org.nerd4j.utils.lang.IsNot Maven / Gradle / Ivy
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* #%L
* Nerd4j Core
* %%
* Copyright (C) 2011 - 2019 Nerd4j
* %%
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Lesser Public License for more details.
*
* You should have received a copy of the GNU General Lesser Public
* License along with this program. If not, see
* .
* #L%
*/
package org.nerd4j.utils.lang;
import java.util.Collection;
import java.util.Map;
/**
* This class consists of {@code static} utility methods intended
* to operate {@code boolean} checks on objects.
*
*
* This class provides {@code null-safe} operations for the most
* common checks over {@link Object}s, {@link String}s, {@link Collection}s
* {@link Map}s, arrays and objects that implement the {@link Emptily} interface.
*
*
* The main aim of this class is to provide an easy and readable way
* to perform the most common checks in conditional statements and in
* functional statements like those provided by {@link java.util.stream.Stream}
* and {@link java.util.Optional}.
*
*
* - NULL
* - checks if an {@link Object} is NOT {@code null}
* - empty
* - checks if a {@link String}, a {@link Collection}, a {@link Map}, an array
* or an implementation of the {@link Emptily} interface is NOT empty
* - blank
* - checks if a {@link String} does NOT contain only characters
* satisfying {@link Character#isWhitespace(char)}
*
*
*
* This utility class can be used in {@code if} statements like:
*
* if( IsNot.empty(collection) )
* // Do something
*
* if( IsNot.blank(string) )
* // Do something
*
* or can be used as {@link java.util.function.Predicate}s in statements like:
*
* collection.stream().filter( IsNot::NULL ).// Do something
*
* or
*
* optional.filter( IsNot::blank ).// Do something
*
*
* @author Massimo Coluzzi
* @since 2.0.0
*/
public class IsNot
{
/**
* This class is intended to be static
* so there is no public constructor.
*/
IsNot() {}
/* ****************** */
/* CHECKS ON OBJECT */
/* ****************** */
/**
* Checks if the given value is not {@code null}.
*
* Since {@code null} is a keyword and therefore
* cannot be used as a method name, we choose
* to name the method in upper case.
*
* @param value the value to check.
* @return {@code false} if the value is {@code null}.
*/
public static boolean NULL( Object value )
{
return value != null;
}
/* ******************* */
/* CHECKS ON EMPTILY */
/* ******************* */
/**
* Checks if the given value is not {@code null} nor empty.
*
* @param value the value to check.
* @return {@code false} if the value is {@code null} or empty.
*/
public static boolean empty( Emptily value )
{
return value != null && ! value.isEmpty();
}
/* ****************** */
/* CHECKS ON STRING */
/* ****************** */
/**
* Checks if the given value is not {@code null} nor empty.
*
* @param value the value to check.
* @return {@code false} if the value is {@code null} or empty.
*/
public static boolean empty( String value )
{
return value != null && ! value.isEmpty();
}
/**
* Checks if the given value is not {@code null},
* nor empty and contains characters that do not satisfy
* the check performed by {@link Character#isWhitespace(char)}.
*
* @param value the value to check.
* @return {@code false} if the value is {@code null}, empty
* or contains only white spaces.
*/
public static boolean blank( String value )
{
return ! Is.blank( value );
}
/* ********************** */
/* CHECKS ON COLLECTION */
/* ********************** */
/**
* Checks if the given value is not {@code null} nor empty.
*
* @param value the value to check.
* @return {@code false} if the value is {@code null} or empty.
*/
public static boolean empty( Collection value )
{
return value != null && ! value.isEmpty();
}
/* *************** */
/* CHECKS ON MAP */
/* *************** */
/**
* Checks if the given value is not {@code null} nor empty.
*
* @param value the value to check.
* @return {@code false} if the value is {@code null} or empty.
*/
public static boolean empty( Map value )
{
return value != null && ! value.isEmpty();
}
/* ***************** */
/* CHECKS ON ARRAY */
/* ***************** */
/**
* Checks if the given value is not {@code null} nor empty.
*
* @param type of the elements in the array.
* @param value the value to check.
* @return {@code false} if the value is {@code null} or empty.
*/
public static boolean empty( V[] value )
{
return value != null && value.length > 0;
}
/**
* Checks if the given value is not {@code null} nor empty.
*
* @param value the value to check.
* @return {@code false} if the value is {@code null} or empty.
*/
public static boolean empty( boolean[] value )
{
return value != null && value.length > 0;
}
/**
* Checks if the given value is not {@code null} nor empty.
*
* @param value the value to check.
* @return {@code false} if the value is {@code null} or empty.
*/
public static boolean empty( char[] value )
{
return value != null && value.length > 0;
}
/**
* Checks if the given value is not {@code null} nor empty.
*
* @param value the value to check.
* @return {@code false} if the value is {@code null} or empty.
*/
public static boolean empty( byte[] value )
{
return value != null && value.length > 0;
}
/**
* Checks if the given value is not {@code null} nor empty.
*
* @param value the value to check.
* @return {@code false} if the value is {@code null} or empty.
*/
public static boolean empty( short[] value )
{
return value != null && value.length > 0;
}
/**
* Checks if the given value is not {@code null} nor empty.
*
* @param value the value to check.
* @return {@code false} if the value is {@code null} or empty.
*/
public static boolean empty( int[] value )
{
return value != null && value.length > 0;
}
/**
* Checks if the given value is not {@code null} nor empty.
*
* @param value the value to check.
* @return {@code false} if the value is {@code null} or empty.
*/
public static boolean empty( float[] value )
{
return value != null && value.length > 0;
}
/**
* Checks if the given value is not {@code null} nor empty.
*
* @param value the value to check.
* @return {@code false} if the value is {@code null} or empty.
*/
public static boolean empty( long[] value )
{
return value != null && value.length > 0;
}
/**
* Checks if the given value is not {@code null} nor empty.
*
* @param value the value to check.
* @return {@code false} if the value is {@code null} or empty.
*/
public static boolean empty( double[] value )
{
return value != null && value.length > 0;
}
}