ExtractTopLevelDomain.java
No OneTemporary
Actions

Subscribers

None

File Metadata

	package org.warcbase.pig.piggybank;

	import java.io.IOException;
	import java.net.URL;

	import org.apache.pig.EvalFunc;
	import org.apache.pig.data.Tuple;

	/**
	* UDF for extracting the top-level domain from an URL. Extracts the hostname from the first
	* argument; if it's <code>null</code>, extracts the hostname from the second argument. The second
	* argument is typically a source page, e.g., if the first URL is a relative URL, take the host from
	* the source page.
	*/
	public class ExtractTopLevelDomain extends EvalFunc<String> {
	public String exec(Tuple input) throws IOException {
	if (input == null \|\| input.size() == 0 \|\| input.get(0) == null) {
	return null;
	}

	String host = null;
	try {
	host = (new URL((String) input.get(0))).getHost();
	} catch (Exception e) {
	// It's okay, just fall through here.
	}

	if (host != null \|\| (host == null && input.size() == 0)) {
	return host;
	}

	try {
	return (new URL((String) input.get(1))).getHost();
	} catch (Exception e) {
	return null;
	}
	}
	}