/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.apache.hive.service.cli;
/**
* CLIServiceUtils.
*
*/
public class CLIServiceUtils {
private static final char SEARCH_STRING_ESCAPE = '\\';
/**
* Convert a SQL search pattern into an equivalent Java Regex.
*
* @param pattern input which may contain '%' or '_' wildcard characters, or
* these characters escaped using {@link #getSearchStringEscape()}.
* @return replace %/_ with regex search characters, also handle escaped
* characters.
*/
public static String patternToRegex(String pattern) {
if (pattern == null) {
return ".*";
} else {
StringBuilder result = new StringBuilder(pattern.length());
boolean escaped = false;
for (int i = 0, len = pattern.length(); i < len; i++) {
char c = pattern.charAt(i);
if (escaped) {
if (c != SEARCH_STRING_ESCAPE) {
escaped = false;
}
result.append(c);
} else {
if (c == SEARCH_STRING_ESCAPE) {
escaped = true;
continue;
} else if (c == '%') {
result.append(".*");
} else if (c == '_') {
result.append('.');
} else {
result.append(Character.toLowerCase(c));
}
}
}
return result.toString();
}
}
}