com.facebook.presto.hive.$internal.jodd.util.CsvUtil Maven / Gradle / Ivy
// Copyright (c) 2003-2014, Jodd Team (com.facebook.presto.hive.$internal.jodd.org). All Rights Reserved.
package com.facebook.presto.hive.$internal.jodd.util;
import java.util.ArrayList;
import java.util.List;
/**
* Helps with CSV strings.
* See: http://en.wikipedia.org/wiki/Comma-separated_values
*/
public class CsvUtil {
protected static final char FIELD_SEPARATOR = ',';
protected static final char FIELD_QUOTE = '"';
protected static final String DOUBLE_QUOTE = "\"\"";
protected static final String SPECIAL_CHARS = "\r\n";
/**
* Parse fields as csv string,
*/
public static String toCsvString(Object... elements) {
StringBuilder line = new StringBuilder();
int last = elements.length -1;
for (int i = 0; i < elements.length; i++) {
if (elements[i] == null) {
if (i != last) {
line.append(FIELD_SEPARATOR);
}
continue;
}
String field = elements[i].toString();
// check for special cases
int ndx = field.indexOf(FIELD_SEPARATOR);
if (ndx == -1) {
ndx = field.indexOf(FIELD_QUOTE);
}
if (ndx == -1) {
if (field.startsWith(StringPool.SPACE) || field.endsWith(StringPool.SPACE)) {
ndx = 1;
}
}
if (ndx == -1) {
ndx = StringUtil.indexOfChars(field, SPECIAL_CHARS);
}
// add field
if (ndx != -1) {
line.append(FIELD_QUOTE);
}
field = StringUtil.replace(field, StringPool.QUOTE, DOUBLE_QUOTE);
line.append(field);
if (ndx != -1) {
line.append(FIELD_QUOTE);
}
// last
if (i != last) {
line.append(FIELD_SEPARATOR);
}
}
return line.toString();
}
/**
* Converts CSV line to string array.
*/
public static String[] toStringArray(String line) {
List row = new ArrayList();
boolean inQuotedField = false;
int fieldStart = 0;
final int len = line.length();
for (int i = 0; i < len; i++) {
char c = line.charAt(i);
if (c == FIELD_SEPARATOR) {
if (!inQuotedField) { // ignore we are quoting
addField(row, line, fieldStart, i, inQuotedField);
fieldStart = i + 1;
}
} else if (c == FIELD_QUOTE) {
if (inQuotedField) {
if (i + 1 == len || line.charAt(i + 1) == FIELD_SEPARATOR) { // we are already quoting - peek to see if this is the end of the field
addField(row, line, fieldStart, i, inQuotedField);
fieldStart = i + 2;
i++; // and skip the comma
inQuotedField = false;
}
} else if (fieldStart == i) {
inQuotedField = true; // this is a beginning of a quote
fieldStart++; // move field start
}
}
}
// add last field - but only if string was not empty
if (len > 0 && fieldStart <= len) {
addField(row, line, fieldStart, len, inQuotedField);
}
return row.toArray(new String[row.size()]);
}
private static void addField(List row, String line, int startIndex, int endIndex, boolean inQuoted) {
String field = line.substring(startIndex, endIndex);
if (inQuoted) {
field = StringUtil.replace(field, DOUBLE_QUOTE, "\"");
}
row.add(field);
}
}