AbstractRetrievalPostProcessor (NASA World Wind)

java.lang.Object
- gov.nasa.worldwind.retrieve.AbstractRetrievalPostProcessor

All Implemented Interfaces:

RetrievalPostProcessor

Direct Known Subclasses:

BasicDataFileStore.PostProcessor, BasicElevationModel.DownloadPostProcessor, BasicTiledImageLayer.DownloadPostProcessor, PlaceNameLayer.DownloadPostProcessor, TiledImageLayer.CompositionRetrievalPostProcessor, WMSBasicElevationModel.CompositionRetrievalPostProcessor
```
public abstract class AbstractRetrievalPostProcessor
extends Object
implements RetrievalPostProcessor
```
Abstract base class for retrieval post-processors. Verifies the retrieval operation and dispatches the content to the a subclasses content handlers.
Subclasses are expected to override the methods necessary to handle their particular post-processing operations.

Field Summary

Fields
Modifier and Type	Field and Description
`protected AVList`	`avList` Holds miscellaneous parameters examined by this and subclasses.
`protected Retriever`	`retriever` The retriever associated with the post-processor.

Constructor Summary

Constructors
Constructor and Description
`AbstractRetrievalPostProcessor()` Create a default post-processor.
`AbstractRetrievalPostProcessor(AVList avList)` Create a post-processor and pass it attributes that can be examined during content handling.

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`protected ByteBuffer`	`convertToDDS()` Converts an image to DDS.
`protected abstract File`	`doGetOutputFile()` Abstract method that subclasses must provide to identify the output file for the post-processor's retrieval content.
`protected Object`	`getFileLock()` Returns an object that can be used to synchronize writing to the output file.
`protected File`	`getOutputFile()` Determines and returns the output file for the retrieved data.
`Retriever`	`getRetriever()` Returns the retriever associarted with this post-processor.
`protected ByteBuffer`	`handleApplicationContent()` Handles application content.
`protected ByteBuffer`	`handleContent()` Process the retrieved data.
`protected void`	`handleContentException(Exception e)` Reacts to exceptions occurring during content handling.
`protected ByteBuffer`	`handleHTMLContent()` Handles HTML content.
`protected ByteBuffer`	`handleImageContent()` Handles image content.
`protected void`	`handleInvalidResponseCode()` Handle the case of an invalid response code.
`protected ByteBuffer`	`handleSuccessfulRetrieval()` Process the retrieved data if it has been retrieved successfully.
`protected ByteBuffer`	`handleTextContent()` Handles Text content.
`protected ByteBuffer`	`handleUnknownContentType()` Handles content types that are not recognized by the content handler.
`protected void`	`handleUnsuccessfulRetrieval()` Called when the retrieval state is other than `Retriever.RETRIEVER_STATE_SUCCESSFUL`.
`protected ByteBuffer`	`handleWMSExceptionContent()` Handles WMS exceptions.
`protected ByteBuffer`	`handleXMLContent()` Handles XML content.
`protected ByteBuffer`	`handleZipContent()` Handles zipped content.
`protected boolean`	`isDeleteOnExit(File outFile)` Indicates whether the output file should have its delete-on-exit flag set so that it's deleted when the JVM terminates.
`protected boolean`	`isPrimaryContentType(String typeOfContent, String contentType)`
`protected boolean`	`isWMSException()`
`protected void`	`logTextBuffer(ByteBuffer buffer)` Log the content of a buffer as a String.
`protected void`	`markResourceAbsent()` Marks the retrieval target absent.
`protected boolean`	`overwriteExistingFile()` Indicates whether the retrieved data should be written to the output file if a file of the same name already exists.
`ByteBuffer`	`run(Retriever retriever)` Runs the post-processor.
`protected boolean`	`saveBuffer()` Saves the retrieved and possibly transformed data.
`protected boolean`	`saveBuffer(ByteBuffer buffer)` Saves the retrieved and possibly transformed data.
`protected ByteBuffer`	`saveDDS()` Saves a DDS image file after first converting any other image format to DDS.
`protected BufferedImage`	`transformPixels()` Transform the retrieved data in some purpose-specific way.
`protected boolean`	`validateHTTPResponseCode()` Checks the retrieval's HTTP response code.
`protected boolean`	`validateJarResponseCode()` Checks the retrieval's HTTP response code.
`protected boolean`	`validateResponseCode()` Checks the retrieval response code.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - avList
```
protected AVList avList
```
    Holds miscellaneous parameters examined by this and subclasses.
  - retriever
```
protected Retriever retriever
```
    The retriever associated with the post-processor. Only non-null after run(Retriever) is called.
- Constructor Detail
  - AbstractRetrievalPostProcessor
```
public AbstractRetrievalPostProcessor()
```
    Create a default post-processor.
  - AbstractRetrievalPostProcessor
```
public AbstractRetrievalPostProcessor(AVList avList)
```
    Create a post-processor and pass it attributes that can be examined during content handling.
    
    Parameters:
    
    avList - an attribute-value list with values that might be used during post-processing.
- Method Detail
  - convertToDDS
```
protected ByteBuffer convertToDDS()
                           throws IOException
```
    Converts an image to DDS. If the image format is not originally DDS, calls transformPixels() to perform any defined image transform.
    
    Returns:
    
    the converted image data if a conversion is performed, otherwise the original image data.
    
    Throws:
    
    IOException - if an IO error occurs while converting the image.
  - doGetOutputFile
```
protected abstract File doGetOutputFile()
```
    Abstract method that subclasses must provide to identify the output file for the post-processor's retrieval content.
    
    Returns:
    
    the output file.
  - getFileLock
```
protected Object getFileLock()
```
    Returns an object that can be used to synchronize writing to the output file. Superclasses should override this method and return the object used as a lock by other objects that read or otherwise interact with the output file.
    
    Returns:
    
    an object to use for read/write synchronization, or null if no lock is needed.
  - getOutputFile
```
protected File getOutputFile()
```
    Determines and returns the output file for the retrieved data.
    
    Returns:
    
    the output file, or null if a file could not be determined.
  - getRetriever
```
public Retriever getRetriever()
```
    Returns the retriever associarted with this post-processor.
    
    Returns:
    
    the retriever associated with the post-processor, or null if no retriever is associated.
  - handleApplicationContent
```
protected ByteBuffer handleApplicationContent()
                                       throws IOException
```
    Handles application content. The default implementation saves the retrieved data without modification via saveBuffer() without.
    
    Returns:
    
    a buffer containing the retrieved data.
    
    Throws:
    
    IOException - if an IO error occurs while processing the data.
  - handleContent
```
protected ByteBuffer handleContent()
                            throws IOException
```
    Process the retrieved data. Dispatches content handling to content-type specific handlers: handleZipContent() for content types containing "zip", handleTextContent() for content types starting with "text", and handleImageContent() for contents types starting with "image".
    
    Returns:
    
    a buffer containing the retrieved data, which may have been transformed during content handling.
    
    Throws:
    
    IOException - if an IO error occurs while processing the data.
  - handleContentException
```
protected void handleContentException(Exception e)
```
    Reacts to exceptions occurring during content handling. Subclasses may override this method to perform special exception handling. The default implementation logs a message specific to the exception.
    
    Parameters:
    
    e - the exception to handle.
  - handleHTMLContent
```
protected ByteBuffer handleHTMLContent()
                                throws IOException
```
    Handles HTML content. The default implementation only calls logTextBuffer(java.nio.ByteBuffer) and returns.
    
    Returns:
    
    a buffer containing the retrieved HTML.
    
    Throws:
    
    IOException - if an IO error occurs while processing the data.
  - handleImageContent
```
protected ByteBuffer handleImageContent()
                                 throws IOException
```
    Handles image content. The default implementation simply saves the retrieved data via saveBuffer(), first converting it to DDS if the suffix of the output file is .dds.
    The default implementation of this method returns immediately if the output file cannot be determined or it exists and overwriteExistingFile() returns false.
    
    Returns:
    
    a buffer containing the retrieved data.
    
    Throws:
    
    IOException - if an IO error occurs while processing the data.
  - handleInvalidResponseCode
```
protected void handleInvalidResponseCode()
```
    Handle the case of an invalid response code. Subclasses can override this method to handle special cases. The default implementation calls markResourceAbsent() and logs the contents of the retrieval buffer if it contains content of type "text".
  - handleSuccessfulRetrieval
```
protected ByteBuffer handleSuccessfulRetrieval()
```
    Process the retrieved data if it has been retrieved successfully.
    
    Returns:
    
    a buffer containing the downloaded data, perhaps converted during content handling.
  - handleTextContent
```
protected ByteBuffer handleTextContent()
                                throws IOException
```
    Handles Text content. If the content type is text/xml, handleXMLContent() is called. If the content type is text/html, handleHTMLContent() is called. For all other sub-types the content is logged as a message with level Level.SEVERE.
    
    Returns:
    
    a buffer containing the retrieved text.
    
    Throws:
    
    IOException - if an IO error occurs while processing the data.
  - handleUnknownContentType
```
protected ByteBuffer handleUnknownContentType()
```
    Handles content types that are not recognized by the content handler. Subclasses may override this method to handle such cases. The default implementation logs an error message and returns null.
    
    Returns:
    
    null if no further processing should occur, otherwise the retrieved data, perhaps transformed.
  - handleUnsuccessfulRetrieval
```
protected void handleUnsuccessfulRetrieval()
```
    Called when the retrieval state is other than Retriever.RETRIEVER_STATE_SUCCESSFUL. Can be overridden by subclasses to handle special error cases. The default implementation calls markResourceAbsent() if the retrieval state is Retriever.RETRIEVER_STATE_ERROR.
  - handleWMSExceptionContent
```
protected ByteBuffer handleWMSExceptionContent()
```
    Handles WMS exceptions.
    
    Returns:
    
    a buffer containing the retrieved XML.
  - handleXMLContent
```
protected ByteBuffer handleXMLContent()
                               throws IOException
```
    Handles XML content. The default implementation only calls logTextBuffer(java.nio.ByteBuffer) and returns.
    
    Returns:
    
    a buffer containing the retrieved XML.
    
    Throws:
    
    IOException - if an IO error occurs while processing the data.
  - handleZipContent
```
protected ByteBuffer handleZipContent()
                               throws IOException
```
    Handles zipped content. The default implementation saves the data to the retriever's output file without unzipping it.
    
    Returns:
    
    a buffer containing the retrieved data.
    
    Throws:
    
    IOException - if an IO error occurs while processing the data.
  - isDeleteOnExit
```
protected boolean isDeleteOnExit(File outFile)
```
    Indicates whether the output file should have its delete-on-exit flag set so that it's deleted when the JVM terminates.
    
    Parameters:
    
    outFile - the output file.
    
    Returns:
    
    true if the output file's delete-on-exit flag should be set, otherwise false.
  - isPrimaryContentType
```
protected boolean isPrimaryContentType(String typeOfContent,
                                       String contentType)
```
  - isWMSException
```
protected boolean isWMSException()
```
  - logTextBuffer
```
protected void logTextBuffer(ByteBuffer buffer)
```
    Log the content of a buffer as a String. If the buffer is null or empty, nothing is logged. Only the first 2,048 characters of the buffer are included in the log message.
    
    Parameters:
    
    buffer - the content to log. The content is assumed to be of type "text".
  - markResourceAbsent
```
protected void markResourceAbsent()
```
    Marks the retrieval target absent. Subclasses should override this method if they keep track of absent-resources. The default implementation does nothing.
  - overwriteExistingFile
```
protected boolean overwriteExistingFile()
```
    Indicates whether the retrieved data should be written to the output file if a file of the same name already exists. The default implementation of this method returns false (files are not overwritten).
    
    Returns:
    
    true if an existing file should be overwritten, otherwise false.
  - run
```
public ByteBuffer run(Retriever retriever)
```
    Runs the post-processor.
    
    Specified by:
    
    run in interface RetrievalPostProcessor
    
    Parameters:
    
    retriever - the retriever to associate with the post-processor.
    
    Returns:
    
    a buffer containing the downloaded data, perhaps converted during content handling. null is returned if a fatal problem occurred during post-processing.
    
    Throws:
    
    IllegalArgumentException - if the retriever is null.
  - saveBuffer
```
protected boolean saveBuffer()
                      throws IOException
```
    Saves the retrieved and possibly transformed data. The data may have been transformed during content handling.
    The default implementation of this method simply calls saveBuffer(java.nio.ByteBuffer) with an argument of null.
    
    Returns:
    
    true if the buffer was saved, false if the output file could not be determined or already exists and not overwritten.
    
    Throws:
    
    IOException - if an IO error occurs while attempting to save the buffer.
  - saveBuffer
```
protected boolean saveBuffer(ByteBuffer buffer)
                      throws IOException
```
    Saves the retrieved and possibly transformed data. The data may have been transformed during content handling. The data is not saved if the output file already exists unless overwriteExistingFile() returns true.
    
    Parameters:
    
    buffer - the buffer to save.
    
    Returns:
    
    true if the buffer was saved, false if the output file could not be determined or already exists and not overwritten.
    
    Throws:
    
    IOException - if an IO error occurred when attempting to save the buffer.
  - saveDDS
```
protected ByteBuffer saveDDS()
                      throws IOException
```
    Saves a DDS image file after first converting any other image format to DDS.
    
    Returns:
    
    the converted image data if a conversion is performed, otherwise the original image data.
    
    Throws:
    
    IOException - if an IO error occurs while converting or saving the image.
  - transformPixels
```
protected BufferedImage transformPixels()
```
    Transform the retrieved data in some purpose-specific way. May be overridden by subclasses to perform special transformations. The default implementation calls ImageUtil.mapTransparencyColors(java.awt.image.BufferedImage, int[]) if the attribute-value list specified at construction contains transparency colors (includes the AVKey.TRANSPARENCY_COLORS key).
    
    Returns:
    
    returns the transformed data if a transform is performed, otherwise returns the original data.
  - validateHTTPResponseCode
```
protected boolean validateHTTPResponseCode()
```
    Checks the retrieval's HTTP response code. Must only be called when the retriever is a subclass of HTTPRetriever.
    
    Returns:
    
    true if the response code is HttpURLConnection.HTTP_OK, otherwise false.
  - validateJarResponseCode
```
protected boolean validateJarResponseCode()
```
    Checks the retrieval's HTTP response code. Must only be called when the retriever is a subclass of HTTPRetriever.
    
    Returns:
    
    true if the response code is HttpURLConnection.HTTP_OK, otherwise false.
  - validateResponseCode
```
protected boolean validateResponseCode()
```
    Checks the retrieval response code.
    
    Returns:
    
    true if the response code is the OK value for the protocol, e.g., (HttpURLConnection.HTTP_OK for HTTP protocol), otherwise false.

Class AbstractRetrievalPostProcessor

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

avList

retriever

Constructor Detail

AbstractRetrievalPostProcessor

AbstractRetrievalPostProcessor

Method Detail

convertToDDS

doGetOutputFile

getFileLock

getOutputFile

getRetriever

handleApplicationContent

handleContent

handleContentException

handleHTMLContent

handleImageContent

handleInvalidResponseCode

handleSuccessfulRetrieval

handleTextContent

handleUnknownContentType

handleUnsuccessfulRetrieval

handleWMSExceptionContent

handleXMLContent

handleZipContent

isDeleteOnExit

isPrimaryContentType

isWMSException

logTextBuffer

markResourceAbsent

overwriteExistingFile

run

saveBuffer

saveBuffer

saveDDS

transformPixels

validateHTTPResponseCode

validateJarResponseCode

validateResponseCode