Package com.itextpdf.io.util
Class GhostscriptHelper
java.lang.Object
com.itextpdf.io.util.GhostscriptHelper
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
Modifier and TypeClassDescriptionstatic class
Exceptions thrown when errors occur during generation and comparison of images obtained on the basis of pdf files. -
Field Summary
Modifier and TypeFieldDescriptionstatic final String
The name of the environment variable with the command to execute Ghostscript operations. -
Constructor Summary
ConstructorDescriptionCreates new instance that will rely on Ghostscript execution command defined byGHOSTSCRIPT_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 TypeMethodDescriptionReturns a command that is used to run the utility.void
runGhostScriptImageGeneration
(String pdf, String outDir, String image) Runs Ghostscript to render the PDF's pages as PNG images.void
runGhostScriptImageGeneration
(String pdf, String outDir, String image, String pageList) Runs Ghostscript to render the PDF's pages as PNG images.
-
Field Details
-
GHOSTSCRIPT_ENVIRONMENT_VARIABLE
The name of the environment variable with the command to execute Ghostscript operations.- See Also:
-
-
Constructor Details
-
GhostscriptHelper
public GhostscriptHelper()Creates new instance that will rely on Ghostscript execution command defined byGHOSTSCRIPT_ENVIRONMENT_VARIABLE
environment variable. -
GhostscriptHelper
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 Details
-
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 render the PDF's pages as PNG images.- Parameters:
-
pdf
- Path to the PDF file to be rendered -
outDir
- Path to the output directory, in which the rendered pages will be stored -
image
- String which defines the name of the resultant images. This string will be concatenated with the number of the rendered page from the start of the PDF in "-%03d" format, e.g. "-011" for the eleventh rendered page and so on. This number may not correspond to the actual page number: for example, if the passed pageList equals to "5,3", then images with postfixes "-001.png" and "-002.png" will be created: the former for the third page, the latter for the fifth page. "%" sign in the passed name is prohibited. - 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 render the PDF's pages as PNG images.- Parameters:
-
pdf
- Path to the PDF file to be rendered -
outDir
- Path to the output directory, in which the rendered pages will be stored -
image
- String which defines the name of the resultant images. This string will be concatenated with the number of the rendered page from the start of the PDF in "-%03d" format, e.g. "-011" for the eleventh rendered page and so on. This number may not correspond to the actual page number: for example, if the passed pageList equals to "5,3", then images with postfixes "-001.png" and "-002.png" will be created: the former for the third page, the latter for the fifth page. "%" sign in the passed name is prohibited. -
pageList
- String with numbers of the required pages to be rendered as images. This string should be formatted as a string with numbers, separated by commas, without whitespaces. Can be null, if it is required to render all the PDF's pages. - Throws:
-
IOException
- if there are file's reading/writing issues -
InterruptedException
- if there is thread interruption while executing GhostScript.
-