uk.ac.starlink.util

Class ProcessDataSource

java.lang.Object

uk.ac.starlink.util.DataSource

uk.ac.starlink.util.ProcessDataSource

public class ProcessDataSource
extends DataSource

DataSource that uses the standard output of a System process.

Since:

24 Mar 2015

Author:

Mark Taylor

Field Summary

Fields inherited from class uk.ac.starlink.util.DataSource

DEFAULT_INTRO_LIMIT, MARK_WORKAROUND_PROPERTY

Constructor Summary

Constructors

Constructor and Description
ProcessDataSource(ProcessBuilder pbuilder) Constructor.

Method Summary

Modifier and Type	Method and Description
static ProcessBuilder	createCommandLineProcessBuilder(String cmdLine) Utility method to create a process builder given a shell command line that generates output to standard output.
protected InputStream	getRawInputStream() Provides a new InputStream for this data source.

Methods inherited from class uk.ac.starlink.util.DataSource

close, forceCompression, getCompression, getHybridInputStream, getInputStream, getInputStream, getIntro, getIntroLimit, getLength, getMarkWorkaround, getName, getPosition, getRawLength, getSystemId, getURL, makeDataSource, makeDataSource, makeDataSource, setCompression, setIntroLimit, setMarkWorkaround, setName, setPosition, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

ProcessDataSource

public ProcessDataSource(ProcessBuilder pbuilder)

Constructor.

Parameters:

pbuilder - process builder

Method Detail

getRawInputStream

protected InputStream getRawInputStream()
                                 throws IOException

Description copied from class: DataSource

Provides a new InputStream for this data source. This method should be implemented by subclasses to provide a new InputStream giving the raw content of the source each time it is called. The general contract of this method is that each time it is called it will return a stream with the same content.

Specified by:

getRawInputStream in class DataSource

Returns:

an InputStream containing the data of this source

Throws:

IOException

createCommandLineProcessBuilder

public static ProcessBuilder createCommandLineProcessBuilder(String cmdLine)

Utility method to create a process builder given a shell command line that generates output to standard output. The command line may contain shell syntax like | symbols.

This method simply sets up a ProcessBuilder to execute a process with the argv { "sh", "-c", cmdLine }. I haven't tested this exhaustively, but I'd expect it to work on un*x-like systems. I've got no idea if there's any chance of getting something like this to work on MS Windows, or even if such a thing would be any use.

Parameters:

cmdLine - shell command that generates output to stdout

Returns:

process builder to execute cmdLine