com.itextpdf.io.util

Class GhostscriptHelper

java.lang.Object

com.itextpdf.io.util.GhostscriptHelper

public class GhostscriptHelper
extends Object

A utility class that is used as an interface to run 3rd-party tool Ghostscript. Ghostscript is an interpreter for the PostScript language and PDF files, it allows to render them as images.

The Ghostscript needs to be installed independently on the system. This class provides a convenient way to run it by passing a terminal command. The command can either be specified explicitly or by a mean of environment variable GHOSTSCRIPT_ENVIRONMENT_VARIABLE.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	GhostscriptHelper.GhostscriptExecutionException Exceptions thrown when errors occur during generation and comparison of images obtained on the basis of pdf files.

Field Summary

Fields

Modifier and Type	Field and Description
static String	GHOSTSCRIPT_ENVIRONMENT_VARIABLE The name of the environment variable with the command to execute Ghostscript operations.

Constructor Summary

Constructors

Constructor and Description
GhostscriptHelper() Creates new instance that will rely on Ghostscript execution command defined by GHOSTSCRIPT_ENVIRONMENT_VARIABLE environment variable.
GhostscriptHelper(String newGsExec) Creates new instance that will rely on Ghostscript execution command defined as passed argument.

Method Summary

Modifier and Type	Method and Description
String	getCliExecutionCommand() Returns a command that is used to run the utility.
void	runGhostScriptImageGeneration(String pdf, String outDir, String image) Runs ghostscript to create images of pdfs.
void	runGhostScriptImageGeneration(String pdf, String outDir, String image, String pageList) Runs ghostscript to create images of specified pages of pdfs.

Methods inherited from class java.lang.Object

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

Field Detail

GHOSTSCRIPT_ENVIRONMENT_VARIABLE

public static final String GHOSTSCRIPT_ENVIRONMENT_VARIABLE

The name of the environment variable with the command to execute Ghostscript operations.

See Also:

Constant Field Values

Constructor Detail

GhostscriptHelper

public GhostscriptHelper()

Creates new instance that will rely on Ghostscript execution command defined by GHOSTSCRIPT_ENVIRONMENT_VARIABLE environment variable.

GhostscriptHelper

public GhostscriptHelper(String newGsExec)

Creates new instance that will rely on Ghostscript execution command defined as passed argument.

Parameters:

newGsExec - the Ghostscript execution command; if null - environment variables will be used instead

Method Detail

getCliExecutionCommand

public String getCliExecutionCommand()

Returns a command that is used to run the utility. This command doesn't contain command parameters. Parameters are added on specific methods invocation.

Returns:

a string command

runGhostScriptImageGeneration

public void runGhostScriptImageGeneration(String pdf,
                                          String outDir,
                                          String image)
                                   throws IOException,
                                          InterruptedException

Runs ghostscript to create images of pdfs.

Parameters:

pdf - Path to the pdf file.

outDir - Path to the output directory

image - Path to the generated image

Throws:

IOException - if there are file's reading/writing issues

InterruptedException - if there is thread interruption while executing GhostScript.

runGhostScriptImageGeneration

public void runGhostScriptImageGeneration(String pdf,
                                          String outDir,
                                          String image,
                                          String pageList)
                                   throws IOException,
                                          InterruptedException

Runs ghostscript to create images of specified pages of pdfs.

Parameters:

pdf - Path to the pdf file.

outDir - Path to the output directory

image - Path to the generated image

pageList - String with numbers of the required pages to extract as image. Should be formatted as string with numbers, separated by commas, without whitespaces. Can be null, if it is required to extract all pages as images.

Throws:

IOException - if there are file's reading/writing issues

InterruptedException - if there is thread interruption while executing GhostScript.