/**
*
* Copyright (c) 2006-2017, Speedment, Inc. All Rights Reserved.
*
* 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.speedment.common.invariant;
import java.util.Arrays;
import java.util.Collection;
import java.util.Map;
import java.util.NoSuchElementException;
import static java.util.Objects.requireNonNull;
/**
*
* @author pemi
*/
public final class NullUtil {
private static final String FIRST_ARG_IS_NULL = "First argument is null";
private static final String SECOND_ARG_IS_NULL = "Second argument is null";
private static final String THIRD_ARG_IS_NULL = "Third argument is null";
private static final String FOURTH_ARG_IS_NULL = "Fourth argument is null";
private static final String FIFTH_ARG_IS_NULL = "Fifth argument is null";
private static final String SIXTH_ARG_IS_NULL = "Sixth argument is null";
private static final String SEVENTH_ARG_IS_NULL = "Seventh argument is null";
private static final String EIGHT_ARG_IS_NULL = "Eight argument is null";
/**
* Checks if this array is non null and also that all members are non-null.
* If a null is detected a NullPointerException is thrown.
*
* @param <T> array type
* @param array to check
* @return the same array instance as provided
* @throws NullPointerException if a null is found in the array or if the
* array itself is null
*/
public static <T> T[] requireNonNullElements(T[] array) {
requireNonNull(array, "The provided array is null.");
int len = array.length;
for (int i = 0; i < len; i++) {
if (array[i] == null) {
throw new NullPointerException("Item " + i + " in the array " + Arrays.toString(array) + " is null");
}
}
return array;
}
/**
* Checks if this collection is non null and also that all members are
* non-null. If a null is detected a NullPointerException is thrown.
*
* @param <E> the inner type of the collection
* @param <T> collection type
* @param collection to check
* @return the same collection instance as provided
* @throws NullPointerException if a null is found in the collection or if
* the array itself is null
*/
public static <E, T extends Collection<E>> T requireNonNullElements(T collection) {
requireNonNull(collection, "The provided collection is null.");
int i = 0;
for (E item : collection) {
if (item == null) {
throw new NullPointerException("Element " + i + " in the collection " + collection + " is null");
}
i++;
}
return collection;
}
/**
* Checks if this array is non null and also that all members are non-null.
* If a null is detected a NullPointerException is thrown.
*
* @param <T> array type
* @param array to check
* @param msg to show if a null is detected
* @return the same array instance as provided
* @throws NullPointerException if a null is found in the array or if the
* array itself is null
*/
public static <T> T[] requireNonNullElements(T[] array, String msg) {
requireNonNull(array, msg);
int len = array.length;
for (int i = 0; i < len; i++) {
if (array[i] == null) {
throw new NullPointerException(msg + ", item " + i + " in the array " + Arrays.toString(array) + " is null");
}
}
return array;
}
/**
* Checks if this element is non null. If a null is detected a
* NullPointerException is thrown.
*
* @param o0 object to check
* @throws NullPointerException if the element is null
*/
public static void requireNonNulls(Object o0) {
if (o0 == null) {
throw new NullPointerException(FIRST_ARG_IS_NULL);
}
}
/**
* Checks if the provided elements all are non null. If a null is detected a
* NullPointerException is thrown.
*
* @param o0 object to check
* @param o1 object to check
* @throws NullPointerException if at least one of the elements are null
*/
public static void requireNonNulls(Object o0, Object o1) {
if (o0 == null) {
throw new NullPointerException(FIRST_ARG_IS_NULL);
}
if (o1 == null) {
throw new NullPointerException(SECOND_ARG_IS_NULL);
}
}
/**
* Checks if the provided elements all are non null. If a null is detected a
* NullPointerException is thrown.
*
* @param o0 object to check
* @param o1 object to check
* @param o2 object to check
* @throws NullPointerException if at least one of the elements are null
*/
public static void requireNonNulls(Object o0, Object o1, Object o2) {
if (o0 == null) {
throw new NullPointerException(FIRST_ARG_IS_NULL);
}
if (o1 == null) {
throw new NullPointerException(SECOND_ARG_IS_NULL);
}
if (o2 == null) {
throw new NullPointerException(THIRD_ARG_IS_NULL);
}
}
/**
* Checks if the provided elements all are non null. If a null is detected a
* NullPointerException is thrown.
*
* @param o0 object to check
* @param o1 object to check
* @param o2 object to check
* @param o3 object to check
* @throws NullPointerException if at least one of the elements are null
*/
public static void requireNonNulls(Object o0, Object o1, Object o2, Object o3) {
if (o0 == null) {
throw new NullPointerException(FIRST_ARG_IS_NULL);
}
if (o1 == null) {
throw new NullPointerException(SECOND_ARG_IS_NULL);
}
if (o2 == null) {
throw new NullPointerException(THIRD_ARG_IS_NULL);
}
if (o3 == null) {
throw new NullPointerException(FOURTH_ARG_IS_NULL);
}
}
/**
* Checks if the provided elements all are non null. If a null is detected a
* NullPointerException is thrown.
*
* @param o0 object to check
* @param o1 object to check
* @param o2 object to check
* @param o3 object to check
* @param o4 object to check
* @throws NullPointerException if at least one of the elements are null
*/
public static void requireNonNulls(Object o0, Object o1, Object o2, Object o3, Object o4) {
if (o0 == null) {
throw new NullPointerException(FIRST_ARG_IS_NULL);
}
if (o1 == null) {
throw new NullPointerException(SECOND_ARG_IS_NULL);
}
if (o2 == null) {
throw new NullPointerException(THIRD_ARG_IS_NULL);
}
if (o3 == null) {
throw new NullPointerException(FOURTH_ARG_IS_NULL);
}
if (o4 == null) {
throw new NullPointerException(FIFTH_ARG_IS_NULL);
}
}
/**
* Checks if the provided elements all are non null. If a null is detected a
* NullPointerException is thrown.
*s
* @param o0 object to check
* @param o1 object to check
* @param o2 object to check
* @param o3 object to check
* @param o4 object to check
* @param o5 object to check
* @throws NullPointerException if at least one of the elements are null
*/
public static void requireNonNulls(Object o0, Object o1, Object o2, Object o3, Object o4, Object o5) {
requireNonNulls(o0, o1, o2, o3, o4);
if (o5 == null) {
throw new NullPointerException(SIXTH_ARG_IS_NULL);
}
}
/**
* Checks if the provided elements all are non null. If a null is detected a
* NullPointerException is thrown.
*
* @param o0 object to check
* @param o1 object to check
* @param o2 object to check
* @param o3 object to check
* @param o4 object to check
* @param o5 object to check
* @param o6 object to check
* @throws NullPointerException if at least one of the elements are null
*/
public static void requireNonNulls(Object o0, Object o1, Object o2, Object o3, Object o4, Object o5, Object o6) {
requireNonNulls(o0, o1, o2, o3, o4);
if (o5 == null) {
throw new NullPointerException(SIXTH_ARG_IS_NULL);
}
if (o6 == null) {
throw new NullPointerException(SEVENTH_ARG_IS_NULL);
}
}
/**
* Checks if the provided elements all are non null. If a null is detected a
* NullPointerException is thrown.
*
* @param o0 object to check
* @param o1 object to check
* @param o2 object to check
* @param o3 object to check
* @param o4 object to check
* @param o5 object to check
* @param o6 object to check
* @param o7 object to check
* @throws NullPointerException if at least one of the elements are null
*/
public static void requireNonNulls(Object o0, Object o1, Object o2, Object o3, Object o4, Object o5, Object o6, Object o7) {
requireNonNulls(o0, o1, o2, o3, o4);
if (o5 == null) {
throw new NullPointerException(SIXTH_ARG_IS_NULL);
}
if (o6 == null) {
throw new NullPointerException(SEVENTH_ARG_IS_NULL);
}
if (o7 == null) {
throw new NullPointerException(EIGHT_ARG_IS_NULL);
}
}
/**
* Checks if the provided map contains all the provided required non-null
* key(s).
*
* @param <K> key type
* @param <V> value type
* @param map to check
* @param requiredKeys to check for existence
* @return the same instance of the provided map
* @throws NoSuchElementException if at least one required key is not a key
* in the provided Map
* @throws NullPointerException if the provided Map is null or if at least
* one of the required key are null
*/
@SafeVarargs // Iterating over an array is safe
@SuppressWarnings("varargs")
public static <K, V> Map<K, V> requireKeys(Map<K, V> map, K... requiredKeys) {
requireNonNull(map);
requireNonNullElements(requiredKeys);
for (final K key : requiredKeys) {
if (!map.containsKey(key)) {
throw new NoSuchElementException("The Map does not contain the key " + key);
}
}
return map;
}
/**
* Checks if the provided map contains all the provided required non-null
* key(s).
*
* @param <K> key type
* @param <V> value type
* @param map to check
* @param requiredKey to check for existence
* @return the same instance of the provided map
* @throws NoSuchElementException if the required key is not a key in the
* provided Map
* @throws NullPointerException if the provided Map is null or if the
* required key is null
*/
public static <K, V> Map<K, V> requireKeys(Map<K, V> map, K requiredKey) {
requireNonNull(map);
requireNonNull(requiredKey);
if (!map.containsKey(requiredKey)) {
throw new NoSuchElementException("The Map does not contain the key " + requiredKey);
}
return map;
}
/**
* Checks if the provided map contains all the provided required key(s).
*
* @param <K> key type
* @param <V> value type
* @param map to check
* @param requiredKeyA to check for existence
* @param requiredKeyB to check for existence
*
* @return the same instance of the provided map
* @throws NoSuchElementException if the required keys are not keys in the
* provided Map
* @throws NullPointerException if the provided Map is null
*/
public static <K, V> Map<K, V> requireKeys(Map<K, V> map, K requiredKeyA, K requiredKeyB) {
requireKeys(map, requiredKeyA);
requireKeys(map, requiredKeyB);
return map;
}
/**
* Checks if the provided map contains all the provided required key(s).
*
* @param <K> key type
* @param <V> value type
* @param map to check
* @param requiredKeyA to check for existence
* @param requiredKeyB to check for existence
* @param requiredKeyC to check for existence
* @return the same instance of the provided map
* @throws NoSuchElementException if the required keys are not keys in the
* provided Map
* @throws NullPointerException if the provided Map is null
*/
public static <K, V> Map<K, V> requireKeys(Map<K, V> map, K requiredKeyA, K requiredKeyB, K requiredKeyC) {
requireKeys(map, requiredKeyA);
requireKeys(map, requiredKeyB);
requireKeys(map, requiredKeyC);
return map;
}
private NullUtil() {
throw new UnsupportedOperationException();
}
}