Package com.thebuzzmedia.exiftool.core.strategies

Class PoolStrategy

java.lang.Object

com.thebuzzmedia.exiftool.core.strategies.PoolStrategy

All Implemented Interfaces:

ExecutionStrategy, AutoCloseable

public class PoolStrategy
extends Object
implements ExecutionStrategy

Implementation of ExecutionStrategy using a pool of strategies. Each time {execute(CommandExecutor, String, List, OutputHandler) method is called, an internal strategy from the pool is picked and return to the pool once work is finished. This strategy should be used in a multithreaded environment, when application need to extract exif data from images in parallel.

Constructor Summary

Constructors

Constructor	Description
PoolStrategy(Collection<ExecutionStrategy> strategies)	Create the pool.

Method Summary

Modifier and Type	Method	Description
void	close()	This method should be used to: Close remaining process (if any). Clean previous executions. For instance, with the stay_open flag, this method should: Close opened process. Stop task used to automatically close process. Once closed, ExifTool should still be able to use this strategy if a call to ExecutionStrategy.execute(com.thebuzzmedia.exiftool.process.CommandExecutor, java.lang.String, java.util.List<java.lang.String>, com.thebuzzmedia.exiftool.process.OutputHandler) is made.
void	execute(CommandExecutor executor, String exifTool, List<String> arguments, OutputHandler handler)	Execute exiftool command.
boolean	isRunning()	Check if exiftool process is currently running.
boolean	isSupported(Version version)	Check if this strategy should is supported with this specific version.
void	shutdown()	Shutdown the strategy.

Methods inherited from class java.lang.Object

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

Constructor Detail

PoolStrategy

public PoolStrategy(Collection<ExecutionStrategy> strategies)

Create the pool.

Parameters:

strategies - Internal strategies.

Throws:

NullPointerException - If strategies is null.

IllegalArgumentException - If strategies is empty.

Method Detail

execute

public void execute(CommandExecutor executor,
                    String exifTool,
                    List<String> arguments,
                    OutputHandler handler)
             throws IOException

Description copied from interface: ExecutionStrategy

Execute exiftool command.

Specified by:

execute in interface ExecutionStrategy

Parameters:

executor - ExifTool withExecutor.

exifTool - ExifTool withPath.

arguments - Command line arguments.

handler - Handler to read command output.

Throws:

IOException - If an error occurred during execution.

isRunning

public boolean isRunning()

Description copied from interface: ExecutionStrategy

Check if exiftool process is currently running. This method is important especially if stay_open flag has been enabled.

Specified by:

isRunning in interface ExecutionStrategy

Returns:

true if exiftool process is currently open, false otherwise.

isSupported

public boolean isSupported(Version version)

Description copied from interface: ExecutionStrategy

Check if this strategy should is supported with this specific version.

Specified by:

isSupported in interface ExecutionStrategy

Parameters:

version - ExifTool Version.

Returns:

true if this strategy may be used safely with this specific version, false otherwise.

close

public void close()
           throws Exception

Description copied from interface: ExecutionStrategy

This method should be used to:

• Close remaining process (if any).
• Clean previous executions.

For instance, with the stay_open flag, this method should:

• Close opened process.
• Stop task used to automatically close process.

Once closed, ExifTool should still be able to use this strategy if a call to ExecutionStrategy.execute(com.thebuzzmedia.exiftool.process.CommandExecutor, java.lang.String, java.util.List<java.lang.String>, com.thebuzzmedia.exiftool.process.OutputHandler) is made.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface ExecutionStrategy

Throws:

Exception - If an error occurred while stopping exiftool client.

shutdown

public void shutdown()
              throws Exception

Description copied from interface: ExecutionStrategy

Shutdown the strategy.

Specified by:

shutdown in interface ExecutionStrategy

Throws:

Exception - If an error occurred while stopping exiftool client.