org.apache.hadoop.fs.shell.PrintableString 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.fs.shell;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
/**
* The {code PrintableString} class converts any string to a printable string
* by replacing non-printable characters with ?.
*
* Categories of Unicode non-printable characters:
*
* - Control characters (Cc)
*
- Formatting Unicode (Cf)
*
- Private use Unicode (Co)
*
- Unassigned Unicode (Cn)
*
- Standalone surrogate (Unfortunately no matching Unicode category)
*
*
* @see Character
* @see The Unicode Consortium
*/
@InterfaceAudience.Public
@InterfaceStability.Evolving
class PrintableString {
private static final char REPLACEMENT_CHAR = '?';
private final String printableString;
PrintableString(String rawString) {
StringBuilder stringBuilder = new StringBuilder(rawString.length());
for (int offset = 0; offset < rawString.length();) {
int codePoint = rawString.codePointAt(offset);
offset += Character.charCount(codePoint);
switch (Character.getType(codePoint)) {
case Character.CONTROL: // Cc
case Character.FORMAT: // Cf
case Character.PRIVATE_USE: // Co
case Character.SURROGATE: // Cs
case Character.UNASSIGNED: // Cn
stringBuilder.append(REPLACEMENT_CHAR);
break;
default:
stringBuilder.append(Character.toChars(codePoint));
break;
}
}
printableString = stringBuilder.toString();
}
public String toString() {
return printableString;
}
}