Java/File Input Output/CharSequence
A contiguous range of characters, optionally negated.
<source lang="java">
/*
* 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. */
import java.io.Serializable; /**
*A contiguous range of characters, optionally negated.
**
Instances are immutable.
* * @author Stephen Colebourne * @author Chris Feldhacker * @author Gary Gregory * @since 1.0 * @version $Id: CharRange.java 471626 2006-11-06 04:02:09Z bayard $ */
public final class CharRange implements Serializable {
/**
* Required for serialization support. Lang version 2.0.
*
* @see java.io.Serializable
*/
private static final long serialVersionUID = 8270183163158333422L;
/** The first character, inclusive, in the range. */
private final char start;
/** The last character, inclusive, in the range. */
private final char end;
/** True if the range is everything except the characters specified. */
private final boolean negated;
/** Cached toString. */
private transient String iToString;
//-----------------------------------------------------------------------
/**
* Constructs a CharRange over a single character.
*
* @param ch only character in this range
*/
public CharRange(char ch) {
this(ch, ch, false);
}
/**
* Constructs a CharRange over a single character,
* optionally negating the range.
**
A negated range includes everything except the specified char.
*
* @param ch only character in this range
* @param negated true to express everything except the range
*/
public CharRange(char ch, boolean negated) {
this(ch, ch, negated);
}
/**
* Constructs a CharRange over a set of characters.
*
* @param start first character, inclusive, in this range
* @param end last character, inclusive, in this range
*/
public CharRange(char start, char end) {
this(start, end, false);
}
/**
* Constructs a CharRange over a set of characters,
* optionally negating the range.
**
A negated range includes everything except that defined by the * start and end characters.
**
If start and end are in the wrong order, they are reversed.
* Thus a-e is the same as e-a.
*
* @param start first character, inclusive, in this range
* @param end last character, inclusive, in this range
* @param negated true to express everything except the range
*/
public CharRange(char start, char end, boolean negated) {
super();
if (start > end) {
char temp = start;
start = end;
end = temp;
}
this.start = start;
this.end = end;
this.negated = negated;
}
// Accessors
//-----------------------------------------------------------------------
/**
* Gets the start character for this character range.
*
* @return the start char (inclusive)
*/
public char getStart() {
return this.start;
}
/**
* Gets the end character for this character range.
*
* @return the end char (inclusive)
*/
public char getEnd() {
return this.end;
}
/**
* Is this CharRange negated.
**
A negated range includes everything except that defined by the * start and end characters.
*
* @return true is negated
*/
public boolean isNegated() {
return negated;
}
// Contains
//-----------------------------------------------------------------------
/**
* Is the character specified contained in this range.
*
* @param ch the character to check
* @return true if this range contains the input character
*/
public boolean contains(char ch) {
return (ch >= start && ch <= end) != negated;
}
/**
* Are all the characters of the passed in range contained in * this range.
*
* @param range the range to check against
* @return true if this range entirely contains the input range
* @throws IllegalArgumentException if null input
*/
public boolean contains(CharRange range) {
if (range == null) {
throw new IllegalArgumentException("The Range must not be null");
}
if (negated) {
if (range.negated) {
return start >= range.start && end <= range.end;
} else {
return range.end < start || range.start > end;
}
} else {
if (range.negated) {
return start == 0 && end == Character.MAX_VALUE;
} else {
return start <= range.start && end >= range.end;
}
}
}
// Basics
//-----------------------------------------------------------------------
/**
* Compares two CharRange objects, returning true if they represent * exactly the same range of characters defined in the same way.
*
* @param obj the object to compare to
* @return true if equal
*/
public boolean equals(Object obj) {
if (obj == this) {
return true;
}
if (obj instanceof CharRange == false) {
return false;
}
CharRange other = (CharRange) obj;
return start == other.start && end == other.end && negated == other.negated;
}
/**
* Gets a hashCode compatible with the equals method.
*
* @return a suitable hashCode
*/
public int hashCode() {
return 83 + start + 7 * end + (negated ? 1 : 0);
}
/**
* Gets a string representation of the character range.
*
* @return string representation of this range
*/
public String toString() {
if (iToString == null) {
StringBuffer buf = new StringBuffer(4);
if (isNegated()) {
buf.append("^");
}
buf.append(start);
if (start != end) {
buf.append("-");
buf.append(end);
}
iToString = buf.toString();
}
return iToString;
}
}
</source>
Arrays.copyOf CharSequence
<source lang="java">
import java.util.Arrays; public class Copy {
public static void main(String[] args) {
String[] sa = { "First", "Second", "Third" };
CharSequence[] csa;
csa = Arrays.copyOf(sa, sa.length, CharSequence[].class);
for (int i = 0; i < csa.length; i++)
System.out.println(csa[i].length());
}
}
</source>
