/*
* Copyright 2015 Oliver Siegmar
*
* 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 de.siegmar.fastcsv.reader;
import java.io.File;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.Reader;
import java.nio.charset.Charset;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.StandardOpenOption;
import java.util.ArrayList;
import java.util.List;
import java.util.Objects;
/**
* This is the main class for reading CSV data.
*
* @author Oliver Siegmar
*/
public final class CsvReader {
/**
* Field separator character (default: ',' - comma).
*/
private char fieldSeparator = ',';
/**
* Text delimiter character (default: '"' - double quotes).
*/
private char textDelimiter = '"';
/**
* Read first line as header line? (default: false).
*/
private boolean ;
/**
* Skip empty rows? (default: true)
*/
private boolean skipEmptyRows = true;
/**
* Throw an exception if CSV data contains different field count? (default: false).
*/
private boolean errorOnDifferentFieldCount;
/**
* Sets the field separator character (default: ',' - comma).
*/
public void setFieldSeparator(final char fieldSeparator) {
this.fieldSeparator = fieldSeparator;
}
/**
* Sets the text delimiter character (default: '"' - double quotes).
*/
public void setTextDelimiter(final char textDelimiter) {
this.textDelimiter = textDelimiter;
}
/**
* Specifies if the first line should be the header (default: false).
*/
public void (final boolean containsHeader) {
this.containsHeader = containsHeader;
}
/**
* Specifies if empty rows should be skipped (default: true).
*/
public void setSkipEmptyRows(final boolean skipEmptyRows) {
this.skipEmptyRows = skipEmptyRows;
}
/**
* Specifies if an exception should be thrown, if CSV data contains different field count
* (default: false).
*/
public void setErrorOnDifferentFieldCount(final boolean errorOnDifferentFieldCount) {
this.errorOnDifferentFieldCount = errorOnDifferentFieldCount;
}
/**
* Reads an entire file and returns a CsvContainer containing the data.
*
* @param file the file to read data from.
* @param charset the character set to use - must not be {@code null}.
* @return the entire file's data - never {@code null}.
* @throws IOException if an I/O error occurs.
*/
public CsvContainer read(final File file, final Charset charset) throws IOException {
return read(
Objects.requireNonNull(file.toPath(), "file must not be null"),
Objects.requireNonNull(charset, "charset must not be null")
);
}
/**
* Reads an entire file and returns a CsvContainer containing the data.
*
* @param path the file to read data from.
* @param charset the character set to use - must not be {@code null}.
* @return the entire file's data - never {@code null}.
* @throws IOException if an I/O error occurs.
*/
public CsvContainer read(final Path path, final Charset charset) throws IOException {
Objects.requireNonNull(path, "path must not be null");
Objects.requireNonNull(charset, "charset must not be null");
try (final Reader reader = newPathReader(path, charset)) {
return read(reader);
}
}
/**
* Reads from the provided reader until the end and returns a CsvContainer containing the data.
*
* This library uses built-in buffering, so you do not need to pass in a buffered Reader
* implementation such as {@link java.io.BufferedReader}.
* Performance may be even likely better if you do not.
*
* @param reader the data source to read from.
* @return the entire file's data - never {@code null}.
* @throws IOException if an I/O error occurs.
*/
public CsvContainer read(final Reader reader) throws IOException {
final CsvParser csvParser =
parse(Objects.requireNonNull(reader, "reader must not be null"));
final List<CsvRow> rows = new ArrayList<>();
CsvRow csvRow;
while ((csvRow = csvParser.nextRow()) != null) {
rows.add(csvRow);
}
if (rows.isEmpty()) {
return null;
}
final List<String> header = containsHeader ? csvParser.getHeader() : null;
return new CsvContainer(header, rows);
}
/**
* Constructs a new {@link CsvParser} for the specified arguments.
*
* @param path the file to read data from.
* @param charset the character set to use - must not be {@code null}.
* @return a new CsvParser - never {@code null}.
* @throws IOException if an I/O error occurs.
*/
public CsvParser parse(final Path path, final Charset charset) throws IOException {
return parse(newPathReader(
Objects.requireNonNull(path, "path must not be null"),
Objects.requireNonNull(charset, "charset must not be null")
));
}
/**
* Constructs a new {@link CsvParser} for the specified arguments.
*
* @param file the file to read data from.
* @param charset the character set to use - must not be {@code null}.
* @return a new CsvParser - never {@code null}.
* @throws IOException if an I/O error occurs.
*/
public CsvParser parse(final File file, final Charset charset) throws IOException {
return parse(
Objects.requireNonNull(file, "file must not be null").toPath(),
Objects.requireNonNull(charset, "charset must not be null")
);
}
/**
* Constructs a new {@link CsvParser} for the specified arguments.
*
* This library uses built-in buffering, so you do not need to pass in a buffered Reader
* implementation such as {@link java.io.BufferedReader}.
* Performance may be even likely better if you do not.
*
* @param reader the data source to read from.
* @return a new CsvParser - never {@code null}.
* @throws IOException if an I/O error occurs.
*/
public CsvParser parse(final Reader reader) throws IOException {
return new CsvParser(Objects.requireNonNull(reader, "reader must not be null"),
fieldSeparator, textDelimiter, containsHeader, skipEmptyRows,
errorOnDifferentFieldCount);
}
private static Reader newPathReader(final Path path, final Charset charset) throws IOException {
return new InputStreamReader(Files.newInputStream(path, StandardOpenOption.READ), charset);
}
}