Package org.esa.snap.core.dataio

Class AbstractProductReader

java.lang.Object
org.esa.snap.core.dataio.AbstractProductReader
All Implemented Interfaces:
ProductReader
Direct Known Subclasses:
AbstractProductBuilder, DimapProductReader, ImageProductReader
public abstract class AbstractProductReader extends Object implements ProductReader
The AbstractProductReader class can be used as a base class for new product reader implementations. The only two methods which clients must implement are readProductNodes(Object, ProductSubsetDef) and readBandRasterData(Band, int, int, int, int, ProductData, ProgressMonitor) methods.

To simplify implementation it is encouraged to implement readProductNodesImpl() and readBandRasterDataImpl(...) instead.

Version:
$Revision$ $Date$
See Also:

  • Field Details

    • input

      protected Object input
      The input source

  • Constructor Details

    • AbstractProductReader

      protected AbstractProductReader(ProductReaderPlugIn readerPlugIn)
      Constructs a new abstract product reader.
      Parameters:
      readerPlugIn - the reader plug-in which created this reader, can be null for internal reader implementations

  • Method Details

    • getReaderPlugIn

      public ProductReaderPlugIn getReaderPlugIn()
      Returns the plug-in which created this product reader.
      Specified by:
      getReaderPlugIn in interface ProductReader
      Returns:
      the product reader plug-in, should never be null

    • getInput

      public Object getInput()
      Retrives the current output destination object. The return value might be null if the setInput() method has not been called so far.
      Specified by:
      getInput in interface ProductReader

    • setInput

      protected void setInput(Object input)

    • isMetadataIgnored

      public boolean isMetadataIgnored()
      Checks if this reader ignores metadata or not.
      Returns:
      true if so

    • getSubsetDef

      public ProductSubsetDef getSubsetDef()
      Returns the subset information with which this data product is read from its physical source.
      Specified by:
      getSubsetDef in interface ProductReader
      Returns:
      the subset information, can be null

    • setSubsetDef

      protected void setSubsetDef(ProductSubsetDef subsetDef)
      Sets the subset information.
      Parameters:
      subsetDef - the subset definition

    • isNodeAccepted

      public boolean isNodeAccepted(String name)
      Tests whether or not a product node (a band, a tie-point grid or metadata element) with the given name is accepted with respect to the optional spectral band subset. All accepted nodes will be part of the product read.
      Parameters:
      name - the node name
      Returns:
      true if so

    • readProductNodes

      public Product readProductNodes(Object input, ProductSubsetDef subsetDef) throws IOException
      Reads the nodes of a data product and returns an in-memory representation of it.

      The given subset info can be used to specify spatial and spectral portions of the original product. If the subset is omitted, the complete product is read in.

      Whether the band data - the actual pixel values - is read in immediately or later when pixels are requested, is up to the implementation.

      Specified by:
      readProductNodes in interface ProductReader
      Parameters:
      input - an object representing a valid output for this product reader, might be a ImageInputStream or other Object to use for future decoding.
      subsetDef - a spectral or spatial subset (or both) of the product. If null, the entire product is read in
      Throws:
      IllegalArgumentException - if input type is not supported (see ProductReaderPlugIn.getInputTypes()).
      IOException - if an I/O error occurs
      IllegalFileFormatException - if the file format is unknown.

    • readProductNodesImpl

      protected abstract Product readProductNodesImpl() throws IOException
      Provides an implementation of the readProductNodes interface method. Clients implementing this method can be sure that the input object and eventually the subset information has already been set.

      This method is called as a last step in the readProductNodes(input, subsetInfo) method.

      Returns:
      a new product instance
      Throws:
      IOException - if an I/O error occurs

    • readGeoCoding

      public GeoCoding readGeoCoding(Product product) throws IOException
      Specified by:
      readGeoCoding in interface ProductReader
      Returns:
      Throws:
      IOException

    • readBandRasterData

      public void readBandRasterData(Band destBand, int destOffsetX, int destOffsetY, int destWidth, int destHeight, ProductData destBuffer, ProgressMonitor pm) throws IOException
      Reads raster data from the data source specified by the given destination band into the given in-memory buffer and region.

      For a complete description, please refer to the ProductReader.readBandRasterData(Band, int, int, int, int, ProductData, com.bc.ceres.core.ProgressMonitor) interface definition} of this method.

      The AbstractProductReader implements this method using the Template Method pattern. The template method in this case is the abstract method to which the call is delegated after an optional spatial subset given by getSubsetDef() has been applied to the input parameters.

      Specified by:
      readBandRasterData in interface ProductReader
      Parameters:
      destBand - the destination band which identifies the data source from which to read the sample values
      destOffsetX - the X-offset in the band's raster co-ordinates
      destOffsetY - the Y-offset in the band's raster co-ordinates
      destWidth - the width of region to be read given in the band's raster co-ordinates
      destHeight - the height of region to be read given in the band's raster co-ordinates
      destBuffer - the destination buffer which receives the sample values to be read
      pm - a monitor to inform the user about progress
      Throws:
      IOException - if an I/O error occurs
      IllegalArgumentException - if the number of elements destination buffer not equals destWidth * destHeight or the destination region is out of the band's raster
      See Also:

    • isSubsetReadingFullySupported

      public boolean isSubsetReadingFullySupported()
      Returns if the reader fully supports the reading of subsets. Including sub-sampling in X- and Y-direction. This method is intended to be a hint to the SNAP framework. Depending on the return value the reading can be optimised.

      Implementations of this class should override this method in order to specify if subset reading is fully supported. The default implementation returns false

      Returns:
      false or true, depending if subset reading is fully supported or not.

    • readBandRasterDataImpl

      protected abstract void readBandRasterDataImpl(int sourceOffsetX, int sourceOffsetY, int sourceWidth, int sourceHeight, int sourceStepX, int sourceStepY, Band destBand, int destOffsetX, int destOffsetY, int destWidth, int destHeight, ProductData destBuffer, ProgressMonitor pm) throws IOException
      The template method which is called by the method after an optional spatial subset has been applied to the input parameters.

      The destination band, buffer and region parameters are exactly the ones passed to the original call. Since the destOffsetX and destOffsetY parameters are already taken into account in the sourceOffsetX and sourceOffsetY parameters, an implementor of this method is free to ignore them.

      Parameters:
      sourceOffsetX - the absolute X-offset in source raster co-ordinates
      sourceOffsetY - the absolute Y-offset in source raster co-ordinates
      sourceWidth - the width of region providing samples to be read given in source raster co-ordinates
      sourceHeight - the height of region providing samples to be read given in source raster co-ordinates
      sourceStepX - the sub-sampling in X direction within the region providing samples to be read
      sourceStepY - the sub-sampling in Y direction within the region providing samples to be read
      destBand - the destination band which identifies the data source from which to read the sample values
      destOffsetX - the X-offset in the band's raster co-ordinates
      destOffsetY - the Y-offset in the band's raster co-ordinates
      destWidth - the width of region to be read given in the band's raster co-ordinates
      destHeight - the height of region to be read given in the band's raster co-ordinates
      destBuffer - the destination buffer which receives the sample values to be read
      pm - a monitor to inform the user about progress
      Throws:
      IOException - if an I/O error occurs
      See Also:

    • close

      public void close() throws IOException
      Closes the access to all currently opened resources such as file input streams and all resources of this children directly owned by this reader. Its primary use is to allow the garbage collector to perform a vanilla job.

      This method should be called only if it is for sure that this object instance will never be used again. The results of referencing an instance of this class after a call to close() are undefined.

      Overrides of this method should always call super.close(); after disposing this instance.

      Specified by:
      close in interface ProductReader
      Throws:
      IOException - if an I/O error occurs

    • getProductComponents

      public TreeNode<File> getProductComponents()
      Retrieves a set of TreeNode objects that represent the physical product structure as stored on the harddrive. The tree consists of: - a root node (the one returned) pointing to the directory that CONTAINS the product - any number of nested children that compose the product. Each TreeNod is configured as follows: - id: contains a string representation of the path. For the root node, this is the absolute path to the parent of the file returned by Product.getFileLocation(). For all subsequent nodes, the node name. - content: each node stores as content a java.io.File object that physically defines the node.

      The method returns null when a TreeNode can not be assembled (i.e. in-memory product, created from stream ...)

      Returns:
      the root TreeNode or null

    • isInstanceOfValidInputType

      protected boolean isInstanceOfValidInputType(Object input)
      Checks if the given object is an instance of one of the valid input types for this product reader.
      Parameters:
      input - the input object passed to readProductNodes(Object, ProductSubsetDef)
      Returns:
      true if so
      See Also:

    • getGridDiscontinutity

      protected int getGridDiscontinutity(String name)
      Used by the createTiePointGrid method in order to determine the discontinuity mode for angle tie-point grids.

      The default implementation returns TiePointGrid.DISCONT_AT_180 for the names "lon", "long" or "longitude" ignoring letter case, TiePointGrid.DISCONT_NONE otherwise.

      Parameters:
      name - the grid name
      Returns:
      the discontinuity mode, always one of TiePointGrid.DISCONT_NONE, TiePointGrid.DISCONT_AT_180 and TiePointGrid.DISCONT_AT_360.

    • createTiePointGrid

      protected TiePointGrid createTiePointGrid(String gridName, int gridWidth, int gridHeight, double offsetX, double offsetY, double subSamplingX, double subSamplingY, float[] tiePoints)
      Creates a tie point grid from the given properties.

      The method uses the getGridDiscontinutity(String) method in order to create an appropriate angular tie-point grids.

      Parameters:
      gridName - the grid name
      gridWidth - the grid's raster width
      gridHeight - the grid's raster height
      offsetX - the grid origin's X-coordinate in pixel units
      offsetY - the grid origin's Y-coordinate in pixel units
      subSamplingX - the grid X-subsampling in pixel units
      subSamplingY - the grid Y-subsampling in pixel units
      tiePoints - the tie-points
      Returns:
      the tie-point grid instance, never null

    • buildTiePointGrid

      protected static TiePointGrid buildTiePointGrid(String gridName, int gridWidth, int gridHeight, double offsetX, double offsetY, double subSamplingX, double subSamplingY, float[] tiePoints)

    • buildTiePointGrid

      protected static TiePointGrid buildTiePointGrid(String gridName, int gridWidth, int gridHeight, double offsetX, double offsetY, double subSamplingX, double subSamplingY, float[] tiePoints, int gridDiscontinutity)

    • configurePreferredTileSize

      public static void configurePreferredTileSize(Product product)

    • toString

      public String toString()
      Returns a string representation of the reader.
      Overrides:
      toString in class Object
      Returns:
      a string representation of the object.

    • convertInputToPath

      public static Path convertInputToPath(Object input)