/*
* 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 org.apache.flink.api.java.tuple;
import org.apache.flink.types.NullFieldException;
/**
* The base class of all tuples. Tuples have a fix length and contain a set of fields,
* which may all be of different types. Because Tuples are strongly typed, each distinct
* tuple length is represented by its own class. Tuples exists with up to 25 fields and
* are described in the classes {@link Tuple1} to {@link Tuple25}.
* <p>
* The fields in the tuples may be accessed directly a public fields, or via position (zero indexed)
* {@link #getField(int)}.
* <p>
* Tuples are in principle serializable. However, they may contain non-serializable fields,
* in which case serialization will fail.
*/
public abstract class Tuple implements java.io.Serializable {
private static final long serialVersionUID = 1L;
public static final int MAX_ARITY = 25;
/**
* Gets the field at the specified position.
*
* @param pos The position of the field, zero indexed.
* @return The field at the specified position.
* @throws IndexOutOfBoundsException Thrown, if the position is negative, or equal to, or larger than the number of fields.
*/
public abstract <T> T getField(int pos);
/**
* Gets the field at the specified position, throws NullFieldException if the field is null. Used for comparing key fields.
*
* @param pos The position of the field, zero indexed.
* @return The field at the specified position.
* @throws IndexOutOfBoundsException Thrown, if the position is negative, or equal to, or larger than the number of fields.
* @throws NullFieldException Thrown, if the field at pos is null.
*/
public <T> T getFieldNotNull(int pos){
T field = getField(pos);
if (field != null) {
return field;
} else {
throw new NullFieldException(pos);
}
}
/**
* Sets the field at the specified position.
*
* @param value The value to be assigned to the field at the specified position.
* @param pos The position of the field, zero indexed.
* @throws IndexOutOfBoundsException Thrown, if the position is negative, or equal to, or larger than the number of fields.
*/
public abstract <T> void setField(T value, int pos);
/**
* Gets the number of field in the tuple (the tuple arity).
*
* @return The number of fields in the tuple.
*/
public abstract int getArity();
}