Package org.apache.hadoop.util

Class ToolRunner

java.lang.Object

org.apache.hadoop.util.ToolRunner

@Public
@Stable
public class ToolRunner
extends Object

A utility to help run Tools.

ToolRunner can be used to run classes implementing Tool interface. It works in conjunction with GenericOptionsParser to parse the generic hadoop command line arguments and modifies the Configuration of the Tool. The application-specific options are passed along without being modified.

See Also:

• Tool
• GenericOptionsParser

Constructor Summary

Constructors

Constructor	Description
ToolRunner()

Method Summary

Modifier and Type	Method	Description
static boolean	confirmPrompt(String prompt)	Print out a prompt to the user, and return true if the user responds with "y" or "yes".
static void	printGenericCommandUsage(PrintStream out)	Prints generic command-line argurments and usage information.
static int	run(Configuration conf, Tool tool, String[] args)	Runs the given Tool by Tool.run(String[]), after parsing with the given generic arguments.
static int	run(Tool tool, String[] args)	Runs the Tool with its Configuration.

Methods inherited from class java.lang.Object

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

Constructor Details

ToolRunner

public ToolRunner()

Method Details

run

public static int run(Configuration conf,
 Tool tool,
 String[] args)
               throws Exception

Runs the given Tool by Tool.run(String[]), after parsing with the given generic arguments. Uses the given Configuration, or builds one if null. Sets the Tool's configuration with the possibly modified version of the conf.

Parameters:

conf - Configuration for the Tool.

tool - Tool to run.

args - command-line arguments to the tool.

Returns:

exit code of the Tool.run(String[]) method.

Throws:

Exception - Exception.

run

public static int run(Tool tool,
 String[] args)
               throws Exception

Runs the Tool with its Configuration. Equivalent to run(tool.getConf(), tool, args).

Parameters:

tool - Tool to run.

args - command-line arguments to the tool.

Returns:

exit code of the Tool.run(String[]) method.

Throws:

Exception - exception.

printGenericCommandUsage

public static void printGenericCommandUsage(PrintStream out)

Prints generic command-line argurments and usage information.

Parameters:

out - stream to write usage information to.

confirmPrompt

public static boolean confirmPrompt(String prompt)
                             throws IOException

Print out a prompt to the user, and return true if the user responds with "y" or "yes". (case insensitive).

Parameters:

prompt - prompt.

Returns:

if the user responds with "y" or "yes". (case insensitive) true, not false.

Throws:

IOException - raised on errors performing I/O.