opennlp.tools.ml.model.FileEventStream Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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 opennlp.tools.ml.model;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.Reader;
import java.util.StringTokenizer;
import opennlp.tools.util.ObjectStream;
/**
* Class for using a file of events as an event stream. The format of the file is one event perline with
* each line consisting of outcome followed by contexts (space delimited).
*/
public class FileEventStream implements ObjectStream {
protected final BufferedReader reader;
/**
* Creates a new file event stream from the specified file name.
* @param fileName the name fo the file containing the events.
* @throws IOException When the specified file can not be read.
*/
public FileEventStream(String fileName, String encoding) throws IOException {
this(encoding == null ?
new FileReader(fileName) : new InputStreamReader(new FileInputStream(fileName), encoding));
}
public FileEventStream(String fileName) throws IOException {
this(fileName,null);
}
public FileEventStream(Reader reader) throws IOException {
this.reader = new BufferedReader(reader);
}
/**
* Creates a new file event stream from the specified file.
* @param file the file containing the events.
* @throws IOException When the specified file can not be read.
*/
public FileEventStream(File file) throws IOException {
reader = new BufferedReader(new InputStreamReader(new FileInputStream(file),"UTF8"));
}
@Override
public Event read() throws IOException {
String line;
if ((line = reader.readLine()) != null) {
StringTokenizer st = new StringTokenizer(line);
String outcome = st.nextToken();
int count = st.countTokens();
String[] context = new String[count];
for (int ci = 0; ci < count; ci++) {
context[ci] = st.nextToken();
}
return new Event(outcome, context);
}
else {
return null;
}
}
public void close() throws IOException {
reader.close();
}
/**
* Generates a string representing the specified event.
* @param event The event for which a string representation is needed.
* @return A string representing the specified event.
*/
public static String toLine(Event event) {
StringBuilder sb = new StringBuilder();
sb.append(event.getOutcome());
String[] context = event.getContext();
for (int ci = 0,cl = context.length; ci < cl; ci++) {
sb.append(" ").append(context[ci]);
}
sb.append(System.getProperty("line.separator"));
return sb.toString();
}
@Override
public void reset() throws IOException, UnsupportedOperationException {
throw new UnsupportedOperationException();
}
}