net.sf.okapi.lib.terminology.tsv.TSVReader Maven / Gradle / Ivy

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/*===========================================================================
  Copyright (C) 2010 by the Okapi Framework contributors
-----------------------------------------------------------------------------
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at

  http://www.apache.org/licenses/LICENSE-2.0

  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
===========================================================================*/

package net.sf.okapi.lib.terminology.tsv;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

import net.sf.okapi.common.BOMAwareInputStream;
import net.sf.okapi.common.LocaleId;
import net.sf.okapi.common.exceptions.OkapiIOException;
import net.sf.okapi.lib.terminology.ConceptEntry;
import net.sf.okapi.lib.terminology.IGlossaryReader;

public class TSVReader implements IGlossaryReader {

	private ConceptEntry nextEntry;
	private BufferedReader reader;
	private LocaleId srcLoc;
	private LocaleId trgLoc;

	public TSVReader (LocaleId srcLoc,
		LocaleId trgLoc)
	{
		this.srcLoc = srcLoc;
		this.trgLoc = trgLoc;
	}
	
	@Override
	public void open (File file) {
		try {
			open(new FileInputStream(file));
		}
		catch ( Throwable e) {
			throw new OkapiIOException("Error opening the URI.\n" + e.getLocalizedMessage());
		}
	}

	@Override
	public void open (InputStream input) {
		try {
			close();

			// Deal with the potential BOM
			String encoding = "UTF-8";
			// bis is closed when reader is closed by Ifilter.close()
			BOMAwareInputStream bis = new BOMAwareInputStream(input, encoding);
			encoding = bis.detectEncoding();
			// Open the input document with BOM-aware reader
			reader = new BufferedReader(new InputStreamReader(bis, encoding));
			
			// Read the first entry
			readNext();
		}
		catch ( Throwable e) {
			throw new OkapiIOException("Error opening the URI.\n" + e.getLocalizedMessage());
		}
	}

	@Override
	public void close () {
		nextEntry = null;
		try {
			if ( reader != null ) {
				reader.close();
				reader = null;
			}
		}
		catch ( IOException e) {
			throw new OkapiIOException(e);
		}
	}

	@Override
	public boolean hasNext () {
		return (nextEntry != null);
	}

	@Override
	public ConceptEntry next () {
		ConceptEntry currentEntry = nextEntry; // Next entry becomes the current one
		readNext(); // Parse the new next entry
		return currentEntry; // Send the current entry
	}

	private void readNext () {
		try {
			nextEntry = null;
			String parts[];
			
			while ( true ) {
				String line = reader.readLine();
				// Check if we reached the end
				if ( line == null ) return;
				// Skip empty and blank lines
				line = line.trim();
				if ( line.isEmpty() ) continue;
				// Split the line into fields
				parts = line.split("\\t");
				// Use only if we have at least source and target
				if ( parts.length > 1 ) break;
			}
			
			ConceptEntry cent = new ConceptEntry();
			cent.addTerm(srcLoc, parts[0]);
			cent.addTerm(trgLoc, parts[1]);
			nextEntry = cent;
		}
		catch ( Throwable e ) {
			throw new OkapiIOException("Error when reading." + e.getLocalizedMessage(), e);
		}
	}

}