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refactored to Generics and added isArrayIndexValid

This commit is contained in:
MarkDacek 2018-07-08 16:15:54 -04:00
parent 9379d0d36a
commit 2521d9619f
2 changed files with 41 additions and 10 deletions
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36
src/main/java/org/apache/commons/lang3/ArrayUtils.java
View File

@ -8675,26 +8675,26 @@ public class ArrayUtils {
/** /**
* Gets an element from the array if the array is non-null and appropriately long, otherwise returns null * Gets an element from the array if the array is non-null and appropriately long, otherwise returns null
* * @param <T> the component type of the array
* @param array the array holding the desired object * @param array the array holding the desired element
* @param index the index of the object in the array * @param index the index of the element in the array
* @return The Object in the array at the index, or null if it is ill-formatted * @return The element in the array at the index, or null if it is ill-formatted
* @since 3.8 * @since 3.8
*/ */
public static Object get(Object[] array, int index){ public static <T> T get(T[] array, int index){
return get(array, index, null); return get(array, index, null);
} }
/** /**
* Gets an element from the array if the array is non-null and appropriately long, otherwise returns the specified value * Gets an element from the array if the array is non-null and appropriately long, otherwise returns the specified value
* * @param <T> the component type of the array
* @param array the array holding the desired object * @param array the array holding the desired element
* @param index the index of the object in the array * @param index the index of the element in the array
* @param defaultReturn the object to be returned if the array is null or shorter than the index * @param defaultReturn the object to be returned if the array is null or shorter than the index
* @return The object in the array at the specified index, or the given Object if it is ill-formatted * @return The element in the array at the specified index, or the given argument if it is ill-formatted
* @since 3.8 * @since 3.8
*/ */
public static Object get(Object[] array, int index, Object defaultReturn){ public static <T> T get(T[] array, int index, T defaultReturn){
if(getLength(array) == 0 || array.length <= index){ if(getLength(array) == 0 || array.length <= index){
return defaultReturn; return defaultReturn;
} }
@ -8705,4 +8705,20 @@ public class ArrayUtils {
return array[index]; return array[index];
} }
/**
* Gets an element from the array if the array is non-null and appropriately long, otherwise returns the specified value
* @param <T> the component type of the array
* @param array the array holding the desired element
* @param index the index of the element in the array
* @return Whether the given index is safely-accessible in the given array
* @since 3.8
*/
public static <T> boolean isArrayIndexValid(T[] array, int index){
if(getLength(array) == 0 || array.length <= index){
return false;
}
return index >= 0;
}
} }

15
src/test/java/org/apache/commons/lang3/ArrayUtilsTest.java
View File

@ -5127,4 +5127,19 @@ public class ArrayUtilsTest {
//negative index //negative index
assertEquals("Hello World", ArrayUtils.get(array, -1)); assertEquals("Hello World", ArrayUtils.get(array, -1));
} }
@Test
public void testIsArrayIndexValid(){
assertFalse(ArrayUtils.isArrayIndexValid(null, 0));
String[] array = new String[1];
//too big
assertFalse(ArrayUtils.isArrayIndexValid(array, 1));
//negative index
assertFalse(ArrayUtils.isArrayIndexValid(array, -1));
//good to go
assertTrue(ArrayUtils.isArrayIndexValid(array, 0));
}
} }