com.opencsv.CSVParser Maven / Gradle / Ivy
package com.opencsv;
import static com.opencsv.CSVReaderNullFieldIndicator.NEITHER;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
/**
* A very simple CSV parser released under a commercial-friendly license.
* This just implements splitting a single line into fields.
*
* @author Glen Smith
* @author Rainer Pruy
*/
public class CSVParser {
/**
* The default separator to use if none is supplied to the constructor.
*/
public static final char DEFAULT_SEPARATOR = ',';
/**
* The average size of a line read by openCSV (used for setting the size of StringBuilders).
*/
public static final int INITIAL_READ_SIZE = 1024;
/**
* In most cases we know the size of the line we want to read. In that case we will set the initial read
* to that plus an buffer size.
*/
public static final int READ_BUFFER_SIZE = 128;
/**
* The default quote character to use if none is supplied to the
* constructor.
*/
public static final char DEFAULT_QUOTE_CHARACTER = '"';
/**
* The default escape character to use if none is supplied to the
* constructor.
*/
public static final char DEFAULT_ESCAPE_CHARACTER = '\\';
/**
* The default strict quote behavior to use if none is supplied to the
* constructor.
*/
public static final boolean DEFAULT_STRICT_QUOTES = false;
/**
* The default leading whitespace behavior to use if none is supplied to the
* constructor.
*/
public static final boolean DEFAULT_IGNORE_LEADING_WHITESPACE = true;
/**
* If the quote character is set to null then there is no quote character.
*/
public static final boolean DEFAULT_IGNORE_QUOTATIONS = false;
/**
* This is the "null" character - if a value is set to this then it is ignored.
*/
public static final char NULL_CHARACTER = '\0';
/**
* Denotes what field contents will cause the parser to return null: EMPTY_SEPARATORS, EMPTY_QUOTES, BOTH, NEITHER (default)
*/
public static final CSVReaderNullFieldIndicator DEFAULT_NULL_FIELD_INDICATOR = NEITHER;
/**
* This is the character that the CSVParser will treat as the separator.
*/
private final char separator;
/**
* This is the character that the CSVParser will treat as the quotation character.
*/
private final char quotechar;
/**
* This is the character that the CSVParser will treat as the escape character.
*/
private final char escape;
/**
* Determines if the field is between quotes (true) or between separators (false).
*/
private final boolean strictQuotes;
/**
* Ignore any leading white space at the start of the field.
*/
private final boolean ignoreLeadingWhiteSpace;
/**
* Skip over quotation characters when parsing.
*/
private final boolean ignoreQuotations;
private final CSVReaderNullFieldIndicator nullFieldIndicator;
private String pending;
private boolean inField = false;
/**
* Constructs CSVParser using a comma for the separator.
*/
public CSVParser() {
this(DEFAULT_SEPARATOR, DEFAULT_QUOTE_CHARACTER, DEFAULT_ESCAPE_CHARACTER);
}
/**
* Constructs CSVParser with supplied separator.
*
* @param separator the delimiter to use for separating entries.
*/
public CSVParser(char separator) {
this(separator, DEFAULT_QUOTE_CHARACTER, DEFAULT_ESCAPE_CHARACTER);
}
/**
* Constructs CSVParser with supplied separator and quote char.
*
* @param separator the delimiter to use for separating entries
* @param quotechar the character to use for quoted elements
*/
public CSVParser(char separator, char quotechar) {
this(separator, quotechar, DEFAULT_ESCAPE_CHARACTER);
}
/**
* Constructs CSVReader with supplied separator and quote char.
*
* @param separator the delimiter to use for separating entries
* @param quotechar the character to use for quoted elements
* @param escape the character to use for escaping a separator or quote
*/
public CSVParser(char separator, char quotechar, char escape) {
this(separator, quotechar, escape, DEFAULT_STRICT_QUOTES);
}
/**
* Constructs CSVParser with supplied separator and quote char.
* Allows setting the "strict quotes" flag
*
* @param separator the delimiter to use for separating entries
* @param quotechar the character to use for quoted elements
* @param escape the character to use for escaping a separator or quote
* @param strictQuotes if true, characters outside the quotes are ignored
*/
public CSVParser(char separator, char quotechar, char escape, boolean strictQuotes) {
this(separator, quotechar, escape, strictQuotes, DEFAULT_IGNORE_LEADING_WHITESPACE);
}
/**
* Constructs CSVParser with supplied separator and quote char.
* Allows setting the "strict quotes" and "ignore leading whitespace" flags
*
* @param separator the delimiter to use for separating entries
* @param quotechar the character to use for quoted elements
* @param escape the character to use for escaping a separator or quote
* @param strictQuotes if true, characters outside the quotes are ignored
* @param ignoreLeadingWhiteSpace if true, white space in front of a quote in a field is ignored
*/
public CSVParser(char separator, char quotechar, char escape, boolean strictQuotes, boolean ignoreLeadingWhiteSpace) {
this(separator, quotechar, escape, strictQuotes, ignoreLeadingWhiteSpace, DEFAULT_IGNORE_QUOTATIONS);
}
/**
* Constructs CSVParser with supplied separator and quote char.
* Allows setting the "strict quotes" and "ignore leading whitespace" flags
*
* @param separator the delimiter to use for separating entries
* @param quotechar the character to use for quoted elements
* @param escape the character to use for escaping a separator or quote
* @param strictQuotes if true, characters outside the quotes are ignored
* @param ignoreLeadingWhiteSpace if true, white space in front of a quote in a field is ignored
* @param ignoreQuotations if true, treat quotations like any other character.
*/
public CSVParser(char separator, char quotechar, char escape, boolean strictQuotes, boolean ignoreLeadingWhiteSpace,
boolean ignoreQuotations) {
this(separator, quotechar, escape, strictQuotes, ignoreLeadingWhiteSpace, ignoreQuotations, DEFAULT_NULL_FIELD_INDICATOR);
}
/**
* Constructs CSVParser with supplied separator and quote char.
* Allows setting the "strict quotes" and "ignore leading whitespace" flags
*
* @param separator the delimiter to use for separating entries
* @param quotechar the character to use for quoted elements
* @param escape the character to use for escaping a separator or quote
* @param strictQuotes if true, characters outside the quotes are ignored
* @param ignoreLeadingWhiteSpace if true, white space in front of a quote in a field is ignored
* @param ignoreQuotations if true, treat quotations like any other character.
* @param nullFieldIndicator which field content will be returned as null: EMPTY_SEPARATORS, EMPTY_QUOTES,
* BOTH, NEITHER (default)
*/
CSVParser(char separator, char quotechar, char escape, boolean strictQuotes, boolean ignoreLeadingWhiteSpace,
boolean ignoreQuotations, CSVReaderNullFieldIndicator nullFieldIndicator) {
if (anyCharactersAreTheSame(separator, quotechar, escape)) {
throw new UnsupportedOperationException("The separator, quote, and escape characters must be different!");
}
if (separator == NULL_CHARACTER) {
throw new UnsupportedOperationException("The separator character must be defined!");
}
this.separator = separator;
this.quotechar = quotechar;
this.escape = escape;
this.strictQuotes = strictQuotes;
this.ignoreLeadingWhiteSpace = ignoreLeadingWhiteSpace;
this.ignoreQuotations = ignoreQuotations;
this.nullFieldIndicator = nullFieldIndicator;
}
/**
* @return The default separator for this parser.
*/
public char getSeparator() {
return separator;
}
/**
* @return The default quotation character for this parser.
*/
public char getQuotechar() {
return quotechar;
}
/**
* @return The default escape character for this parser.
*/
public char getEscape() {
return escape;
}
/**
* @return The default strictQuotes setting for this parser.
*/
public boolean isStrictQuotes() {
return strictQuotes;
}
/**
* @return The default ignoreLeadingWhiteSpace setting for this parser.
*/
public boolean isIgnoreLeadingWhiteSpace() {
return ignoreLeadingWhiteSpace;
}
/**
* @return the default ignoreQuotation setting for this parser.
*/
public boolean isIgnoreQuotations() {
return ignoreQuotations;
}
/**
* checks to see if any two of the three characters are the same. This is because in openCSV the
* separator, quote, and escape characters must the different.
*
* @param separator the defined separator character
* @param quotechar the defined quotation cahracter
* @param escape the defined escape character
* @return true if any two of the three are the same.
*/
private boolean anyCharactersAreTheSame(char separator, char quotechar, char escape) {
return isSameCharacter(separator, quotechar) || isSameCharacter(separator, escape) || isSameCharacter(quotechar, escape);
}
/**
* checks that the two characters are the same and are not the defined NULL_CHARACTER.
* @param c1 first character
* @param c2 second character
* @return true if both characters are the same and are not the defined NULL_CHARACTER
*/
private boolean isSameCharacter(char c1, char c2) {
return c1 != NULL_CHARACTER && c1 == c2;
}
/**
* @return true if something was left over from last call(s)
*/
public boolean isPending() {
return pending != null;
}
/**
* Parses an incoming String and returns an array of elements. This method is used when the
* data spans multiple lines.
*
* @param nextLine current line to be processed
* @return the comma-tokenized list of elements, or null if nextLine is null
* @throws IOException if bad things happen during the read
*/
public String[] parseLineMulti(String nextLine) throws IOException {
return parseLine(nextLine, true);
}
/**
* Parses an incoming String and returns an array of elements. This method is used when all data is contained
* in a single line.
*
* @param nextLine Line to be parsed.
* @return the comma-tokenized list of elements, or null if nextLine is null
* @throws IOException if bad things happen during the read
*/
public String[] parseLine(String nextLine) throws IOException {
return parseLine(nextLine, false);
}
/**
* Parses an incoming String and returns an array of elements.
*
* @param nextLine the string to parse
* @param multi Does it take multiple lines to form a single record.
* @return the comma-tokenized list of elements, or null if nextLine is null
* @throws IOException if bad things happen during the read
*/
private String[] parseLine(String nextLine, boolean multi) throws IOException {
if (!multi && pending != null) {
pending = null;
}
if (nextLine == null) {
if (pending != null) {
String s = pending;
pending = null;
return new String[]{s};
} else {
return null;
}
}
List tokensOnThisLine = new ArrayList();
StringBuilder sb = new StringBuilder(nextLine.length() + READ_BUFFER_SIZE);
boolean inQuotes = false;
boolean fromQuotedField = false;
if (pending != null) {
sb.append(pending);
pending = null;
inQuotes = !this.ignoreQuotations;//true;
}
for (int i = 0; i < nextLine.length(); i++) {
char c = nextLine.charAt(i);
if (c == this.escape) {
if (isNextCharacterEscapable(nextLine, inQuotes(inQuotes), i)) {
i = appendNextCharacterAndAdvanceLoop(nextLine, sb, i);
}
} else if (c == quotechar) {
if (isNextCharacterEscapedQuote(nextLine, inQuotes(inQuotes), i)) {
i = appendNextCharacterAndAdvanceLoop(nextLine, sb, i);
} else {
inQuotes = !inQuotes;
if (atStartOfField(sb)) {
fromQuotedField = true;
}
// the tricky case of an embedded quote in the middle: a,bc"d"ef,g
if (!strictQuotes) {
if (i > 2 //not on the beginning of the line
&& nextLine.charAt(i - 1) != this.separator //not at the beginning of an escape sequence
&& nextLine.length() > (i + 1) &&
nextLine.charAt(i + 1) != this.separator //not at the end of an escape sequence
) {
if (ignoreLeadingWhiteSpace && sb.length() > 0 && isAllWhiteSpace(sb)) {
sb.setLength(0);
} else {
sb.append(c);
}
}
}
}
inField = !inField;
} else if (c == separator && !(inQuotes && !ignoreQuotations)) {
tokensOnThisLine.add(convertEmptyToNullIfNeeded(sb.toString(), fromQuotedField));
fromQuotedField = false;
sb.setLength(0);
inField = false;
} else {
if (!strictQuotes || (inQuotes && !ignoreQuotations)) {
sb.append(c);
inField = true;
fromQuotedField = true;
}
}
}
// line is done - check status
if ((inQuotes && !ignoreQuotations)) {
if (multi) {
// continuing a quoted section, re-append newline
sb.append('\n');
pending = sb.toString();
sb = null; // this partial content is not to be added to field list yet
} else {
throw new IOException("Un-terminated quoted field at end of CSV line");
}
if (inField) {
fromQuotedField = true;
}
} else {
inField = false;
}
if (sb != null) {
tokensOnThisLine.add(convertEmptyToNullIfNeeded(sb.toString(), fromQuotedField));
fromQuotedField = false;
}
return tokensOnThisLine.toArray(new String[tokensOnThisLine.size()]);
}
private boolean atStartOfField(StringBuilder sb) {
return sb.length() == 0;
}
private String convertEmptyToNullIfNeeded(String s, boolean fromQuotedField) {
if (s.isEmpty() && shouldConvertEmptyToNull(fromQuotedField)) {
return null;
}
return s;
}
private boolean shouldConvertEmptyToNull(boolean fromQuotedField) {
switch (nullFieldIndicator) {
case BOTH:
return true;
case EMPTY_SEPARATORS:
return !fromQuotedField;
case EMPTY_QUOTES:
return fromQuotedField;
default:
return false;
}
}
/**
* Appends the next character in the line to the stringbuffer.
*
* @param line - line to process
* @param sb - contains the processed character
* @param i - current position in the line.
* @return new position in the line.
*/
private int appendNextCharacterAndAdvanceLoop(String line, StringBuilder sb, int i) {
sb.append(line.charAt(i + 1));
i++;
return i;
}
/**
* Determines if we can process as if we were in quotes.
*
* @param inQuotes - are we currently in quotes.
* @return - true if we should process as if we are inside quotes.
*/
private boolean inQuotes(boolean inQuotes) {
return (inQuotes && !ignoreQuotations) || inField;
}
/**
* Checks to see if the character after the index is a quotation character.
*
* precondition: the current character is a quote or an escape
*
* @param nextLine the current line
* @param inQuotes true if the current context is quoted
* @param i current index in line
* @return true if the following character is a quote
*/
private boolean isNextCharacterEscapedQuote(String nextLine, boolean inQuotes, int i) {
return inQuotes // we are in quotes, therefore there can be escaped quotes in here.
&& nextLine.length() > (i + 1) // there is indeed another character to check.
&& isCharacterQuoteCharacter(nextLine.charAt(i + 1));
}
/**
* Checks to see if the passed in character is the defined quotation character.
*
* @param c source character
* @return true if c is the defined quotation character
*/
private boolean isCharacterQuoteCharacter(char c) {
return c == quotechar;
}
/**
* checks to see if the character is the defined escape character.
*
* @param c source character
* @return true if the character is the defined escape character
*/
private boolean isCharacterEscapeCharacter(char c) {
return c == escape;
}
/**
* Checks to see if the character passed in could be escapable. Escapable characters for openCSV are the
* quotation character or the escape character.
*
* @param c source character
* @return true if the character could be escapable.
*/
private boolean isCharacterEscapable(char c) {
return isCharacterQuoteCharacter(c) || isCharacterEscapeCharacter(c);
}
/**
* Checks to see if the character after the current index in a String is an escapable character.
* Meaning the next character is either a quotation character or the escape char and you are inside
* quotes.
*
* precondition: the current character is an escape
*
* @param nextLine the current line
* @param inQuotes true if the current context is quoted
* @param i current index in line
* @return true if the following character is a quote
*/
protected boolean isNextCharacterEscapable(String nextLine, boolean inQuotes, int i) {
return inQuotes // we are in quotes, therefore there can be escaped quotes in here.
&& nextLine.length() > (i + 1) // there is indeed another character to check.
&& isCharacterEscapable(nextLine.charAt(i + 1));
}
/**
* Checks if every element is the character sequence is whitespace.
*
* precondition: sb.length() is greater than 0
*
* @param sb A sequence of characters to examine
* @return true if every character in the sequence is whitespace
*/
protected boolean isAllWhiteSpace(CharSequence sb) {
for( int i=0; i © 2015 - 2025 Weber Informatics LLC | Privacy Policy