[FLINK-2017] Add predefined required parameters to ParameterTool

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.9
• Fix Version/s: 1.0.0
• Labels: starter
• Assignee: Martin Liesenberg
• Reporter: Robert Metzger
• Created: 15/May/15 08:07
• Updated: 23/Nov/15 14:04
• Resolved: 23/Nov/15 14:04

Description

In FLINK-1525 we've added the ParameterTool.
During the PR review, there was a request for required parameters.

This issue is about implementing a facility to define required parameters. The tool should also be able to print a help menu with a list of all parameters.

This test case shows my initial ideas how to design the API

	@Test
	public void requiredParameters() {
		RequiredParameters required = new RequiredParameters();
		Option input = required.add("input").alt("i").help("Path to input file or directory"); // parameter with long and short variant
		required.add("output"); // parameter only with long variant
		Option parallelism = required.add("parallelism").alt("p").type(Integer.class); // parameter with type
		Option spOption = required.add("sourceParallelism").alt("sp").defaultValue(12).help("Number specifying the number of parallel data source instances"); // parameter with default value, specifying the type.
		Option executionType = required.add("executionType").alt("et").defaultValue("pipelined").choices("pipelined", "batch");
		ParameterUtil parameter = ParameterUtil.fromArgs(new String[]{"-i", "someinput", "--output", "someout", "-p", "15"});

		required.check(parameter);
		required.printHelp();
		required.checkAndPopulate(parameter);

		String inputString = input.get();
		int par = parallelism.getInteger();
		String output = parameter.get("output");
		int sourcePar = parameter.getInteger(spOption.getName());
	}

Issue Links

• is related to: FLINK-1525 Provide utils to pass -D parameters to UDFs