JournalComparer.java #2

package journal.reader;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.text.ParseException;
import java.util.zip.GZIPInputStream;

public class JournalComparer {

	private String file1;
	private String file2;
	
	private DataProvider provider1;
	private DataProvider provider2;
	
	private int lineCounter;
	
	public JournalComparer(String file1, String file2, int lineCounter) {
		this.file1 = file1;
		this.file2 = file2;
		this.lineCounter = lineCounter;
	}
	
	static class DataProvider {
		private String filename;
		private JournalParser parser;
		private int lineCounter;
		private int line = 0;
		
		public DataProvider(String filename, int lineCounter) throws FileNotFoundException {
			this.filename = filename;
			this.lineCounter = lineCounter;
			InputStream in = new FileInputStream(filename);
			if (filename.endsWith(".gz")) {
				try {
					in = new GZIPInputStream(in);
				} catch (IOException e) {
					e.printStackTrace();
					System.exit(1);
				}
			}
			parser = new JournalParser(new InputStreamReader(in), new Options());
		}

		
		public DataJournalEntry next() throws ParseException, IOException {
			JournalEntry entry = parser.parseNext();
			line++;
			
			if (lineCounter > 0 && line > 0 && line % lineCounter == 0) {
				System.err.println(filename + " : " + line);
			}

			if (entry instanceof TransactionJournalEntry) {
				entry = parser.parseNext();
				line++;
				
				if (entry == null) {
					return null;
				}
			}
			
			return (DataJournalEntry) entry;
		}
	}
	
	public void run() throws ParseException, IOException {
		provider1 = new DataProvider(file1, lineCounter);
		provider2 = new DataProvider(file2, lineCounter);
				
		DataJournalEntry data1 = provider1.next();
		DataJournalEntry data2 = provider2.next();
		
		while (data1 != null && data2 != null) {
			int compare = data1.compareTo(data2);
			if (compare == 0) {
				if (! data1.equals(data2)) {
					System.out.println("Entries differ : ");
					System.out.println("1 : " + data1.toJournalString());
					System.out.println("2 : " + data2.toJournalString());
				}
				
				data1 = provider1.next();
				data2 = provider2.next();
				
				continue;
			}
			else if (compare < 0) {
				System.out.println("1 : " + data1.toJournalString());
				data1 = provider1.next();
			}
			else { // compare > 0
				System.out.println("2 : " + data2.toJournalString());
				data2 = provider2.next();
			}
		}
		
		while (data1 != null) {
			System.out.println("1 : " + data1.toJournalString());
			data1 = provider1.next();
		}

		while (data2 != null) {
			System.out.println("2 : " + data2.toJournalString());
			data2 = provider2.next();
		}
	}
	
	public static void main(String[] args) {
		if (args.length < 2) {
			System.out.println("Usage : journal.reader.JournalComparer <file1> <file2> [linecounter]");
			System.exit(1);
		}

		String file1 = args[0];
		String file2 = args[1];
		int lineCounter = 0;
		if (args.length == 3) {
			lineCounter = Integer.parseInt(args[2]);
		}
		
		JournalComparer comp = new JournalComparer(file1, file2, lineCounter);
		
		try {
			comp.run();
		}
		catch (Exception e) {
			e.printStackTrace();
		}
	}

}