Package org.springframework.core.io

Class AbstractResource

java.lang.Object
org.springframework.core.io.AbstractResource
All Implemented Interfaces:
InputStreamSource, Resource
Direct Known Subclasses:
AbstractFileResolvingResource, ByteArrayResource, DescriptiveResource, FileSystemResource, InputStreamResource, PathResource, VfsResource
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.

Since:
28.12.2003
Author:
Juergen Hoeller, Sam Brannen

  • 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

    • isReadable

      public boolean isReadable()
      This implementation always returns true for a resource that exists (revised as of 5.1).
      Specified by:
      isReadable in interface Resource
      See Also:

    • isOpen

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

    • isFile

      public boolean isFile()
      This implementation always returns false.
      Specified by:
      isFile in interface Resource
      See Also:

    • 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
      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
      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
      Throws:
      FileNotFoundException - if the resource cannot be resolved as absolute file path, i.e. if the resource is not available in a file system
      IOException - in case of general resolution/reading failures
      See Also:

    • readableChannel

      public ReadableByteChannel readableChannel() throws IOException
      This implementation returns Channels.newChannel(InputStream) with the result of InputStreamSource.getInputStream().

      This is the same as in Resource's corresponding default method but mirrored here for efficient JVM-level dispatching in a class hierarchy.

      Specified by:
      readableChannel in interface Resource
      Returns:
      the byte channel for the underlying resource (must not be null)
      Throws:
      FileNotFoundException - if the underlying resource doesn't exist
      IOException - if the content channel could not be opened
      See Also:

    • contentLength

      public long contentLength() throws IOException
      This method reads the entire InputStream to determine the content length.

      For a custom sub-class of InputStreamResource, we strongly recommend overriding this method with a more optimal implementation, e.g. checking File length, or possibly simply returning -1 if the stream can only be read once.

      Specified by:
      contentLength in interface Resource
      Throws:
      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
      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:
      FileNotFoundException - if the resource cannot be resolved as an absolute file path, i.e. is not available in a file system
      IOException - in case of general resolution/reading failures

    • 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

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

    • equals

      public boolean equals(@Nullable Object other)
      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:

    • toString

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