Class IndexReader

java.lang.Object
org.jboss.jandex.IndexReader

public final class IndexReader extends Object
Reads a Jandex index file and returns the saved index. See Indexer for a thorough description of how the Index data is produced.

An IndexReader loads the stream passed to it's constructor and applies the appropriate buffering. The Jandex index format is designed for efficient reading and low final memory storage.

Thread-Safety

IndexReader is not thread-safe and can not be shared between concurrent threads. The resulting index, however, is.
  • Field Details

  • Constructor Details

    • IndexReader

      public IndexReader(InputStream input)
      Constructs a new IndedReader using the passed stream. The stream is not read from until the read method is called.
      Parameters:
      input - a stream which points to a jandex index file
  • Method Details

    • read

      public Index read() throws IOException
      Read the index at the associated stream of this reader. This method can be called multiple times if the stream contains multiple index files.
      Returns:
      the Index contained in the stream
      Throws:
      IOException - if an I/O error occurs
      IllegalArgumentException - if the stream does not point to Jandex index data
      UnsupportedVersion - if the index data is tagged with a version not known to this reader
    • initReader

      private void initReader(int version) throws IOException
      Throws:
      IOException
    • getDataVersion

      public int getDataVersion() throws IOException
      Returns the version of the data contract stored in the index that was read. This version is incremented when the contract adds new information. Generally this is used to determine if the underlying index contains necessary information for analysis. As an example, generics are recorded in version 4; therefore, a tool that requires generic data would need to reject/ignore version 3 data.
      The data contract version should not be confused with the index file version, which represents the internal storage format of the file. The index file version moves independently of the data contract.
      Returns:
      The data contract version of the index that was read
      Throws:
      IOException - If the index could not be read
    • getIndexVersion

      public int getIndexVersion() throws IOException
      Returns the index file version. Note that the index file version may increment even though the underlying data contract remains the same. In most cases, getDataVersion() should be used instead of this method, since applications are typically interested in the underlying contract of the data stored, and not the internal implementation details of a Jandex index.
      Returns:
      the internal index file version
      Throws:
      IOException - If the index could not be read
    • readVersion

      private void readVersion() throws IOException
      Throws:
      IOException