Package uk.ac.starlink.datanode.nodes

Class ZipArchiveDataNode

java.lang.Object
uk.ac.starlink.datanode.nodes.DefaultDataNode
uk.ac.starlink.datanode.nodes.ZipArchiveDataNode
All Implemented Interfaces:
DataNode
Direct Known Subclasses:
ZipFileDataNode, ZipStreamDataNode
public abstract class ZipArchiveDataNode extends DefaultDataNode
DataNode representing a Zip archive. This abstract class embodies the common functionality required by its subclasses ZipFileDataNode and ZipStreamDataNode.
Author:
Mark Taylor (Starlink)

  • Constructor Details

    • ZipArchiveDataNode

      protected ZipArchiveDataNode(uk.ac.starlink.util.DataSource datsrc) throws NoSuchDataException
      Constructs a ZipArchiveDataNode.
      Parameters:
      datsrc - a data source corresponding to the archive; this is used for checking the magic number to see whether it looks like a zip archive or not
      Throws:
      NoSuchDataException

  • Method Details

    • getEntries

      protected abstract List getEntries() throws IOException
      Returns a list of all the ZipEntry objects in this zip archive.
      Returns:
      a List of all the ZipEntry objects which make up this zip archive.
      Throws:
      IOException

    • getChildIteratorAtLevel

      protected abstract Iterator getChildIteratorAtLevel(String level, DataNode parent) throws IOException
      Returns an iterator over the DataNodes at a given level in the hierarchy of this archive. The iterator creates DataNodes for each ZipEntry in this archive whose name begins with the supplied string level.
      Parameters:
      level - the required starting substring of the name of all ZipEntries to be represented in the result
      parent - the DataNode whose children the resulting nodes will be
      Returns:
      an Iterator over DataNode objects corresponding to the ZipEntry objects specified by level
      Throws:
      IOException

    • isMagic

      public static boolean isMagic(byte[] magic)
      Tests whether the presented byte array looks like the start of a Zip archive.
      Parameters:
      magic - a byte array containing the first few bytes of a source which might be a zip
      Returns:
      true iff magic represents the magic number of a zip archive

    • getName

      public String getName()
      Description copied from interface: DataNode
      Gets the name of this object. This is an intrinsic property of the object.
      Specified by:
      getName in interface DataNode
      Overrides:
      getName in class DefaultDataNode
      Returns:
      the name of the object

    • getPathSeparator

      public String getPathSeparator()
      Description copied from class: DefaultDataNode
      Returns a default separator string.
      Specified by:
      getPathSeparator in interface DataNode
      Overrides:
      getPathSeparator in class DefaultDataNode
      Returns:
      "."

    • getNodeTLA

      public String getNodeTLA()
      Returns the string "ZIP".
      Specified by:
      getNodeTLA in interface DataNode
      Overrides:
      getNodeTLA in class DefaultDataNode
      Returns:
      "ZIP"

    • getNodeType

      public String getNodeType()
      Description copied from interface: DataNode
      Returns a short sentence indicating what kind of node this is. The return value should be just a few words. As a rough guideline it should indicate what the implementing class is.
      Specified by:
      getNodeType in interface DataNode
      Overrides:
      getNodeType in class DefaultDataNode
      Returns:
      a short description of the type of this DataNode

    • allowsChildren

      public boolean allowsChildren()
      Description copied from class: DefaultDataNode
      The DefaultDataNode implementation of this method returns false.
      Specified by:
      allowsChildren in interface DataNode
      Overrides:
      allowsChildren in class DefaultDataNode
      Returns:
      true if the node is of a type which can have child nodes, false otherwise

    • getChildIterator

      public Iterator getChildIterator()
      Description copied from class: DefaultDataNode
      The DefaultDataNode implementation of this method throws UnsupportedOperationException (DefaultDataNode.allowsChildren() is false).
      Specified by:
      getChildIterator in interface DataNode
      Overrides:
      getChildIterator in class DefaultDataNode
      Returns:
      an Iterator over the children. Each object iterated over should be a DataNode. Behaviour is undefined if this method is called on an object for which allowsChildren returns false.

    • getEntriesAtLevel

      protected List getEntriesAtLevel(String level) throws IOException
      Returns all the ZipEntry objects in this archive at a given level in the hierarchy. The selected entries are all those whose name starts with the supplied string level.
      Parameters:
      level - the required starting substring of the name of all ZipEntries to be returned
      Returns:
      a list of all the ZipEntry objects at the given level
      Throws:
      IOException