org.gm4java.engine

Interface GMExecutor

All Known Subinterfaces:

GMConnection, GMService

All Known Implementing Classes:

PooledGMService, SimpleGMService

public interface GMExecutor

An interface to execute command using the underlying GraphicsMagick Process.

Author:

Kenneth Xu

Method Summary

Methods

Modifier and Type	Method and Description
String	execute(List<String> command) Executes the command using the underlying GraphicsMagick process.
String	execute(String command, String... arguments) Executes the command using the underlying GraphicsMagick process.

Method Detail

execute

String execute(@Nonnull
             String command,
             String... arguments)
               throws IOException,
                      GMException,
                      GMServiceException

Executes the command using the underlying GraphicsMagick process.

This method can be used in different ways explained in the following sections using an example of drawing text NO IMAGE on a background defined by in.png.

One way is to prepare entire command line with proper space separation of GraphicsMagick arguments and pass it as one single string to command parameter. You don't need to use arguments parameter at all. Using this way, you need to make sure special characters are escaped and arguments with space are quoted. e.g.,

 
 execute("convert in.png -draw \"text 50 100 \"\"NO IMAGE\"\"\" out.png");
 
 

A better way is to pass the command and arguments separately. The same example can now be written as below. Notice that you don't need to add the quotes and escape the quotes anymore.

 
 execute("convert", "in.png", "-draw", "text 50 100 \"NO IMAGE\"", "out.png");
 
 

Parameters:

command - the command to be executed

arguments - arguments of the command.

Returns:

the output from GraphicsMagick as the result of executing the command

Throws:

NullPointerException - when command is null

IOException - when GM encounter IO error executing the command

GMException - when GraphicsMagick returns non-IO error executing the command

GMServiceException - when there is error communicating with the underlying GraphicsMagick process

See Also:

execute(List)

execute

String execute(@Nonnull
             List<String> command)
               throws IOException,
                      GMException,
                      GMServiceException

Executes the command using the underlying GraphicsMagick process. GraphicsMagick command and its arguments are passed in as a list of strings.

Parameters:

command - the command and arguments to be executed

Returns:

the output from GraphicsMagick as the result of executing the command

Throws:

NullPointerException - when command is null

IllegalArgumentException - when command is an empty list.

IOException - when GM encounter IO error executing the command

GMException - when GraphicsMagick returns non-IO error executing the command

GMServiceException - when there is error communicating with the underlying GraphicsMagick process

See Also:

execute(String, String...)