org.apache.hadoop.hive.common.cli.EscapeCRLFHelper Maven / Gradle / Ivy
/*
* 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.hadoop.hive.common.cli;
public class EscapeCRLFHelper {
private static final char CARRIAGE_RETURN = '\r';
private static final char LINE_FEED = '\n';
public EscapeCRLFHelper() {
}
/*
* Substitute for any carriage return or line feed characters in line with the escaped
* 2-character sequences \r or \n.
*
* @param line the string for the CRLF substitution.
* @return If there were no replacements, then just return line. Otherwise, a new String with
* escaped CRLF.
*/
public static String escapeCRLF(String line) {
StringBuilder sb = null;
int lastNonCRLFIndex = 0;
int index = 0;
final int length = line.length();
while (index < length) {
char ch = line.charAt(index);
if (ch == CARRIAGE_RETURN || ch == LINE_FEED) {
if (sb == null) {
// We defer allocation until we really need it since in the common case there is
// no CRLF substitution.
sb = new StringBuilder();
}
if (lastNonCRLFIndex < index) {
// Copy an intervening non-CRLF characters up to but not including current 'index'.
sb.append(line.substring(lastNonCRLFIndex, index));
}
lastNonCRLFIndex = ++index;
if (ch == CARRIAGE_RETURN) {
sb.append("\\r");
} else {
sb.append("\\n");
}
} else {
index++;
}
}
if (sb == null) {
// No CRLF substitution -- return original line.
return line;
} else {
if (lastNonCRLFIndex < index) {
// Copy an intervening non-CRLF characters up to but not including current 'index'.
sb.append(line.substring(lastNonCRLFIndex, index));
}
return sb.toString();
}
}
}