Package spark.resource

Class AbstractResource

java.lang.Object
spark.resource.AbstractResource
All Implemented Interfaces:
InputStreamResource, Resource
Direct Known Subclasses:
AbstractFileResolvingResource
public abstract class AbstractResource extends Object implements Resource
Convenience base class for Resource implementations, pre-implementing typical behavior.

The "exists" method will check whether a File or InputStream can be opened; "isOpen" will always return false; "getURL" and "getFile" throw an exception; and "toString" will return the description.

  • Constructor Summary

    Constructors
    Constructor
    Description
    AbstractResource()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    long
    contentLength()
    This implementation reads the entire InputStream to calculate the content length.
    Resource
    createRelative(String relativePath)
    This implementation throws a FileNotFoundException, assuming that relative resources cannot be created for this resource.
    boolean
    equals(Object obj)
    This implementation compares description strings.
    boolean
    exists()
    This implementation checks whether a File can be opened, falling back to whether an InputStream can be opened.
    File
    getFile()
    This implementation throws a FileNotFoundException, assuming that the resource cannot be resolved to an absolute file path.
    protected File
    getFileForLastModifiedCheck()
    Determine the File to use for timestamp checking.
    String
    getFilename()
    This implementation always returns null, assuming that this resource type does not have a filename.
    URI
    getURI()
    This implementation builds a URI based on the URL returned by getURL().
    URL
    getURL()
    This implementation throws a FileNotFoundException, assuming that the resource cannot be resolved to a URL.
    int
    hashCode()
    This implementation returns the description's hash code.
    boolean
    isOpen()
    This implementation always returns false.
    boolean
    isReadable()
    This implementation always returns true.
    long
    lastModified()
    This implementation checks the timestamp of the underlying File, if available.
    String
    toString()
    This implementation returns the description of this resource.

    Methods inherited from class java.lang.Object

    clone, finalize, getClass, notify, notifyAll, wait, wait, wait

    Methods inherited from interface spark.resource.InputStreamResource

    getInputStream

    Methods inherited from interface spark.resource.Resource

    getDescription

  • Constructor Details

    • AbstractResource

      public AbstractResource()

  • Method Details

    • exists

      public boolean exists()
      This implementation checks whether a File can be opened, falling back to whether an InputStream can be opened. This will cover both directories and content resources.
      Specified by:
      exists in interface Resource
      Returns:
      if exists

    • isReadable

      public boolean isReadable()
      This implementation always returns true.
      Specified by:
      isReadable in interface Resource
      Returns:
      if readable
      See Also:

    • isOpen

      public boolean isOpen()
      This implementation always returns false.
      Specified by:
      isOpen in interface Resource
      Returns:
      if open

    • getURL

      public URL getURL() throws IOException
      This implementation throws a FileNotFoundException, assuming that the resource cannot be resolved to a URL.
      Specified by:
      getURL in interface Resource
      Returns:
      a URL handle for this resource.
      Throws:
      IOException - if the resource cannot be resolved as URL, i.e. if the resource is not available as descriptor

    • getURI

      public URI getURI() throws IOException
      This implementation builds a URI based on the URL returned by getURL().
      Specified by:
      getURI in interface Resource
      Returns:
      a URI handle for this resource.
      Throws:
      IOException - if the resource cannot be resolved as URI, i.e. if the resource is not available as descriptor

    • getFile

      public File getFile() throws IOException
      This implementation throws a FileNotFoundException, assuming that the resource cannot be resolved to an absolute file path.
      Specified by:
      getFile in interface Resource
      Returns:
      a File handle for this resource.
      Throws:
      IOException - if the resource cannot be resolved as absolute file path, i.e. if the resource is not available in a file system

    • contentLength

      public long contentLength() throws IOException
      This implementation reads the entire InputStream to calculate the content length. Subclasses will almost always be able to provide a more optimal version of this, e.g. checking a File length.
      Specified by:
      contentLength in interface Resource
      Returns:
      the content length for this resource.
      Throws:
      IllegalStateException - if InputStreamResource.getInputStream() returns null.
      IOException - if the resource cannot be resolved (in the file system or as some other known physical resource type)
      See Also:

    • lastModified

      public long lastModified() throws IOException
      This implementation checks the timestamp of the underlying File, if available.
      Specified by:
      lastModified in interface Resource
      Returns:
      the last-modified timestamp for this resource.
      Throws:
      IOException - if the resource cannot be resolved (in the file system or as some other known physical resource type)
      See Also:

    • getFileForLastModifiedCheck

      protected File getFileForLastModifiedCheck() throws IOException
      Determine the File to use for timestamp checking.

      The default implementation delegates to getFile().

      Returns:
      the File to use for timestamp checking (never null)
      Throws:
      IOException - if the resource cannot be resolved as absolute file path, i.e. if the resource is not available in a file system

    • createRelative

      public Resource createRelative(String relativePath) throws IOException
      This implementation throws a FileNotFoundException, assuming that relative resources cannot be created for this resource.
      Specified by:
      createRelative in interface Resource
      Parameters:
      relativePath - the relative path (relative to this resource)
      Returns:
      the resource handle for the relative resource
      Throws:
      IOException - if the relative resource cannot be determined

    • getFilename

      public String getFilename()
      This implementation always returns null, assuming that this resource type does not have a filename.
      Specified by:
      getFilename in interface Resource
      Returns:
      the file name.

    • toString

      public String toString()
      This implementation returns the description of this resource.
      Overrides:
      toString in class Object
      See Also:

    • equals

      public boolean equals(Object obj)
      This implementation compares description strings.
      Overrides:
      equals in class Object
      See Also:

    • hashCode

      public int hashCode()
      This implementation returns the description's hash code.
      Overrides:
      hashCode in class Object
      See Also: