litesoft
@ 964
litesoft / trunk / GWT_Sandbox / FormEngine / src / com / temp / common / shared / utils / CollectionsUtils.java
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package com.temp.common.shared.utils; import java.util.*; /** * Utility methods around Collections / Arrays to reduce the code in other * places (e.g. the Activities). * * @author georgs */ public class CollectionsUtils { public static <T> List<T> deNull( List<T> list ) { if ( list != null ) { // can not "in line" as compiler gets confused! return list; } return Collections.emptyList(); } public static <T> List<T> noEmpty( List<T> list ) { return isEmpty( list ) ? null : list; } public static boolean isEmpty( Collection<?> collection ) { return (collection == null) || collection.isEmpty(); } public static boolean isEmpty( Map<?, ?> collection ) { return (collection == null) || collection.isEmpty(); } public static boolean isEmpty( Object[] array ) { return (array == null) || (array.length == 0); } /** * Use type inference to create a map - from Guava */ public static <V> List<V> newArrayList() { return new ArrayList<V>(); } /** * Use type inference to create a map - from Guava */ public static <K, V> Map<K, V> newHashMap() { return new HashMap<K, V>(); } public static Map<String, String> newMap( String... keyValuePairs ) { Map<String, String> map = newHashMap(); if ( !isEmpty( keyValuePairs ) ) { if ( (keyValuePairs.length & 1) == 1 ) { // Odd == Not Paired! throw new IllegalArgumentException( "To construct a String String Map, must provide Strings in pairs (key, value)" ); } for ( int i = 0; i < keyValuePairs.length; ) { String key = keyValuePairs[i++]; String value = keyValuePairs[i++]; addNonEmptiesTo( map, key, value ); } } return map; } public static Map<String, String> addNonEmptiesTo( Map<String, String> map, String key, String value ) { map.put( Assert.notNullOrEmpty( "key", key ), Assert.notNullOrEmpty( "value", value ) ); return map; } public static <K, V> Map<K, V> addNonNullsTo( Map<K, V> map, K key, V value ) { Assert.notNull( "key", key ); Assert.notNull( "value", value ); map.put( key, value ); return map; } } |
Commits for litesoft/trunk/GWT_Sandbox/FormEngine/src/com/temp/common/shared/utils/CollectionsUtils.java
Revision | Author | Commited | Message |
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964 | GeorgeS | Fri 01 Aug, 2014 03:18:23 +0000 | ! |