Throws:
        IOException - if the class file data is corrupt or the underlying stream fails
        IllegalArgumentException - if stream is null
      • complete

        public Index complete()
        Completes, finalizes, and returns the index after zero or more calls to index. Future calls to index will result in a new index.
        Returns:
        the master index for all scanned class streams