/*
* Copyright 2007 Kasper B. Graversen
*
* 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 org.supercsv.io;
import java.io.IOException;
import java.util.List;
import org.supercsv.cellprocessor.ift.CellProcessor;
import org.supercsv.exception.SuperCsvConstraintViolationException;
import org.supercsv.exception.SuperCsvException;
/**
* Interface for readers that read into Lists.
*
* @author Kasper B. Graversen
* @author James Bassett
*/
public interface ICsvListReader extends ICsvReader {
/**
* Reads a row of a CSV file and returns a List of Strings containing each column. If you are forced to use this
* method instead of {@link #read(CellProcessor...)} because your CSV file has a variable number of columns, then
* you can call the {@link #executeProcessors(CellProcessor...)} method after calling {@link #read()} to execute the
* cell processors manually (after determining the number of columns read in and which cell processors to use).
*
* @return the List of columns, or null if EOF
* @throws IOException
* if an I/O error occurred
* @throws SuperCsvException
* if there was a general exception while reading/processing
* @since 1.0
*/
List<String> read() throws IOException;
/**
* Reads a row of a CSV file and returns a List of Objects containing each column. The data can be further processed
* by cell processors (each element in the processors array corresponds with a CSV column). A <tt>null</tt> entry in
* the processors array indicates no further processing is required (the unprocessed String value will be added to
* the List). Prior to version 2.0.0 this method returned a List of Strings.
*
* @param processors
* an array of CellProcessors used to further process data before it is added to the List (each element
* in the processors array corresponds with a CSV column - the number of processors should match the
* number of columns). A <tt>null</tt> entry indicates no further processing is required (the unprocessed
* String value will be added to the List).
* @return the List of columns, or null if EOF
* @throws IOException
* if an I/O error occurred
* @throws NullPointerException
* if processors is null
* @throws SuperCsvConstraintViolationException
* if a CellProcessor constraint failed
* @throws SuperCsvException
* if there was a general exception while reading/processing
* @since 1.0
*/
List<Object> read(CellProcessor... processors) throws IOException;
/**
* Executes the supplied cell processors on the last row of CSV that was read. This should only be used when the
* number of CSV columns is unknown before the row is read, and you are forced to use {@link #read()} instead of
* {@link #read(CellProcessor...)}.
*
* @param processors
* an array of CellProcessors used to further process the last row of CSV data that was read (each
* element in the processors array corresponds with a CSV column - the number of processors should match
* the number of columns). A <tt>null</tt> entry indicates no further processing is required (the
* unprocessed String value will be added to the List).
* @return the List of processed columns
* @throws NullPointerException
* if processors is null
* @throws SuperCsvConstraintViolationException
* if a CellProcessor constraint failed
* @throws SuperCsvException
* if the wrong number of processors are supplied, or CellProcessor execution failed
* @since 2.1.0
*/
List<Object> executeProcessors(CellProcessor... processors);
}
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