Lambda expressions demo - difference between Java 7 and Java 8

DataLoader - Java 7

		MapFileParser parser = new MapFileParser(filename);
		parser.readMapFile(new MapProcessor() {
			
			@Override
			public void process(Map<String, String> map) 
			{
				database.add(map);
			}
		});

DataLoader - Java 8

		MapFileParser parser = new MapFileParser(filename);
		parser.readMapFile( (map) -> { database.add(map); } );

MapFileParser - Java 7

	public void readMapFile(MapProcessor processor) throws IOException 
	{
		try (BufferedReader reader = new BufferedReader(new FileReader(filename))) 
		{
			String line = reader.readLine();
			while (line != null)
			{
				Map<String, String> map = parseLineIntoMap(line);
				processor.process(map);
				line = reader.readLine();
			}
		}
		
	}

MapFileParser - Java 8

	public void readMapFile(final Consumer<Map<String, String>> processor) throws IOException 
	{
		try (BufferedReader reader = new BufferedReader(new FileReader(filename))) 
		{
			String line = reader.readLine();
			while (line != null)
			{
				Map<String, String> map = parseLineIntoMap(line);
				processor.accept(map);
				line = reader.readLine();
			}
		}
	}

MapProcessor - Java 7

public interface MapProcessor
{
	void process(Map<String, String> map);
}