org.apache.tika.batch

Class FileResourceConsumer

java.lang.Object

org.apache.tika.batch.FileResourceConsumer

All Implemented Interfaces:

Callable<IFileProcessorFutureResult>

Direct Known Subclasses:

AbstractFSConsumer

public abstract class FileResourceConsumer
extends Object
implements Callable<IFileProcessorFutureResult>

This is a base class for file consumers. The goal of this class is to abstract out the multithreading and recordkeeping components.

Field Summary

Fields

Modifier and Type	Field and Description
static String	ELAPSED_MILLIS
static String	IO_IS
static String	IO_OS
protected static org.slf4j.Logger	logger
static String	OOM
static String	PARSE_ERR
static String	PARSE_EX
static String	TIMED_OUT

Constructor Summary

Constructors

Constructor and Description
FileResourceConsumer(ArrayBlockingQueue<FileResource> fileQueue)

Method Summary

Methods

Modifier and Type	Method and Description
IFileProcessorFutureResult	call()
org.apache.tika.batch.FileStarted	checkForTimedOutMillis(long staleThresholdMillis) Checks to see if the currentFile being processed (if there is one) should be timed out (still being worked on after staleThresholdMillis).
protected void	close(Closeable closeable)
protected void	flushAndClose(Closeable closeable)
org.apache.tika.batch.FileStarted	getCurrentFile() Returns the name and start time of a file that is currently being processed.
int	getNumHandledExceptions()
int	getNumResourcesConsumed()
protected String	getXMLifiedLogMsg(String type, String resourceId, String... attrs)
protected String	getXMLifiedLogMsg(String type, String resourceId, Throwable t, String... attrs) Use this for structured output that captures resourceId and other attributes.
protected void	incrementHandledExceptions() Make sure to call this appropriately!
boolean	isStillActive() Returns whether or not the consumer is still could process a file or is still processing a file (ACTIVELY_CONSUMING or ASKED_TO_SHUTDOWN)
protected void	parse(String resourceId, Parser parser, InputStream is, ContentHandler handler, Metadata m, ParseContext parseContext) Utility method to handle logging equivalently among all implementing classes.
void	pleaseShutdown() This politely asks the consumer to shutdown.
abstract boolean	processFileResource(FileResource fileResource) Main piece of code that needs to be implemented.

Methods inherited from class java.lang.Object

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

Field Detail

TIMED_OUT

public static String TIMED_OUT

OOM

public static String OOM

IO_IS

public static String IO_IS

IO_OS

public static String IO_OS

PARSE_ERR

public static String PARSE_ERR

PARSE_EX

public static String PARSE_EX

ELAPSED_MILLIS

public static String ELAPSED_MILLIS

logger

protected static org.slf4j.Logger logger

Constructor Detail

FileResourceConsumer

public FileResourceConsumer(ArrayBlockingQueue<FileResource> fileQueue)

Method Detail

call

public IFileProcessorFutureResult call()

Specified by:

call in interface Callable<IFileProcessorFutureResult>

processFileResource

public abstract boolean processFileResource(FileResource fileResource)

Main piece of code that needs to be implemented. Clients are responsible for closing streams and handling the exceptions that they'd like to handle.

Unchecked throwables can be thrown past this, of course. When an unchecked throwable is thrown, this logs the error, and then rethrows the exception. Clients/subclasses should make sure to catch and handle everything they can.

The design goal is that the whole process should close up and shutdown soon after an unchecked exception or error is thrown.

Make sure to call incrementHandledExceptions() appropriately in your implementation of this method.

Parameters:

fileResource - resource to process

Returns:

whether or not a file was successfully processed

incrementHandledExceptions

protected void incrementHandledExceptions()

Make sure to call this appropriately!

isStillActive

public boolean isStillActive()

Returns whether or not the consumer is still could process a file or is still processing a file (ACTIVELY_CONSUMING or ASKED_TO_SHUTDOWN)

Returns:

whether this consumer is still active

pleaseShutdown

public void pleaseShutdown()

This politely asks the consumer to shutdown. Before processing another file, the consumer will check to see if it has been asked to terminate.

This offers another method for politely requesting that a FileResourceConsumer stop processing besides passing it PoisonFileResource.

getCurrentFile

public org.apache.tika.batch.FileStarted getCurrentFile()

Returns the name and start time of a file that is currently being processed. If no file is currently being processed, this will return null.

Returns:

FileStarted or null

getNumResourcesConsumed

public int getNumResourcesConsumed()

getNumHandledExceptions

public int getNumHandledExceptions()

checkForTimedOutMillis

public org.apache.tika.batch.FileStarted checkForTimedOutMillis(long staleThresholdMillis)

Checks to see if the currentFile being processed (if there is one) should be timed out (still being worked on after staleThresholdMillis).

If the consumer should be timed out, this will return the currentFile and set the state to TIMED_OUT.

If the consumer was already timed out earlier or is not processing a file or has been working on a file for less than #staleThresholdMillis, then this will return null.

Parameters:

staleThresholdMillis - threshold to determine whether the consumer has gone stale.

Returns:

null or the file started that triggered the stale condition

getXMLifiedLogMsg

protected String getXMLifiedLogMsg(String type,
                       String resourceId,
                       String... attrs)

getXMLifiedLogMsg

protected String getXMLifiedLogMsg(String type,
                       String resourceId,
                       Throwable t,
                       String... attrs)

Use this for structured output that captures resourceId and other attributes.

Parameters:

type - entity name for exception

resourceId - resourceId string

t - throwable can be null

attrs - (array of key0, value0, key1, value1, etc.)

close

protected void close(Closeable closeable)

flushAndClose

protected void flushAndClose(Closeable closeable)

parse

protected void parse(String resourceId,
         Parser parser,
         InputStream is,
         ContentHandler handler,
         Metadata m,
         ParseContext parseContext)
              throws Throwable

Utility method to handle logging equivalently among all implementing classes. Use, override or avoid as desired.

Parameters:

resourceId - resourceId

parser - parser to use

is - inputStream (will be closed by this method!)

handler - handler for the content

m - metadata

parseContext - parse context

Throws:

Throwable - (logs and then throws whatever was thrown (if anything)