org.archive.wayback.core

Class Resource

java.lang.Object

java.io.InputStream

org.archive.wayback.core.Resource

All Implemented Interfaces:

Closeable, AutoCloseable

Direct Known Subclasses:

ArcResource, CompositeResource, GzipDecodingResource, JWATResource, RobotsTxtResource, WarcResource

public abstract class Resource
extends InputStream

Abstraction on top of a document stored in a WaybackCollection. TODO: This implementation needs some pretty drastic refactoring.. May have to wait for 2.0. This should be a byte-oriented record, and allow wrapping the interior byte-stream in on the more full featured HTTP libraries (jetty/apache-http-client/w3c-http-reference). For now, it is a system-wide assumption that all resources are HTTP based. TODO: Some code downcasts Resource to its sub-classes to gain access to methods only available in specific implementation. Consider adding more methods to make downcast unnecessary. More sub-classes are expected, for encapsulating revisit-original pair of Resources as single Resource, for example.

Author:

Brad Tofel

See Also:

ResourceStore.retrieveResource(CaptureSearchResult)

Constructor Summary

Constructors

Constructor and Description
Resource()

Method Summary

Methods

Modifier and Type	Method and Description
int	available()
abstract void	close()
String	getHeader(String headerName)
abstract Map<String,String>	getHttpHeaders() Assumes an HTTP response - return the HTTP headers, not including the HTTP Message header
abstract long	getRecordLength()
String	getRefersToDate() return WARC-Refers-To-Date WARC record header value or equivalent.
String	getRefersToTargetURI() return WARC-Refer-To-Target-URI WARC record header value or equivalent.
abstract int	getStatusCode() Assumes an HTTP resource - return the HTTP response code
void	mark(int readlimit)
boolean	markSupported()
void	parseHeaders()
int	read()
int	read(byte[] b)
int	read(byte[] b, int off, int len)
void	reset()
void	setChunkedEncoding() indicate that there is a Transfer-Encoding: chunked header, so the input data should be dechunked as it is read.
protected void	setInputStream(InputStream is)
long	skip(long n)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Resource

public Resource()

Method Detail

close

public abstract void close()
                    throws IOException

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Overrides:

close in class InputStream

Throws:

IOException

getStatusCode

public abstract int getStatusCode()

Assumes an HTTP resource - return the HTTP response code

Returns:

the HTTP response code from the HTTP message

getRecordLength

public abstract long getRecordLength()

Returns:

the size in bytes of the record payload, including HTTP header

getHttpHeaders

public abstract Map<String,String> getHttpHeaders()

Assumes an HTTP response - return the HTTP headers, not including the HTTP Message header

Returns:

key-value Map of HTTP headers

getRefersToTargetURI

public String getRefersToTargetURI()

return WARC-Refer-To-Target-URI WARC record header value or equivalent. Default implementation returns null.

Returns:

header value (URI)

getRefersToDate

public String getRefersToDate()

return WARC-Refers-To-Date WARC record header value or equivalent. Default implementation returns null

Returns:

14-digit timestamp string (yyyyMMddHHmmss)

parseHeaders

public void parseHeaders()
                  throws IOException

Throws:

IOException

getHeader

public String getHeader(String headerName)

setInputStream

protected void setInputStream(InputStream is)

setChunkedEncoding

public void setChunkedEncoding()
                        throws IOException

indicate that there is a Transfer-Encoding: chunked header, so the input data should be dechunked as it is read. This method actually peeks ahead to verify that there is a hex-encoded chunk length before assuming the data is chunked.

Throws:

IOException - for usual reasons

available

public int available()
              throws IOException

Overrides:

available in class InputStream

Throws:

IOException

mark

public void mark(int readlimit)

Overrides:

mark in class InputStream

markSupported

public boolean markSupported()

Overrides:

markSupported in class InputStream

read

public int read()
         throws IOException

Specified by:

read in class InputStream

Throws:

IOException

read

public int read(byte[] b,
       int off,
       int len)
         throws IOException

Overrides:

read in class InputStream

Throws:

IOException

read

public int read(byte[] b)
         throws IOException

Overrides:

read in class InputStream

Throws:

IOException

reset

public void reset()
           throws IOException

Overrides:

reset in class InputStream

Throws:

IOException

skip

public long skip(long n)
          throws IOException

Overrides:

skip in class InputStream

Throws:

IOException