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Super CSV is a fast, programmer-friendly, free CSV package for Java
/*
* 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.prefs;
import org.supercsv.comment.CommentMatcher;
import org.supercsv.encoder.CsvEncoder;
import org.supercsv.encoder.DefaultCsvEncoder;
import org.supercsv.quote.NormalQuoteMode;
import org.supercsv.quote.QuoteMode;
/**
* Before reading or writing CSV files, you must supply the reader/writer with some preferences.
*
* Please note: the end of line symbols are only used for writing.
*
*
* Predefined configurations
*
* Constant
* Quote character
* Delimiter character
* End of line symbols
*
*
* STANDARD_PREFERENCE",\r\n
*
* EXCEL_PREFERENCE",\n
*
* EXCEL_NORTH_EUROPE_PREFERENCE";\n
*
* TAB_PREFERENCE"\t\n
*
*
*
* By default, spaces surrounding an unquoted cell are treated as part of the data. In versions of Super CSV prior to
* 2.0.0 this wasn't the case, and any surrounding spaces that weren't within quotes were ignored when reading (and
* quotes were automatically added to Strings containing surrounding spaces when writing).
*
*
* If you wish enable this functionality again, then you can create a CsvPreference with the
* surroundingSpacesNeedQuotes flag set to true (the default is false). This means that surrounding spaces
* without quotes will be trimmed when reading, and quotes will automatically be added for Strings containing
* surrounding spaces when writing.
*
*
* You can apply the surroundingSpacesNeedQuotes property to an existing preference as follows:
*
*
* {@code private static final CsvPreference STANDARD_SURROUNDING_SPACES_NEED_QUOTES = new CsvPreference.Builder(CsvPreference.STANDARD_PREFERENCE).surroundingSpacesNeedQuotes(true).build();}
*
*
* You can also create your own preferences. For example if your file was pipe-delimited, you could use the following:
*
*
* {@code private static final CsvPreference PIPE_DELIMITED = new CsvPreference.Builder('"', '|', "\n").build();}
*
* Other preferences incude:
*
* - using a custom {@link CsvEncoder} when writing CSV (if you want complete control over how the CSV is encoded)
* - using a custom {@link QuoteMode} when writing CSV (if you want to enable quotes when they're not normally
* required). You can use the existing {@link org.supercsv.quote.AlwaysQuoteMode AlwaysQuoteMode},
* {@link org.supercsv.quote.ColumnQuoteMode ColumnQuoteMode}, or supply your own.
* - using a custom {@link CommentMatcher} to skip comments when reading CSV. You can use the existing
* {@link org.supercsv.comment.CommentStartsWith CommentStartsWith}, {@link org.supercsv.comment.CommentMatches
* CommentMatches}, or supply your own.
*
*
* @author Kasper B. Graversen
* @author James Bassett
*/
public final class CsvPreference {
/**
* Ready to use configuration that should cover 99% of all usages.
*/
public static final CsvPreference STANDARD_PREFERENCE = new CsvPreference.Builder('"', ',', "\r\n").build();
/**
* Ready to use configuration for Windows Excel exported CSV files.
*/
public static final CsvPreference EXCEL_PREFERENCE = new CsvPreference.Builder('"', ',', "\n").build();
/**
* Ready to use configuration for north European excel CSV files (columns are separated by ";" instead of ",")
*/
public static final CsvPreference EXCEL_NORTH_EUROPE_PREFERENCE = new CsvPreference.Builder('"', ';', "\n").build();
/**
* Ready to use configuration for tab-delimited files.
*/
public static final CsvPreference TAB_PREFERENCE = new CsvPreference.Builder('"', '\t', "\n").build();
private final char quoteChar;
private final int delimiterChar;
private final String endOfLineSymbols;
private final boolean surroundingSpacesNeedQuotes;
private final CsvEncoder encoder;
private final QuoteMode quoteMode;
private final CommentMatcher commentMatcher;
/**
* Constructs a new CsvPreference from a Builder.
*/
private CsvPreference(Builder builder) {
this.quoteChar = builder.quoteChar;
this.delimiterChar = builder.delimiterChar;
this.endOfLineSymbols = builder.endOfLineSymbols;
this.surroundingSpacesNeedQuotes = builder.surroundingSpacesNeedQuotes;
this.commentMatcher = builder.commentMatcher;
this.encoder = builder.encoder;
this.quoteMode = builder.quoteMode;
}
/**
* Returns the delimiter character
*
* @return the delimiter character
*/
public int getDelimiterChar() {
return delimiterChar;
}
/**
* Returns the end of line symbols
*
* @return the end of line symbols
*/
public String getEndOfLineSymbols() {
return endOfLineSymbols;
}
/**
* Returns the quote character
*
* @return the quote character
*/
public int getQuoteChar() {
return quoteChar;
}
/**
* Returns the surroundingSpacesNeedQuotes flag.
*
* @return the surroundingSpacesNeedQuotes flag
*/
public boolean isSurroundingSpacesNeedQuotes() {
return surroundingSpacesNeedQuotes;
}
/**
* Returns the CSV encoder.
*
* @return the CSV encoder
*/
public CsvEncoder getEncoder() {
return encoder;
}
/**
* Returns the quote mode.
*
* @return the quote mode
*/
public QuoteMode getQuoteMode() {
return quoteMode;
}
/**
* Returns the comment matcher.
*
* @return the comment matcher
*/
public CommentMatcher getCommentMatcher() {
return commentMatcher;
}
/**
* Builds immutable CsvPreference instances. The builder pattern allows for additional preferences to be
* added in the future.
*/
public static class Builder {
private final char quoteChar;
private final int delimiterChar;
private final String endOfLineSymbols;
private boolean surroundingSpacesNeedQuotes = false;
private CsvEncoder encoder;
private QuoteMode quoteMode;
private CommentMatcher commentMatcher;
/**
* Constructs a Builder with all of the values from an existing CsvPreference instance. Useful if you
* want to base your preferences off one of the existing CsvPreference constants.
*
* @param preference
* the existing preference
*/
public Builder(final CsvPreference preference) {
this.quoteChar = preference.quoteChar;
this.delimiterChar = preference.delimiterChar;
this.endOfLineSymbols = preference.endOfLineSymbols;
this.surroundingSpacesNeedQuotes = preference.surroundingSpacesNeedQuotes;
this.encoder = preference.encoder;
this.quoteMode = preference.quoteMode;
this.commentMatcher = preference.commentMatcher;
}
/**
* Constructs a Builder with the mandatory preference values.
*
* @param quoteChar
* matching pairs of this character are used to escape columns containing the delimiter
* @param delimiterChar
* the character separating each column
* @param endOfLineSymbols
* one or more symbols terminating the line, e.g. "\n". Only used for writing.
* @throws IllegalArgumentException
* if quoteChar and delimiterChar are the same character
* @throws NullPointerException
* if endOfLineSymbols is null
*/
public Builder(final char quoteChar, final int delimiterChar, final String endOfLineSymbols) {
if( quoteChar == delimiterChar ) {
throw new IllegalArgumentException(String.format(
"quoteChar and delimiterChar should not be the same character: %c", quoteChar));
} else if( endOfLineSymbols == null ) {
throw new NullPointerException("endOfLineSymbols should not be null");
}
this.quoteChar = quoteChar;
this.delimiterChar = delimiterChar;
this.endOfLineSymbols = endOfLineSymbols;
}
/**
* Flag indicating whether spaces at the beginning or end of a cell should be ignored if they're not surrounded
* by quotes (applicable to both reading and writing CSV). The default is false, as spaces
* "are considered part of a field and should not be ignored" according to RFC 4180.
*
* @since 2.0.0
* @param surroundingSpacesNeedQuotes
* flag indicating whether spaces at the beginning or end of a cell should be ignored if they're not
* surrounded by quotes
* @return the updated Builder
*/
public Builder surroundingSpacesNeedQuotes(final boolean surroundingSpacesNeedQuotes) {
this.surroundingSpacesNeedQuotes = surroundingSpacesNeedQuotes;
return this;
}
/**
* Enables the skipping of comments. You can supply your own comment matcher or use one of the predefined ones:
* {@link org.supercsv.comment.CommentStartsWith CommentStartsWith} or
* {@link org.supercsv.comment.CommentMatches CommentMatches}
*
* @since 2.1.0
* @param commentMatcher
* the comment matcher to use
* @return the updated Builder
* @throws NullPointerException
* if commentMatcher is null
*/
public Builder skipComments(final CommentMatcher commentMatcher) {
if( commentMatcher == null ) {
throw new NullPointerException("commentMatcher should not be null");
}
this.commentMatcher = commentMatcher;
return this;
}
/**
* Uses a custom CsvEncoder to escape CSV for writing.
*
* @since 2.1.0
* @param encoder
* the custom encoder
* @return the updated Builder
* @throws NullPointerException
* if encoder is null
*/
public Builder useEncoder(final CsvEncoder encoder) {
if( encoder == null ) {
throw new NullPointerException("encoder should not be null");
}
this.encoder = encoder;
return this;
}
/**
* Uses a custom QuoteMode to determine if surrounding quotes should be applied when writing (only applicable if
* a column doesn't contain any special characters and wouldn't otherwise be quoted). You can supply your own
* quote mode or use one of the predefined ones: {@link org.supercsv.quote.AlwaysQuoteMode AlwaysQuoteMode} or
* {@link org.supercsv.quote.ColumnQuoteMode ColumnQuoteMode}
*
* @since 2.1.0
* @param quoteMode
* the quote mode
* @return the updated Builder
* @throws NullPointerException
* if quoteMode is null
*/
public Builder useQuoteMode(final QuoteMode quoteMode) {
if( quoteMode == null ) {
throw new NullPointerException("quoteMode should not be null");
}
this.quoteMode = quoteMode;
return this;
}
/**
* Builds the CsvPreference instance.
*
* @return the immutable CsvPreference instance
*/
public CsvPreference build() {
if( encoder == null ) {
encoder = new DefaultCsvEncoder();
}
if( quoteMode == null ) {
quoteMode = new NormalQuoteMode();
}
return new CsvPreference(this);
}
}
}