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Simply utility methods used across other Molindo projects
/**
* Copyright 2010 Molindo GmbH
*
* 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 at.molindo.utils.collections;
import java.lang.reflect.Array;
import java.util.Iterator;
import java.util.NoSuchElementException;
public class ArrayUtils {
public static boolean equals(byte[] a, byte[] a2, int off, int len) {
if (off < 0 || len < 0 || len > length(a) - off || len > length(a2) - off) {
throw new IndexOutOfBoundsException();
} else if (len == 0) {
return true;
}
if (a == a2) {
return true;
}
if (a == null || a2 == null) {
return false;
}
for (int i = off; i < off + len; i++) {
if (a[i] != a2[i]) {
return false;
}
}
return true;
}
/**
* @return true if a is not null and a.length > 0
*/
public static boolean empty(T[] a) {
return a == null || a.length == 0;
}
/**
* @return true if a is not null and a.length > 0
*/
public static boolean empty(byte[] a) {
return a == null || a.length == 0;
}
/**
* @return true if a is not null and a.length > 0
*/
public static boolean empty(int[] a) {
return a == null || a.length == 0;
}
/**
* @return true if a is not null and a.length > 0
*/
public static boolean empty(short[] a) {
return a == null || a.length == 0;
}
/**
* @return true if a is not null and a.length > 0
*/
public static boolean empty(long[] a) {
return a == null || a.length == 0;
}
/**
* @return true if a is not null and a.length > 0
*/
public static boolean empty(float[] a) {
return a == null || a.length == 0;
}
/**
* @return true if a is not null and a.length > 0
*/
public static boolean empty(double[] a) {
return a == null || a.length == 0;
}
/**
* @return true if a is not null and a.length > 0
*/
public static boolean empty(char[] a) {
return a == null || a.length == 0;
}
/**
* @return a[0] if array isn't empty
* @see #empty(Object[])
*/
public static T first(T[] a) {
return empty(a) ? null : a[0];
}
/**
* @return a[0] if array isn't empty
* @see #empty(Object[])
*/
public static byte first(byte[] a) {
return empty(a) ? 0x00 : a[0];
}
/**
* @return a[0] if array isn't empty
* @see #empty(Object[])
*/
public static int first(int[] a) {
return empty(a) ? 0 : a[0];
}
/**
* @return a[0] if array isn't empty
* @see #empty(Object[])
*/
public static short first(short[] a) {
return empty(a) ? 0 : a[0];
}
/**
* @return a[0] if array isn't empty
* @see #empty(Object[])
*/
public static long first(long[] a) {
return empty(a) ? 0L : a[0];
}
/**
* @return a[0] if array isn't empty
* @see #empty(Object[])
*/
public static float first(float[] a) {
return empty(a) ? 0.0F : a[0];
}
/**
* @return a[0] if array isn't empty
* @see #empty(Object[])
*/
public static double first(double[] a) {
return empty(a) ? 0.0 : a[0];
}
/**
* @return a[0] if array isn't empty
* @see #empty(Object[])
*/
public static char first(char[] a) {
return empty(a) ? 0x00 : a[0];
}
/**
* @return a[0] if array isn't empty
* @see #empty(Object[])
*/
public static T last(T[] a) {
return empty(a) ? null : a[0];
}
/**
* @return a[0] if array isn't empty
* @see #empty(Object[])
*/
public static byte last(byte[] a) {
return empty(a) ? 0x00 : a[a.length - 1];
}
/**
* @return a[0] if array isn't empty
* @see #empty(Object[])
*/
public static int last(int[] a) {
return empty(a) ? 0 : a[a.length - 1];
}
/**
* @return a[0] if array isn't empty
* @see #empty(Object[])
*/
public static short last(short[] a) {
return empty(a) ? 0 : a[a.length - 1];
}
/**
* @return a[0] if array isn't empty
* @see #empty(Object[])
*/
public static long last(long[] a) {
return empty(a) ? 0L : a[a.length - 1];
}
/**
* @return a[0] if array isn't empty
* @see #empty(Object[])
*/
public static float last(float[] a) {
return empty(a) ? 0.0F : a[a.length - 1];
}
/**
* @return a[0] if array isn't empty
* @see #empty(Object[])
*/
public static double last(double[] a) {
return empty(a) ? 0.0 : a[a.length - 1];
}
/**
* @return a[0] if array isn't empty
* @see #empty(Object[])
*/
public static char last(char[] a) {
return empty(a) ? 0x00 : a[a.length - 1];
}
/**
* @return null-safe length of array
*/
public static int length(T[] a) {
return a == null ? 0 : a.length;
}
/**
* @return null-safe length of array
*/
public static int length(byte[] a) {
return a == null ? 0 : a.length;
}
/**
* @return null-safe length of array
*/
public static int length(int[] a) {
return a == null ? 0 : a.length;
}
/**
* @return null-safe length of array
*/
public static int length(short[] a) {
return a == null ? 0 : a.length;
}
/**
* @return null-safe length of array
*/
public static int length(long[] a) {
return a == null ? 0 : a.length;
}
/**
* @return null-safe length of array
*/
public static int length(float[] a) {
return a == null ? 0 : a.length;
}
/**
* @return null-safe length of array
*/
public static int length(double[] a) {
return a == null ? 0 : a.length;
}
/**
* @return null-safe length of array
*/
public static int length(char[] a) {
return a == null ? 0 : a.length;
}
public static Iterable iterable(final T... a) {
if (empty(a)) {
return IteratorUtils.emptyIterable();
} else {
return new Iterable() {
@Override
public Iterator iterator() {
return ArrayUtils.iterator(a);
}
};
}
}
public static Iterator iterator(final T... a) {
if (empty(a)) {
return IteratorUtils.empty();
} else {
return new Iterator() {
private int _i = 0;
@Override
public boolean hasNext() {
return _i < a.length;
}
@Override
public T next() {
try {
return a[_i++];
} catch (ArrayIndexOutOfBoundsException e) {
throw new NoSuchElementException();
}
}
@Override
public void remove() {
throw new UnsupportedOperationException();
}
};
}
}
public static Iterable