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Java 1.8+ Library with tons of utility classes required in all projects
/*
* Copyright (C) 2014-2022 Philip Helger (www.helger.com)
* philip[at]helger[dot]com
*
* Licensed 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 com.helger.commons.compare;
import java.text.Collator;
import java.util.Comparator;
import java.util.Locale;
import javax.annotation.Nonnull;
import javax.annotation.Nullable;
import javax.annotation.concurrent.Immutable;
import com.helger.commons.annotation.PresentForCodeCoverage;
import com.helger.commons.equals.EqualsHelper;
import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
/**
* A small helper class that provides comparison methods that are
* null safe. Also provides secure ways to compare double and float
* values.
*
* @author Philip Helger
*/
@Immutable
public final class CompareHelper
{
/** By default null values come first */
public static final boolean DEFAULT_NULL_VALUES_COME_FIRST = true;
@PresentForCodeCoverage
private static final CompareHelper INSTANCE = new CompareHelper ();
private CompareHelper ()
{}
/**
* Special version for boolean, true before false
*
* @param b1
* First value
* @param b2
* Second value
* @return -1, 0 or + 1
*/
public static int compareTrueBeforeFalse (final boolean b1, final boolean b2)
{
if (b1 == b2)
return 0;
return b1 ? +1 : -1;
}
/**
* Special version for boolean, true before false
*
* @param b1
* First value
* @param b2
* Second value
* @return -1, 0 or + 1
*/
public static int compareFalseBeforeTrue (final boolean b1, final boolean b2)
{
if (b1 == b2)
return 0;
return b1 ? -1 : +1;
}
/**
* Special version for byte
*
* @param n1
* First value
* @param n2
* Second value
* @return value <0, 0 or >0.
*/
public static int compare (final byte n1, final byte n2)
{
return Byte.compare (n1, n2);
}
/**
* Special version for byte
*
* @param n1
* First value
* @param n2
* Second value
* @return value <0, 0 or >0.
*/
public static int compare (final char n1, final char n2)
{
return Character.compare (n1, n2);
}
/**
* Special version for doubles
*
* @param d1
* First value
* @param d2
* Second value
* @return value <0, 0 or >0.
*/
public static int compare (final double d1, final double d2)
{
return Double.compare (d1, d2);
}
/**
* Special version for floats
*
* @param f1
* First value
* @param f2
* Second value
* @return value <0, 0 or >0.
*/
public static int compare (final float f1, final float f2)
{
return Float.compare (f1, f2);
}
/**
* Special version for int
*
* @param n1
* First value
* @param n2
* Second value
* @return value <0, 0 or >0.
*/
public static int compare (final int n1, final int n2)
{
return Integer.compare (n1, n2);
}
/**
* Special version for long
*
* @param n1
* First value
* @param n2
* Second value
* @return value <0, 0 or >0.
*/
public static int compare (final long n1, final long n2)
{
return Long.compare (n1, n2);
}
/**
* Special version for short
*
* @param n1
* First value
* @param n2
* Second value
* @return value <0, 0 or >0.
*/
public static int compare (final short n1, final short n2)
{
return Short.compare (n1, n2);
}
/**
* Compare the passed items and handle null values correctly. A
* null value is always smaller than a non-null
* value.
*
* @param
* Any comparable object to be used. Both need to be of the same type.
* @param aObj1
* First object to compare. May be null.
* @param aObj2
* Second object to compare. May be null.
* @return 0 if they are equal (or both null), -1 or +1.
*/
public static > int compare (@Nullable final DATATYPE aObj1,
@Nullable final DATATYPE aObj2)
{
// Legacy behavior: null values come first
return compare (aObj1, aObj2, DEFAULT_NULL_VALUES_COME_FIRST);
}
/**
* Compare the passed items and handle null values correctly. A
* null value is always smaller than a non-null
* value.
*
* @param
* Any comparable object to be used. Both need to be of the same type.
* @param aObj1
* First object to compare. May be null.
* @param aObj2
* Second object to compare. May be null.
* @param bNullValuesComeFirst
* if true null values are ordered before
* non-null values
* @return 0 if they are equal (or both null), -1 or +1.
*/
public static > int compare (@Nullable final DATATYPE aObj1,
@Nullable final DATATYPE aObj2,
final boolean bNullValuesComeFirst)
{
if (EqualsHelper.identityEqual (aObj1, aObj2))
return 0;
if (aObj1 == null)
return bNullValuesComeFirst ? -1 : +1;
if (aObj2 == null)
return bNullValuesComeFirst ? +1 : -1;
return aObj1.compareTo (aObj2);
}
/**
* Compare the passed items and handle null values correctly. A
* null value is always smaller than a non-null
* value.
*
* @param
* Any object to be used. Both need to be of the same type.
* @param aObj1
* First object to compare. May be null.
* @param aObj2
* Second object to compare. May be null.
* @param aComp
* The comparator to be used if both parameters are not
* null. The comparator itself may not be
* null.
* @return 0 if they are equal (or both null), -1 or +1.
*/
public static int compare (@Nullable final DATATYPE aObj1,
@Nullable final DATATYPE aObj2,
@Nonnull final Comparator aComp)
{
// Legacy behavior: null values come first
return compare (aObj1, aObj2, aComp, DEFAULT_NULL_VALUES_COME_FIRST);
}
/**
* Compare the passed items and handle null values correctly. A
* null value is always smaller than a non-null
* value.
*
* @param
* Any object to be used. Both need to be of the same type.
* @param aObj1
* First object to compare. May be null.
* @param aObj2
* Second object to compare. May be null.
* @param aComp
* The comparator to be used if both parameters are not
* null. The comparator itself may not be
* null.
* @param bNullValuesComeFirst
* if true null values are ordered before
* non-null values
* @return 0 if they are equal (or both null), -1 or +1.
*/
public static int compare (@Nullable final DATATYPE aObj1,
@Nullable final DATATYPE aObj2,
@Nonnull final Comparator aComp,
final boolean bNullValuesComeFirst)
{
if (EqualsHelper.identityEqual (aObj1, aObj2))
return 0;
if (aObj1 == null)
return bNullValuesComeFirst ? -1 : +1;
if (aObj2 == null)
return bNullValuesComeFirst ? +1 : -1;
return aComp.compare (aObj1, aObj2);
}
public static int compare (@Nullable final String sStr1, @Nullable final String sStr2, @Nonnull final Locale aSortLocale)
{
// Legacy behavior: null values come first
return compare (sStr1, sStr2, aSortLocale, DEFAULT_NULL_VALUES_COME_FIRST);
}
public static int compare (@Nullable final String sStr1,
@Nullable final String sStr2,
@Nonnull final Locale aSortLocale,
final boolean bNullValuesComeFirst)
{
return compare (sStr1, sStr2, CollatorHelper.getCollatorSpaceBeforeDot (aSortLocale), bNullValuesComeFirst);
}
public static int compare (@Nullable final String sStr1, @Nullable final String sStr2, @Nonnull final Collator aCollator)
{
// Legacy behavior: null values come first
return compare (sStr1, sStr2, aCollator, DEFAULT_NULL_VALUES_COME_FIRST);
}
@SuppressFBWarnings ({ "ES_COMPARING_PARAMETER_STRING_WITH_EQ" })
public static int compare (@Nullable final String sStr1,
@Nullable final String sStr2,
@Nonnull final Collator aCollator,
final boolean bNullValuesComeFirst)
{
if (EqualsHelper.identityEqual (sStr1, sStr2))
return 0;
if (sStr1 == null)
return bNullValuesComeFirst ? -1 : +1;
if (sStr2 == null)
return bNullValuesComeFirst ? +1 : -1;
return aCollator.compare (sStr1, sStr2);
}
public static int compareIgnoreCase (@Nullable final String sStr1, @Nullable final String sStr2)
{
// Legacy behavior: null values come first
return compareIgnoreCase (sStr1, sStr2, DEFAULT_NULL_VALUES_COME_FIRST);
}
@SuppressFBWarnings ({ "ES_COMPARING_PARAMETER_STRING_WITH_EQ" })
public static int compareIgnoreCase (@Nullable final String sStr1, @Nullable final String sStr2, final boolean bNullValuesComeFirst)
{
if (EqualsHelper.identityEqual (sStr1, sStr2))
return 0;
if (sStr1 == null)
return bNullValuesComeFirst ? -1 : +1;
if (sStr2 == null)
return bNullValuesComeFirst ? +1 : -1;
return sStr1.compareToIgnoreCase (sStr2);
}
}