Package org.geotools.data.shapefile.files

Class ShpFiles

Object
ShpFiles
public class ShpFiles extends Object
The collection of all the files that are the shapefile and its metadata and indices.

This class has methods for performing actions on the files. Currently mainly for obtaining read and write channels and streams. But in the future a move method may be introduced.

Note: The method that require locks (such as getInputStream()) will automatically acquire locks and the javadocs should document how to release the lock. Therefore the methods acquireRead(ShpFileType, FileReader) and acquireWrite(ShpFileType, FileWriter) svn

Author:
jesse

  • Field Details

  • Constructor Details

  • Method Details

    • finalize

      protected void finalize() throws Throwable
      This verifies that this class has been closed correctly (nothing locking)
      Overrides:
      finalize in class Object
      Throws:
      Throwable

    • dispose

      public void dispose()

    • logCurrentLockers

      public void logCurrentLockers(Level logLevel)
      Writes to the log all the lockers and when they were constructed.
      Parameters:
      logLevel - the level at which to log.

    • getFileNames

      public Map<ShpFileType,String> getFileNames()
      Returns the URLs (in string form) of all the files for the shapefile datastore.
      Returns:
      the URLs (in string form) of all the files for the shapefile datastore.

    • get

      public String get(ShpFileType type)
      Returns the string form of the url that identifies the file indicated by the type parameter or null if it is known that the file does not exist.

      Note: a URL should NOT be constructed from the string instead the URL should be obtained through calling one of the aquireLock methods.

      Parameters:
      type - indicates the type of file the caller is interested in.
      Returns:
      the string form of the url that identifies the file indicated by the type parameter or null if it is known that the file does not exist.

    • numberOfLocks

      public int numberOfLocks()
      Returns the number of locks on the current set of shapefile files. This is not thread safe so do not count on it to have a completely accurate picture but it can be useful debugging
      Returns:
      the number of locks on the current set of shapefile files.

    • acquireReadFile

      public File acquireReadFile(ShpFileType type, FileReader requestor)
      Acquire a File for read only purposes. It is recommended that get*Stream or get*Channel methods are used when reading or writing to the file is desired.
      Parameters:
      type - the type of the file desired.
      requestor - the object that is requesting the File. The same object must release the lock and is also used for debugging.
      Returns:
      the File type requested
      See Also:

    • acquireRead

      public URL acquireRead(ShpFileType type, FileReader requestor)
      Acquire a URL for read only purposes. It is recommended that get*Stream or get*Channel methods are used when reading or writing to the file is desired.
      Parameters:
      type - the type of the file desired.
      requestor - the object that is requesting the URL. The same object must release the lock and is also used for debugging.
      Returns:
      the URL to the file of the type requested
      See Also:

    • tryAcquireRead

      public Result<URL,ShpFiles.State> tryAcquireRead(ShpFileType type, FileReader requestor)
      Tries to acquire a URL for read only purposes. Returns null if the acquire failed or if the file does not.

      It is recommended that get*Stream or get*Channel methods are used when reading or writing to the file is desired.

      Parameters:
      type - the type of the file desired.
      requestor - the object that is requesting the URL. The same object must release the lock and is also used for debugging.
      Returns:
      A result object containing the URL or the reason for the failure.
      See Also:

    • unlockRead

      public void unlockRead(File file, FileReader requestor)
      Unlocks a read lock. The file and requestor must be the the same as the one of the lockers.
      Parameters:
      file - file that was locked
      requestor - the class that requested the file

    • unlockRead

      public void unlockRead(URL url, FileReader requestor)
      Unlocks a read lock. The url and requestor must be the the same as the one of the lockers.
      Parameters:
      url - url that was locked
      requestor - the class that requested the url

    • acquireWriteFile

      public File acquireWriteFile(ShpFileType type, FileWriter requestor)
      Acquire a File for read and write purposes.

      It is recommended that get*Stream or get*Channel methods are used when reading or writing to the file is desired.

      Parameters:
      type - the type of the file desired.
      requestor - the object that is requesting the File. The same object must release the lock and is also used for debugging.
      Returns:
      the File to the file of the type requested
      See Also:

    • acquireWrite

      public URL acquireWrite(ShpFileType type, FileWriter requestor)
      Acquire a URL for read and write purposes.

      It is recommended that get*Stream or get*Channel methods are used when reading or writing to the file is desired.

      Parameters:
      type - the type of the file desired.
      requestor - the object that is requesting the URL. The same object must release the lock and is also used for debugging.
      Returns:
      the URL to the file of the type requested
      See Also:

    • tryAcquireWrite

      public Result<URL,ShpFiles.State> tryAcquireWrite(ShpFileType type, FileWriter requestor)
      Tries to acquire a URL for read/write purposes. Returns null if the acquire failed or if the file does not exist

      It is recommended that get*Stream or get*Channel methods are used when reading or writing to the file is desired.

      Parameters:
      type - the type of the file desired.
      requestor - the object that is requesting the URL. The same object must release the lock and is also used for debugging.
      Returns:
      A result object containing the URL or the reason for the failure.
      See Also:

    • unlockWrite

      public void unlockWrite(File file, FileWriter requestor)
      Unlocks a write lock. The file and requestor must be the the same as the one of the lockers.
      Parameters:
      file - file that was locked
      requestor - the class that requested the file

    • unlockWrite

      public void unlockWrite(URL url, FileWriter requestor)
      Unlocks a write lock. The requestor must be have previously obtained a lock for the url.
      Parameters:
      url - url that was locked
      requestor - the class that requested the url

    • isLocal

      public boolean isLocal()
      Determine if the location of this shapefile is local or remote.
      Returns:
      true if local, false if remote

    • isGz

      public boolean isGz()
      Returns:
      whether the files are gzip-ped.

    • isWritable

      public boolean isWritable()
      Returns true if the files are writable

    • delete

      public boolean delete()
      Delete all the shapefile files. If the files are not local or the one files cannot be deleted return false.

    • getInputStream

      public InputStream getInputStream(ShpFileType type, FileReader requestor) throws IOException
      Opens a input stream for the indicated file. A read lock is requested at the method call and released on close.
      Parameters:
      type - the type of file to open the stream to.
      requestor - the object requesting the stream
      Returns:
      an input stream
      Throws:
      IOException - if a problem occurred opening the stream.

    • getOutputStream

      public OutputStream getOutputStream(ShpFileType type, FileWriter requestor) throws IOException
      Opens a output stream for the indicated file. A write lock is requested at the method call and released on close.
      Parameters:
      type - the type of file to open the stream to.
      requestor - the object requesting the stream
      Returns:
      an output stream
      Throws:
      IOException - if a problem occurred opening the stream.

    • getReadChannel

      public ReadableByteChannel getReadChannel(ShpFileType type, FileReader requestor) throws IOException
      Obtain a ReadableByteChannel from the given URL. If the url protocol is file, a FileChannel will be returned. Otherwise a generic channel will be obtained from the urls input stream.

      A read lock is obtained when this method is called and released when the channel is closed.

      Parameters:
      type - the type of file to open the channel to.
      requestor - the object requesting the channel
      Throws:
      IOException

    • getWriteChannel

      public WritableByteChannel getWriteChannel(ShpFileType type, FileWriter requestor) throws IOException
      Obtain a WritableByteChannel from the given URL. If the url protocol is file, a FileChannel will be returned. Currently, this method will return a generic channel for remote urls, however both shape and dbf writing can only occur with a local FileChannel channel.

      A write lock is obtained when this method is called and released when the channel is closed.

      Parameters:
      type - the type of file to open the stream to.
      requestor - the object requesting the stream
      Returns:
      a WritableByteChannel for the provided file type
      Throws:
      IOException - if there is an error opening the stream

    • getStorageFile

      public StorageFile getStorageFile(ShpFileType type) throws IOException
      Obtains a Storage file for the type indicated. An id is provided so that the same file can be obtained at a later time with just the id
      Parameters:
      type - the type of file to create and return
      Returns:
      StorageFile
      Throws:
      IOException - if temporary files cannot be created

    • getTypeName

      public String getTypeName()

    • isMemoryMapCacheEnabled

      public boolean isMemoryMapCacheEnabled()
      Returns the status of the memory map cache. When enabled the memory mapped portions of the files are cached and shared (giving each thread a clone of it)

    • setMemoryMapCacheEnabled

      public void setMemoryMapCacheEnabled(boolean memoryMapCacheEnabled)
      Enables the memory map cache. When enabled the memory mapped portions of the files are cached and shared (giving each thread a clone of it)

    • exists

      public boolean exists(ShpFileType fileType) throws IllegalArgumentException
      Returns true if the file exists. Throws an exception if the file is not local.
      Parameters:
      fileType - the type of file to check existance for.
      Returns:
      true if the file exists.
      Throws:
      IllegalArgumentException - if the files are not local.