Csv.java
/*
* Copyright (c) 2001-2017, Zoltan Farkas All Rights Reserved.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* Additionally licensed with:
*
* 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.spf4j.io;
import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
import java.io.File;
import java.io.IOException;
import java.io.Reader;
import java.io.StringReader;
import java.io.UncheckedIOException;
import java.nio.charset.Charset;
import java.util.List;
import java.util.Map;
import javax.annotation.CheckReturnValue;
import javax.annotation.ParametersAreNonnullByDefault;
import org.spf4j.base.CharSequences;
import org.spf4j.io.csv.CharSeparatedValues;
import org.spf4j.io.csv.CsvParseException;
import org.spf4j.io.csv.CsvReader;
/**
* Supports CSV format as described at: https://en.wikipedia.org/wiki/Comma-separated_values. either of \n \r or \r\n
* are valid end of line delimiters
*
* why another implementation? because I need one that is as fast as possible, and as flexible as possible.
*
* @author zoly
*/
@ParametersAreNonnullByDefault
@SuppressFBWarnings("NP_LOAD_OF_KNOWN_NULL_VALUE") // FB gets it wrong here
public final class Csv {
public static final CharSeparatedValues CSV = new CharSeparatedValues(',');
private static final char[] TO_ESCAPE = new char[]{',', '\n', '\r', '"'};
private Csv() {
}
public interface CsvHandler<T> extends org.spf4j.io.csv.CsvHandler<T> {
}
public interface CsvRowHandler<T> extends org.spf4j.io.csv.CsvRowHandler<T> {
}
public interface CsvMapHandler<T> extends org.spf4j.io.csv.CsvMapHandler<T> {
}
public static String[] readSystemProperty(final String propertyName, final String... defaults) {
String propertyVal = System.getProperty(propertyName);
if (propertyVal == null) {
return defaults;
} else {
List<String> row;
try {
row = readRow(propertyVal);
} catch (CsvParseException ex) {
throw new RuntimeException("Unable to parser property " + propertyName + " = " + propertyVal, ex);
}
return row.toArray(new String[row.size()]);
}
}
public static void writeCsvRow(final Appendable writer, final Object... elems) throws IOException {
CSV.writeCsvRow(writer, elems);
}
public static void writeCsvRow2(final Appendable writer, final Object obj, final Object... elems)
throws IOException {
CSV.writeCsvRow2(writer, obj, elems);
}
public static void writeCsvRow(final Appendable writer, final long... elems) throws IOException {
CSV.writeCsvRow(writer, elems);
}
public static void writeCsvRowNoEOL(final long[] elems, final Appendable writer) throws IOException {
CSV.writeCsvRowNoEOL(elems, writer);
}
public static void writeCsvRow(final Appendable writer, final Iterable<?> elems) throws IOException {
CSV.writeCsvRow(writer, elems);
}
public static void writeCsvRowNoEOL(final Iterable<?> elems, final Appendable writer) throws IOException {
CSV.writeCsvRowNoEOL(elems, writer);
}
public static <T> T read(final File file, final Charset charset,
final CsvMapHandler<T> handler) throws IOException, CsvParseException {
return CSV.read(file, charset, handler);
}
public static <T> T read(final File file, final Charset charset,
final CsvHandler<T> handler) throws IOException, CsvParseException {
return CSV.read(file, charset, handler);
}
public static List<Map<String, String>> read(final Reader preader) throws IOException, CsvParseException {
return CSV.read(preader);
}
public static <T> T read(final Reader preader,
final CsvMapHandler<T> handler) throws IOException, CsvParseException {
return CSV.read(preader, handler);
}
public static List<String> readRow(final String row) throws CsvParseException {
try {
return readRow(new StringReader(row));
} catch (IOException ex) {
throw new UncheckedIOException(ex);
}
}
public static List<String> readRow(final Reader reader) throws IOException, CsvParseException {
return CSV.readRow(reader);
}
public static <T> T readRow(final Reader reader, final CsvRowHandler<T> handler)
throws IOException, CsvParseException {
return CSV.readRow(reader, handler);
}
public static <T> T read(final Reader preader,
final CsvHandler<T> handler) throws IOException, CsvParseException {
return CSV.read(preader, handler);
}
/**
* reads CSV format until EOF of reader.
*
* @param <T>
* @param preader
* @param handler
* @return
* @throws IOException
*/
public static <T> T readNoBom(final PushbackReader reader, final CsvHandler<T> handler)
throws IOException, CsvParseException {
return CSV.readNoBom(reader, handler);
}
/**
* read a CSV stream, as a Iterable over rows.
* the List<String> instance is reused during iteration, you will need to copy content into
* own data structure.
* @param preader
* @return
*/
public static Iterable<Iterable<String>> asIterable(final Reader preader) {
return CSV.asIterable(preader);
}
public static CsvReader reader(final Reader preader) throws IOException {
return CSV.reader(preader);
}
public static CsvReader readerNoBOM(final PushbackReader reader) {
return CSV.readerNoBOM(reader);
}
public static void writeCsvElement(final CharSequence elem, final Appendable writer) throws IOException {
if (CharSequences.containsAnyChar(elem, TO_ESCAPE)) {
writeQuotedCsvElement(elem, writer);
} else {
writer.append(elem);
}
}
public static void writeQuotedCsvElement(final CharSequence elem, final Appendable writer) throws IOException {
int length = elem.length();
writer.append('"');
for (int i = 0; i < length; i++) {
char c = elem.charAt(i);
if (c == '"') {
writer.append("\"\"");
} else {
writer.append(c);
}
}
writer.append('"');
}
public static CharSequence toCsvElement(final CharSequence elem) {
if (CharSequences.containsAnyChar(elem, TO_ESCAPE)) {
StringBuilder sw = new StringBuilder(elem.length() + 2);
try {
writeQuotedCsvElement(elem, sw);
} catch (IOException ex) {
throw new UncheckedIOException(ex);
}
return sw.toString();
} else {
return elem;
}
}
/**
* returns next character.
*
* @param reader
* @param addElemTo
* @return - next character or -1 if eof has been reached.
* @throws IOException
*/
@CheckReturnValue
public static int readCsvElement(final Reader reader, final StringBuilder addElemTo) throws IOException {
int c = reader.read();
if (c < 0) {
return c;
}
if (c == '"') {
c = reader.read();
while (c >= 0) {
if (c == '"') {
int c2 = reader.read();
if (c2 >= 0) {
if (c2 == '"') {
addElemTo.append((char) c);
} else {
return c2;
}
} else {
return c2;
}
} else {
addElemTo.append((char) c);
}
c = reader.read();
}
} else {
while (c != ',' && c != '\n' && c != '\r' && c >= 0) {
addElemTo.append((char) c);
c = reader.read();
}
}
return c;
}
}