com.opencsv.AbstractCSVParser Maven / Gradle / Ivy
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package com.opencsv;
import com.opencsv.enums.CSVReaderNullFieldIndicator;
import org.apache.commons.lang3.StringUtils;
import java.io.IOException;
import java.util.regex.Pattern;
import java.util.stream.Collectors;
import java.util.stream.Stream;
/**
* The purpose of the AbstractCSVParser is to consolidate the duplicate code amongst the
* parsers.
*/
public abstract class AbstractCSVParser implements ICSVParser {
/**
* This is needed by the split command in case the separator character is a regex special character.
*/
protected static final Pattern SPECIAL_REGEX_CHARS = Pattern.compile("[{}()\\[\\].+*?^$\\\\|]");
/**
* Empty StringBuilder
*/
protected static final StringBuilder EMPTY_STRINGBUILDER = new StringBuilder("");
/**
* This is the character that the CSVParser will treat as the separator.
*/
protected final char separator;
/**
* This is the separator in Stirng form to reduce the number of calls to toString.
*/
protected final String separatorAsString;
/**
* This is the character that the CSVParser will treat as the quotation character.
*/
protected final char quotechar;
/**
* This is the quotechar in String form to reduce the number of calls to toString.
*/
protected final String quotecharAsString;
/**
* This is quotecharAsString+quotecharAsString - used in replaceAll to reduce the number of strings being created.
*/
protected final String quoteDoubledAsString;
/**
* pattern created to match quotechars - optimizaion of the String.replaceAll.
*/
protected final Pattern quoteMatcherPattern;
/**
* Determines the handling of null fields.
*
* @see CSVReaderNullFieldIndicator
*/
protected final CSVReaderNullFieldIndicator nullFieldIndicator;
/**
* Value to be appended to string to process.
*/
protected String pending;
/**
* Common constructor.
*
* @param separator The delimiter to use for separating entries
* @param quotechar The character to use for quoted elements
* @param nullFieldIndicator Indicate what should be considered null
*/
public AbstractCSVParser(char separator, char quotechar, CSVReaderNullFieldIndicator nullFieldIndicator) {
this.separator = separator;
this.separatorAsString = SPECIAL_REGEX_CHARS.matcher(Character.toString(separator)).replaceAll("\\\\$0");
this.quotechar = quotechar;
this.quotecharAsString = Character.toString(quotechar);
this.quoteDoubledAsString = this.quotecharAsString + this.quotecharAsString;
this.quoteMatcherPattern = Pattern.compile(quotecharAsString);
this.nullFieldIndicator = nullFieldIndicator;
}
@Override
public char getSeparator() {
return separator;
}
/**
* @return String version of separator to reduce number of calls to toString.
*/
public String getSeparatorAsString() {
return separatorAsString;
}
@Override
public char getQuotechar() {
return quotechar;
}
/**
* @return String version of quotechar to reduce the number of calls to toString.
*/
public String getQuotecharAsString() {
return quotecharAsString;
}
@Override
public boolean isPending() {
return pending != null;
}
@Override
public String[] parseLineMulti(String nextLine) throws IOException {
return parseLine(nextLine, true);
}
@Override
public String[] parseLine(String nextLine) throws IOException {
return parseLine(nextLine, false);
}
@Override
public String parseToLine(String[] values, boolean applyQuotesToAll) {
return Stream.of(values)
.map(v -> convertToCsvValue(v, applyQuotesToAll))
.collect(Collectors.joining(getSeparatorAsString()));
}
@Override
public void parseToLine(String[] values, boolean applyQuotesToAll, Appendable appendable) throws IOException {
boolean first = true;
for (String value : values) {
if (!first) {
appendable.append(getSeparator());
} else {
first = false;
}
convertToCsvValue(value, applyQuotesToAll, appendable);
}
}
/**
* Used when reverse parsing an array of strings to a single string. Handles the application of quotes around
* the string and handling any quotes within the string.
*
* @param value String to be converted
* @param applyQuotestoAll All values should be surrounded with quotes
* @return String that will go into the CSV string
*/
protected abstract String convertToCsvValue(String value, boolean applyQuotestoAll);
/**
* Used when reverse parsing an array of strings to a single string. Handles the application of quotes around
* the string and handling any quotes within the string.
*
* NOTE: as of 5.7.2 most objects will be inheriting a solution that calls the existing convertToCsvValue and thus
* will not receive much benefit.
*
* @param value String to be converted
* @param applyQuotesToAll All values should be surrounded with quotes
* @param appendable Appendable object that the converted values are added to.
*/
protected void convertToCsvValue(String value, boolean applyQuotesToAll, Appendable appendable) throws IOException {
appendable.append(convertToCsvValue(value, applyQuotesToAll));
}
/**
* Used by reverse parsing to determine if a value should be surrounded by quote characters.
*
* @param value String to be tested
* @param forceSurround If the value is not {@code null} it will be surrounded with quotes
* @return True if the string should be surrounded with quotes, false otherwise
*/
protected boolean isSurroundWithQuotes(String value, boolean forceSurround) {
if (value == null) {
return nullFieldIndicator.equals(CSVReaderNullFieldIndicator.EMPTY_QUOTES);
} else if (value.isEmpty() && nullFieldIndicator.equals(CSVReaderNullFieldIndicator.EMPTY_SEPARATORS)) {
return true;
}
return forceSurround || value.contains(getSeparatorAsString()) || value.contains(NEWLINE);
}
/**
* Parses an incoming {@link java.lang.String} and returns an array of elements.
*
* @param nextLine The string to parse
* @param multi Whether it takes multiple lines to form a single record
* @return The list of elements, or {@code null} if {@code nextLine} is {@code null}
* @throws IOException If bad things happen during the read
*/
protected abstract String[] parseLine(String nextLine, boolean multi) throws IOException;
@Override
public CSVReaderNullFieldIndicator nullFieldIndicator() {
return nullFieldIndicator;
}
@Override
public String getPendingText() {
return StringUtils.defaultString(pending);
}
}