com.clickhouse.jdbc.parser.ClickHouseSqlUtils Maven / Gradle / Ivy
package com.clickhouse.jdbc.parser;
public final class ClickHouseSqlUtils {
public static boolean isQuote(char ch) {
return ch == '"' || ch == '\'' || ch == '`';
}
/**
* Escape quotes in given string.
*
* @param str string
* @param quote quote to escape
* @return escaped string
*/
public static String escape(String str, char quote) {
if (str == null) {
return str;
}
int len = str.length();
StringBuilder sb = new StringBuilder(len + 10).append(quote);
for (int i = 0; i < len; i++) {
char ch = str.charAt(i);
if (ch == quote || ch == '\\') {
sb.append('\\');
}
sb.append(ch);
}
return sb.append(quote).toString();
}
/**
* Unescape quoted string.
*
* @param str quoted string
* @return unescaped string
*/
public static String unescape(String str) {
if (str == null || str.isEmpty()) {
return str;
}
int len = str.length();
char quote = str.charAt(0);
if (!isQuote(quote) || quote != str.charAt(len - 1)) { // not a quoted string
return str;
}
StringBuilder sb = new StringBuilder(len = len - 1);
for (int i = 1; i < len; i++) {
char ch = str.charAt(i);
if (++i >= len) {
sb.append(ch);
} else {
char nextChar = str.charAt(i);
if (ch == '\\' || (ch == quote && nextChar == quote)) {
sb.append(nextChar);
} else {
sb.append(ch);
i--;
}
}
}
return sb.toString();
}
private ClickHouseSqlUtils() {
}
}