| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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 org.apache.commons.lang3; |
| |
| import java.io.IOException; |
| import java.io.Serializable; |
| import java.lang.reflect.Array; |
| import java.lang.reflect.InvocationTargetException; |
| import java.lang.reflect.Method; |
| import java.time.Duration; |
| import java.util.Collection; |
| import java.util.Collections; |
| import java.util.Comparator; |
| import java.util.HashMap; |
| import java.util.Map; |
| import java.util.Objects; |
| import java.util.TreeSet; |
| import java.util.function.Supplier; |
| |
| import org.apache.commons.lang3.exception.CloneFailedException; |
| import org.apache.commons.lang3.mutable.MutableInt; |
| import org.apache.commons.lang3.text.StrBuilder; |
| import org.apache.commons.lang3.time.DurationUtils; |
| |
| /** |
| * <p>Operations on {@code Object}.</p> |
| * |
| * <p>This class tries to handle {@code null} input gracefully. |
| * An exception will generally not be thrown for a {@code null} input. |
| * Each method documents its behavior in more detail.</p> |
| * |
| * <p>#ThreadSafe#</p> |
| * @since 1.0 |
| */ |
| //@Immutable |
| @SuppressWarnings("deprecation") // deprecated class StrBuilder is imported |
| // because it is part of the signature of deprecated methods |
| public class ObjectUtils { |
| |
| // Null |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Class used as a null placeholder where {@code null} |
| * has another meaning.</p> |
| * |
| * <p>For example, in a {@code HashMap} the |
| * {@link java.util.HashMap#get(java.lang.Object)} method returns |
| * {@code null} if the {@code Map} contains {@code null} or if there is |
| * no matching key. The {@code Null} placeholder can be used to distinguish |
| * between these two cases.</p> |
| * |
| * <p>Another example is {@code Hashtable}, where {@code null} |
| * cannot be stored.</p> |
| */ |
| public static class Null implements Serializable { |
| /** |
| * Required for serialization support. Declare serialization compatibility with Commons Lang 1.0 |
| * |
| * @see java.io.Serializable |
| */ |
| private static final long serialVersionUID = 7092611880189329093L; |
| |
| /** |
| * Restricted constructor - singleton. |
| */ |
| Null() { |
| } |
| |
| /** |
| * <p>Ensure singleton.</p> |
| * |
| * @return the singleton value |
| */ |
| private Object readResolve() { |
| return NULL; |
| } |
| } |
| |
| private static final char AT_SIGN = '@'; |
| |
| /** |
| * <p>Singleton used as a {@code null} placeholder where |
| * {@code null} has another meaning.</p> |
| * |
| * <p>For example, in a {@code HashMap} the |
| * {@link java.util.HashMap#get(java.lang.Object)} method returns |
| * {@code null} if the {@code Map} contains {@code null} or if there |
| * is no matching key. The {@code Null} placeholder can be used to |
| * distinguish between these two cases.</p> |
| * |
| * <p>Another example is {@code Hashtable}, where {@code null} |
| * cannot be stored.</p> |
| * |
| * <p>This instance is Serializable.</p> |
| */ |
| public static final Null NULL = new Null(); |
| |
| /** |
| * Checks if all values in the array are not {@code nulls}. |
| * |
| * <p> |
| * If any value is {@code null} or the array is {@code null} then |
| * {@code false} is returned. If all elements in array are not |
| * {@code null} or the array is empty (contains no elements) {@code true} |
| * is returned. |
| * </p> |
| * |
| * <pre> |
| * ObjectUtils.allNotNull(*) = true |
| * ObjectUtils.allNotNull(*, *) = true |
| * ObjectUtils.allNotNull(null) = false |
| * ObjectUtils.allNotNull(null, null) = false |
| * ObjectUtils.allNotNull(null, *) = false |
| * ObjectUtils.allNotNull(*, null) = false |
| * ObjectUtils.allNotNull(*, *, null, *) = false |
| * </pre> |
| * |
| * @param values the values to test, may be {@code null} or empty |
| * @return {@code false} if there is at least one {@code null} value in the array or the array is {@code null}, |
| * {@code true} if all values in the array are not {@code null}s or array contains no elements. |
| * @since 3.5 |
| */ |
| public static boolean allNotNull(final Object... values) { |
| if (values == null) { |
| return false; |
| } |
| |
| for (final Object val : values) { |
| if (val == null) { |
| return false; |
| } |
| } |
| |
| return true; |
| } |
| |
| /** |
| * Checks if all values in the given array are {@code null}. |
| * |
| * <p> |
| * If all the values are {@code null} or the array is {@code null} |
| * or empty, then {@code true} is returned, otherwise {@code false} is returned. |
| * </p> |
| * |
| * <pre> |
| * ObjectUtils.allNull(*) = false |
| * ObjectUtils.allNull(*, null) = false |
| * ObjectUtils.allNull(null, *) = false |
| * ObjectUtils.allNull(null, null, *, *) = false |
| * ObjectUtils.allNull(null) = true |
| * ObjectUtils.allNull(null, null) = true |
| * </pre> |
| * |
| * @param values the values to test, may be {@code null} or empty |
| * @return {@code true} if all values in the array are {@code null}s, |
| * {@code false} if there is at least one non-null value in the array. |
| * @since 3.11 |
| */ |
| public static boolean allNull(final Object... values) { |
| return !anyNotNull(values); |
| } |
| |
| /** |
| * Checks if any value in the given array is not {@code null}. |
| * |
| * <p> |
| * If all the values are {@code null} or the array is {@code null} |
| * or empty then {@code false} is returned. Otherwise {@code true} is returned. |
| * </p> |
| * |
| * <pre> |
| * ObjectUtils.anyNotNull(*) = true |
| * ObjectUtils.anyNotNull(*, null) = true |
| * ObjectUtils.anyNotNull(null, *) = true |
| * ObjectUtils.anyNotNull(null, null, *, *) = true |
| * ObjectUtils.anyNotNull(null) = false |
| * ObjectUtils.anyNotNull(null, null) = false |
| * </pre> |
| * |
| * @param values the values to test, may be {@code null} or empty |
| * @return {@code true} if there is at least one non-null value in the array, |
| * {@code false} if all values in the array are {@code null}s. |
| * If the array is {@code null} or empty {@code false} is also returned. |
| * @since 3.5 |
| */ |
| public static boolean anyNotNull(final Object... values) { |
| return firstNonNull(values) != null; |
| } |
| |
| /** |
| * Checks if any value in the given array is {@code null}. |
| * |
| * <p> |
| * If any of the values are {@code null} or the array is {@code null}, |
| * then {@code true} is returned, otherwise {@code false} is returned. |
| * </p> |
| * |
| * <pre> |
| * ObjectUtils.anyNull(*) = false |
| * ObjectUtils.anyNull(*, *) = false |
| * ObjectUtils.anyNull(null) = true |
| * ObjectUtils.anyNull(null, null) = true |
| * ObjectUtils.anyNull(null, *) = true |
| * ObjectUtils.anyNull(*, null) = true |
| * ObjectUtils.anyNull(*, *, null, *) = true |
| * </pre> |
| * |
| * @param values the values to test, may be {@code null} or empty |
| * @return {@code true} if there is at least one {@code null} value in the array, |
| * {@code false} if all the values are non-null. |
| * If the array is {@code null} or empty, {@code true} is also returned. |
| * @since 3.11 |
| */ |
| public static boolean anyNull(final Object... values) { |
| return !allNotNull(values); |
| } |
| |
| // cloning |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Clone an object.</p> |
| * |
| * @param <T> the type of the object |
| * @param obj the object to clone, null returns null |
| * @return the clone if the object implements {@link Cloneable} otherwise {@code null} |
| * @throws CloneFailedException if the object is cloneable and the clone operation fails |
| * @since 3.0 |
| */ |
| public static <T> T clone(final T obj) { |
| if (obj instanceof Cloneable) { |
| final Object result; |
| if (obj.getClass().isArray()) { |
| final Class<?> componentType = obj.getClass().getComponentType(); |
| if (componentType.isPrimitive()) { |
| int length = Array.getLength(obj); |
| result = Array.newInstance(componentType, length); |
| while (length-- > 0) { |
| Array.set(result, length, Array.get(obj, length)); |
| } |
| } else { |
| result = ((Object[]) obj).clone(); |
| } |
| } else { |
| try { |
| final Method clone = obj.getClass().getMethod("clone"); |
| result = clone.invoke(obj); |
| } catch (final NoSuchMethodException e) { |
| throw new CloneFailedException("Cloneable type " |
| + obj.getClass().getName() |
| + " has no clone method", e); |
| } catch (final IllegalAccessException e) { |
| throw new CloneFailedException("Cannot clone Cloneable type " |
| + obj.getClass().getName(), e); |
| } catch (final InvocationTargetException e) { |
| throw new CloneFailedException("Exception cloning Cloneable type " |
| + obj.getClass().getName(), e.getCause()); |
| } |
| } |
| @SuppressWarnings("unchecked") // OK because input is of type T |
| final T checked = (T) result; |
| return checked; |
| } |
| |
| return null; |
| } |
| |
| /** |
| * <p>Clone an object if possible.</p> |
| * |
| * <p>This method is similar to {@link #clone(Object)}, but will return the provided |
| * instance as the return value instead of {@code null} if the instance |
| * is not cloneable. This is more convenient if the caller uses different |
| * implementations (e.g. of a service) and some of the implementations do not allow concurrent |
| * processing or have state. In such cases the implementation can simply provide a proper |
| * clone implementation and the caller's code does not have to change.</p> |
| * |
| * @param <T> the type of the object |
| * @param obj the object to clone, null returns null |
| * @return the clone if the object implements {@link Cloneable} otherwise the object itself |
| * @throws CloneFailedException if the object is cloneable and the clone operation fails |
| * @since 3.0 |
| */ |
| public static <T> T cloneIfPossible(final T obj) { |
| final T clone = clone(obj); |
| return clone == null ? obj : clone; |
| } |
| |
| /** |
| * <p>Null safe comparison of Comparables. |
| * {@code null} is assumed to be less than a non-{@code null} value.</p> |
| * |
| * @param <T> type of the values processed by this method |
| * @param c1 the first comparable, may be null |
| * @param c2 the second comparable, may be null |
| * @return a negative value if c1 < c2, zero if c1 = c2 |
| * and a positive value if c1 > c2 |
| */ |
| public static <T extends Comparable<? super T>> int compare(final T c1, final T c2) { |
| return compare(c1, c2, false); |
| } |
| |
| /** |
| * <p>Null safe comparison of Comparables.</p> |
| * |
| * @param <T> type of the values processed by this method |
| * @param c1 the first comparable, may be null |
| * @param c2 the second comparable, may be null |
| * @param nullGreater if true {@code null} is considered greater |
| * than a non-{@code null} value or if false {@code null} is |
| * considered less than a Non-{@code null} value |
| * @return a negative value if c1 < c2, zero if c1 = c2 |
| * and a positive value if c1 > c2 |
| * @see java.util.Comparator#compare(Object, Object) |
| */ |
| public static <T extends Comparable<? super T>> int compare(final T c1, final T c2, final boolean nullGreater) { |
| if (c1 == c2) { |
| return 0; |
| } else if (c1 == null) { |
| return nullGreater ? 1 : -1; |
| } else if (c2 == null) { |
| return nullGreater ? -1 : 1; |
| } |
| return c1.compareTo(c2); |
| } |
| |
| /** |
| * This method returns the provided value unchanged. |
| * This can prevent javac from inlining a constant |
| * field, e.g., |
| * |
| * <pre> |
| * public final static boolean MAGIC_FLAG = ObjectUtils.CONST(true); |
| * </pre> |
| * |
| * This way any jars that refer to this field do not |
| * have to recompile themselves if the field's value |
| * changes at some future date. |
| * |
| * @param v the boolean value to return |
| * @return the boolean v, unchanged |
| * @since 3.2 |
| */ |
| public static boolean CONST(final boolean v) { |
| return v; |
| } |
| |
| /** |
| * This method returns the provided value unchanged. |
| * This can prevent javac from inlining a constant |
| * field, e.g., |
| * |
| * <pre> |
| * public final static byte MAGIC_BYTE = ObjectUtils.CONST((byte) 127); |
| * </pre> |
| * |
| * This way any jars that refer to this field do not |
| * have to recompile themselves if the field's value |
| * changes at some future date. |
| * |
| * @param v the byte value to return |
| * @return the byte v, unchanged |
| * @since 3.2 |
| */ |
| public static byte CONST(final byte v) { |
| return v; |
| } |
| |
| /** |
| * This method returns the provided value unchanged. |
| * This can prevent javac from inlining a constant |
| * field, e.g., |
| * |
| * <pre> |
| * public final static char MAGIC_CHAR = ObjectUtils.CONST('a'); |
| * </pre> |
| * |
| * This way any jars that refer to this field do not |
| * have to recompile themselves if the field's value |
| * changes at some future date. |
| * |
| * @param v the char value to return |
| * @return the char v, unchanged |
| * @since 3.2 |
| */ |
| public static char CONST(final char v) { |
| return v; |
| } |
| |
| /** |
| * This method returns the provided value unchanged. |
| * This can prevent javac from inlining a constant |
| * field, e.g., |
| * |
| * <pre> |
| * public final static double MAGIC_DOUBLE = ObjectUtils.CONST(1.0); |
| * </pre> |
| * |
| * This way any jars that refer to this field do not |
| * have to recompile themselves if the field's value |
| * changes at some future date. |
| * |
| * @param v the double value to return |
| * @return the double v, unchanged |
| * @since 3.2 |
| */ |
| public static double CONST(final double v) { |
| return v; |
| } |
| |
| /** |
| * This method returns the provided value unchanged. |
| * This can prevent javac from inlining a constant |
| * field, e.g., |
| * |
| * <pre> |
| * public final static float MAGIC_FLOAT = ObjectUtils.CONST(1.0f); |
| * </pre> |
| * |
| * This way any jars that refer to this field do not |
| * have to recompile themselves if the field's value |
| * changes at some future date. |
| * |
| * @param v the float value to return |
| * @return the float v, unchanged |
| * @since 3.2 |
| */ |
| public static float CONST(final float v) { |
| return v; |
| } |
| |
| /** |
| * This method returns the provided value unchanged. |
| * This can prevent javac from inlining a constant |
| * field, e.g., |
| * |
| * <pre> |
| * public final static int MAGIC_INT = ObjectUtils.CONST(123); |
| * </pre> |
| * |
| * This way any jars that refer to this field do not |
| * have to recompile themselves if the field's value |
| * changes at some future date. |
| * |
| * @param v the int value to return |
| * @return the int v, unchanged |
| * @since 3.2 |
| */ |
| public static int CONST(final int v) { |
| return v; |
| } |
| |
| /** |
| * This method returns the provided value unchanged. |
| * This can prevent javac from inlining a constant |
| * field, e.g., |
| * |
| * <pre> |
| * public final static long MAGIC_LONG = ObjectUtils.CONST(123L); |
| * </pre> |
| * |
| * This way any jars that refer to this field do not |
| * have to recompile themselves if the field's value |
| * changes at some future date. |
| * |
| * @param v the long value to return |
| * @return the long v, unchanged |
| * @since 3.2 |
| */ |
| public static long CONST(final long v) { |
| return v; |
| } |
| |
| /** |
| * This method returns the provided value unchanged. |
| * This can prevent javac from inlining a constant |
| * field, e.g., |
| * |
| * <pre> |
| * public final static short MAGIC_SHORT = ObjectUtils.CONST((short) 123); |
| * </pre> |
| * |
| * This way any jars that refer to this field do not |
| * have to recompile themselves if the field's value |
| * changes at some future date. |
| * |
| * @param v the short value to return |
| * @return the short v, unchanged |
| * @since 3.2 |
| */ |
| public static short CONST(final short v) { |
| return v; |
| } |
| |
| /** |
| * This method returns the provided value unchanged. |
| * This can prevent javac from inlining a constant |
| * field, e.g., |
| * |
| * <pre> |
| * public final static String MAGIC_STRING = ObjectUtils.CONST("abc"); |
| * </pre> |
| * |
| * This way any jars that refer to this field do not |
| * have to recompile themselves if the field's value |
| * changes at some future date. |
| * |
| * @param <T> the Object type |
| * @param v the genericized Object value to return (typically a String). |
| * @return the genericized Object v, unchanged (typically a String). |
| * @since 3.2 |
| */ |
| public static <T> T CONST(final T v) { |
| return v; |
| } |
| |
| /** |
| * This method returns the provided value unchanged. |
| * This can prevent javac from inlining a constant |
| * field, e.g., |
| * |
| * <pre> |
| * public final static byte MAGIC_BYTE = ObjectUtils.CONST_BYTE(127); |
| * </pre> |
| * |
| * This way any jars that refer to this field do not |
| * have to recompile themselves if the field's value |
| * changes at some future date. |
| * |
| * @param v the byte literal (as an int) value to return |
| * @throws IllegalArgumentException if the value passed to v |
| * is larger than a byte, that is, smaller than -128 or |
| * larger than 127. |
| * @return the byte v, unchanged |
| * @since 3.2 |
| */ |
| public static byte CONST_BYTE(final int v) { |
| if (v < Byte.MIN_VALUE || v > Byte.MAX_VALUE) { |
| throw new IllegalArgumentException("Supplied value must be a valid byte literal between -128 and 127: [" + v + "]"); |
| } |
| return (byte) v; |
| } |
| |
| /** |
| * This method returns the provided value unchanged. |
| * This can prevent javac from inlining a constant |
| * field, e.g., |
| * |
| * <pre> |
| * public final static short MAGIC_SHORT = ObjectUtils.CONST_SHORT(127); |
| * </pre> |
| * |
| * This way any jars that refer to this field do not |
| * have to recompile themselves if the field's value |
| * changes at some future date. |
| * |
| * @param v the short literal (as an int) value to return |
| * @throws IllegalArgumentException if the value passed to v |
| * is larger than a short, that is, smaller than -32768 or |
| * larger than 32767. |
| * @return the byte v, unchanged |
| * @since 3.2 |
| */ |
| public static short CONST_SHORT(final int v) { |
| if (v < Short.MIN_VALUE || v > Short.MAX_VALUE) { |
| throw new IllegalArgumentException("Supplied value must be a valid byte literal between -32768 and 32767: [" + v + "]"); |
| } |
| return (short) v; |
| } |
| |
| /** |
| * <p>Returns a default value if the object passed is {@code null}.</p> |
| * |
| * <pre> |
| * ObjectUtils.defaultIfNull(null, null) = null |
| * ObjectUtils.defaultIfNull(null, "") = "" |
| * ObjectUtils.defaultIfNull(null, "zz") = "zz" |
| * ObjectUtils.defaultIfNull("abc", *) = "abc" |
| * ObjectUtils.defaultIfNull(Boolean.TRUE, *) = Boolean.TRUE |
| * </pre> |
| * |
| * @param <T> the type of the object |
| * @param object the {@code Object} to test, may be {@code null} |
| * @param defaultValue the default value to return, may be {@code null} |
| * @return {@code object} if it is not {@code null}, defaultValue otherwise |
| * TODO Rename to getIfNull in 4.0 |
| */ |
| public static <T> T defaultIfNull(final T object, final T defaultValue) { |
| return object != null ? object : defaultValue; |
| } |
| |
| // Null-safe equals/hashCode |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Compares two objects for equality, where either one or both |
| * objects may be {@code null}.</p> |
| * |
| * <pre> |
| * ObjectUtils.equals(null, null) = true |
| * ObjectUtils.equals(null, "") = false |
| * ObjectUtils.equals("", null) = false |
| * ObjectUtils.equals("", "") = true |
| * ObjectUtils.equals(Boolean.TRUE, null) = false |
| * ObjectUtils.equals(Boolean.TRUE, "true") = false |
| * ObjectUtils.equals(Boolean.TRUE, Boolean.TRUE) = true |
| * ObjectUtils.equals(Boolean.TRUE, Boolean.FALSE) = false |
| * </pre> |
| * |
| * @param object1 the first object, may be {@code null} |
| * @param object2 the second object, may be {@code null} |
| * @return {@code true} if the values of both objects are the same |
| * @deprecated this method has been replaced by {@code java.util.Objects.equals(Object, Object)} in Java 7 and will |
| * be removed from future releases. |
| */ |
| @Deprecated |
| public static boolean equals(final Object object1, final Object object2) { |
| if (object1 == object2) { |
| return true; |
| } |
| if (object1 == null || object2 == null) { |
| return false; |
| } |
| return object1.equals(object2); |
| } |
| |
| /** |
| * <p>Returns the first value in the array which is not {@code null}. |
| * If all the values are {@code null} or the array is {@code null} |
| * or empty then {@code null} is returned.</p> |
| * |
| * <pre> |
| * ObjectUtils.firstNonNull(null, null) = null |
| * ObjectUtils.firstNonNull(null, "") = "" |
| * ObjectUtils.firstNonNull(null, null, "") = "" |
| * ObjectUtils.firstNonNull(null, "zz") = "zz" |
| * ObjectUtils.firstNonNull("abc", *) = "abc" |
| * ObjectUtils.firstNonNull(null, "xyz", *) = "xyz" |
| * ObjectUtils.firstNonNull(Boolean.TRUE, *) = Boolean.TRUE |
| * ObjectUtils.firstNonNull() = null |
| * </pre> |
| * |
| * @param <T> the component type of the array |
| * @param values the values to test, may be {@code null} or empty |
| * @return the first value from {@code values} which is not {@code null}, |
| * or {@code null} if there are no non-null values |
| * @since 3.0 |
| */ |
| @SafeVarargs |
| public static <T> T firstNonNull(final T... values) { |
| if (values != null) { |
| for (final T val : values) { |
| if (val != null) { |
| return val; |
| } |
| } |
| } |
| return null; |
| } |
| |
| /** |
| * <p>Executes the given suppliers in order and returns the first return |
| * value where a value other than {@code null} is returned. |
| * Once a non-{@code null} value is obtained, all following suppliers are |
| * not executed anymore. |
| * If all the return values are {@code null} or no suppliers are provided |
| * then {@code null} is returned.</p> |
| * |
| * <pre> |
| * ObjectUtils.firstNonNullLazy(null, () -> null) = null |
| * ObjectUtils.firstNonNullLazy(() -> null, () -> "") = "" |
| * ObjectUtils.firstNonNullLazy(() -> "", () -> throw new IllegalStateException()) = "" |
| * ObjectUtils.firstNonNullLazy(() -> null, () -> "zz) = "zz" |
| * ObjectUtils.firstNonNullLazy() = null |
| * </pre> |
| * |
| * @param <T> the type of the return values |
| * @param suppliers the suppliers returning the values to test. |
| * {@code null} values are ignored. |
| * Suppliers may return {@code null} or a value of type @{code T} |
| * @return the first return value from {@code suppliers} which is not {@code null}, |
| * or {@code null} if there are no non-null values |
| * @since 3.10 |
| */ |
| @SafeVarargs |
| public static <T> T getFirstNonNull(final Supplier<T>... suppliers) { |
| if (suppliers != null) { |
| for (final Supplier<T> supplier : suppliers) { |
| if (supplier != null) { |
| final T value = supplier.get(); |
| if (value != null) { |
| return value; |
| } |
| } |
| } |
| } |
| return null; |
| } |
| |
| /** |
| * <p> |
| * Returns the given {@code object} is it is non-null, otherwise returns the Supplier's {@link Supplier#get()} |
| * value. |
| * </p> |
| * |
| * <p> |
| * The caller responsible for thread-safety and exception handling of default value supplier. |
| * </p> |
| * |
| * <pre> |
| * ObjectUtils.getIfNull(null, () -> null) = null |
| * ObjectUtils.getIfNull(null, null) = null |
| * ObjectUtils.getIfNull(null, () -> "") = "" |
| * ObjectUtils.getIfNull(null, () -> "zz") = "zz" |
| * ObjectUtils.getIfNull("abc", *) = "abc" |
| * ObjectUtils.getIfNull(Boolean.TRUE, *) = Boolean.TRUE |
| * </pre> |
| * |
| * @param <T> the type of the object |
| * @param object the {@code Object} to test, may be {@code null} |
| * @param defaultSupplier the default value to return, may be {@code null} |
| * @return {@code object} if it is not {@code null}, {@code defaultValueSupplier.get()} otherwise |
| * @since 3.10 |
| */ |
| public static <T> T getIfNull(final T object, final Supplier<T> defaultSupplier) { |
| return object != null ? object : defaultSupplier == null ? null : defaultSupplier.get(); |
| } |
| |
| /** |
| * <p>Gets the hash code of an object returning zero when the |
| * object is {@code null}.</p> |
| * |
| * <pre> |
| * ObjectUtils.hashCode(null) = 0 |
| * ObjectUtils.hashCode(obj) = obj.hashCode() |
| * </pre> |
| * |
| * @param obj the object to obtain the hash code of, may be {@code null} |
| * @return the hash code of the object, or zero if null |
| * @since 2.1 |
| * @deprecated this method has been replaced by {@code java.util.Objects.hashCode(Object)} in Java 7 and will be |
| * removed in future releases |
| */ |
| @Deprecated |
| public static int hashCode(final Object obj) { |
| // hashCode(Object) retained for performance, as hash code is often critical |
| return obj == null ? 0 : obj.hashCode(); |
| } |
| |
| /** |
| * <p>Gets the hash code for multiple objects.</p> |
| * |
| * <p>This allows a hash code to be rapidly calculated for a number of objects. |
| * The hash code for a single object is the <em>not</em> same as {@link #hashCode(Object)}. |
| * The hash code for multiple objects is the same as that calculated by an |
| * {@code ArrayList} containing the specified objects.</p> |
| * |
| * <pre> |
| * ObjectUtils.hashCodeMulti() = 1 |
| * ObjectUtils.hashCodeMulti((Object[]) null) = 1 |
| * ObjectUtils.hashCodeMulti(a) = 31 + a.hashCode() |
| * ObjectUtils.hashCodeMulti(a,b) = (31 + a.hashCode()) * 31 + b.hashCode() |
| * ObjectUtils.hashCodeMulti(a,b,c) = ((31 + a.hashCode()) * 31 + b.hashCode()) * 31 + c.hashCode() |
| * </pre> |
| * |
| * @param objects the objects to obtain the hash code of, may be {@code null} |
| * @return the hash code of the objects, or zero if null |
| * @since 3.0 |
| * @deprecated this method has been replaced by {@code java.util.Objects.hash(Object...)} in Java 7 and will be |
| * removed in future releases. |
| */ |
| @Deprecated |
| public static int hashCodeMulti(final Object... objects) { |
| int hash = 1; |
| if (objects != null) { |
| for (final Object object : objects) { |
| final int tmpHash = hashCode(object); |
| hash = hash * 31 + tmpHash; |
| } |
| } |
| return hash; |
| } |
| |
| /** |
| * <p>Appends the toString that would be produced by {@code Object} |
| * if a class did not override toString itself. {@code null} |
| * will throw a NullPointerException for either of the two parameters. </p> |
| * |
| * <pre> |
| * ObjectUtils.identityToString(appendable, "") = appendable.append("java.lang.String@1e23" |
| * ObjectUtils.identityToString(appendable, Boolean.TRUE) = appendable.append("java.lang.Boolean@7fa" |
| * ObjectUtils.identityToString(appendable, Boolean.TRUE) = appendable.append("java.lang.Boolean@7fa") |
| * </pre> |
| * |
| * @param appendable the appendable to append to |
| * @param object the object to create a toString for |
| * @throws IOException if an I/O error occurs. |
| * @since 3.2 |
| */ |
| public static void identityToString(final Appendable appendable, final Object object) throws IOException { |
| Validate.notNull(object, "object"); |
| appendable.append(object.getClass().getName()) |
| .append(AT_SIGN) |
| .append(Integer.toHexString(System.identityHashCode(object))); |
| } |
| |
| // Identity ToString |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Gets the toString that would be produced by {@code Object} |
| * if a class did not override toString itself. {@code null} |
| * will return {@code null}.</p> |
| * |
| * <pre> |
| * ObjectUtils.identityToString(null) = null |
| * ObjectUtils.identityToString("") = "java.lang.String@1e23" |
| * ObjectUtils.identityToString(Boolean.TRUE) = "java.lang.Boolean@7fa" |
| * </pre> |
| * |
| * @param object the object to create a toString for, may be |
| * {@code null} |
| * @return the default toString text, or {@code null} if |
| * {@code null} passed in |
| */ |
| public static String identityToString(final Object object) { |
| if (object == null) { |
| return null; |
| } |
| final String name = object.getClass().getName(); |
| final String hexString = Integer.toHexString(System.identityHashCode(object)); |
| final StringBuilder builder = new StringBuilder(name.length() + 1 + hexString.length()); |
| // @formatter:off |
| builder.append(name) |
| .append(AT_SIGN) |
| .append(hexString); |
| // @formatter:on |
| return builder.toString(); |
| } |
| |
| /** |
| * <p>Appends the toString that would be produced by {@code Object} |
| * if a class did not override toString itself. {@code null} |
| * will throw a NullPointerException for either of the two parameters. </p> |
| * |
| * <pre> |
| * ObjectUtils.identityToString(builder, "") = builder.append("java.lang.String@1e23" |
| * ObjectUtils.identityToString(builder, Boolean.TRUE) = builder.append("java.lang.Boolean@7fa" |
| * ObjectUtils.identityToString(builder, Boolean.TRUE) = builder.append("java.lang.Boolean@7fa") |
| * </pre> |
| * |
| * @param builder the builder to append to |
| * @param object the object to create a toString for |
| * @since 3.2 |
| * @deprecated as of 3.6, because StrBuilder was moved to commons-text, |
| * use one of the other {@code identityToString} methods instead |
| */ |
| @Deprecated |
| public static void identityToString(final StrBuilder builder, final Object object) { |
| Validate.notNull(object, "object"); |
| final String name = object.getClass().getName(); |
| final String hexString = Integer.toHexString(System.identityHashCode(object)); |
| builder.ensureCapacity(builder.length() + name.length() + 1 + hexString.length()); |
| builder.append(name) |
| .append(AT_SIGN) |
| .append(hexString); |
| } |
| |
| /** |
| * <p>Appends the toString that would be produced by {@code Object} |
| * if a class did not override toString itself. {@code null} |
| * will throw a NullPointerException for either of the two parameters. </p> |
| * |
| * <pre> |
| * ObjectUtils.identityToString(buf, "") = buf.append("java.lang.String@1e23" |
| * ObjectUtils.identityToString(buf, Boolean.TRUE) = buf.append("java.lang.Boolean@7fa" |
| * ObjectUtils.identityToString(buf, Boolean.TRUE) = buf.append("java.lang.Boolean@7fa") |
| * </pre> |
| * |
| * @param buffer the buffer to append to |
| * @param object the object to create a toString for |
| * @since 2.4 |
| */ |
| public static void identityToString(final StringBuffer buffer, final Object object) { |
| Validate.notNull(object, "object"); |
| final String name = object.getClass().getName(); |
| final String hexString = Integer.toHexString(System.identityHashCode(object)); |
| buffer.ensureCapacity(buffer.length() + name.length() + 1 + hexString.length()); |
| buffer.append(name) |
| .append(AT_SIGN) |
| .append(hexString); |
| } |
| |
| /** |
| * <p>Appends the toString that would be produced by {@code Object} |
| * if a class did not override toString itself. {@code null} |
| * will throw a NullPointerException for either of the two parameters. </p> |
| * |
| * <pre> |
| * ObjectUtils.identityToString(builder, "") = builder.append("java.lang.String@1e23" |
| * ObjectUtils.identityToString(builder, Boolean.TRUE) = builder.append("java.lang.Boolean@7fa" |
| * ObjectUtils.identityToString(builder, Boolean.TRUE) = builder.append("java.lang.Boolean@7fa") |
| * </pre> |
| * |
| * @param builder the builder to append to |
| * @param object the object to create a toString for |
| * @since 3.2 |
| */ |
| public static void identityToString(final StringBuilder builder, final Object object) { |
| Validate.notNull(object, "object"); |
| final String name = object.getClass().getName(); |
| final String hexString = Integer.toHexString(System.identityHashCode(object)); |
| builder.ensureCapacity(builder.length() + name.length() + 1 + hexString.length()); |
| builder.append(name) |
| .append(AT_SIGN) |
| .append(hexString); |
| } |
| |
| |
| // Constants (LANG-816): |
| /* |
| These methods ensure constants are not inlined by javac. |
| For example, typically a developer might declare a constant like so: |
| |
| public final static int MAGIC_NUMBER = 5; |
| |
| Should a different jar file refer to this, and the MAGIC_NUMBER |
| is changed a later date (e.g., MAGIC_NUMBER = 6), the different jar |
| file will need to recompile itself. This is because javac |
| typically inlines the primitive or String constant directly into |
| the bytecode, and removes the reference to the MAGIC_NUMBER field. |
| |
| To help the other jar (so that it does not need to recompile |
| when constants are changed) the original developer can declare |
| their constant using one of the CONST() utility methods, instead: |
| |
| public final static int MAGIC_NUMBER = CONST(5); |
| */ |
| |
| |
| // Empty checks |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Checks if an Object is empty or null.</p> |
| * |
| * The following types are supported: |
| * <ul> |
| * <li>{@link CharSequence}: Considered empty if its length is zero.</li> |
| * <li>{@code Array}: Considered empty if its length is zero.</li> |
| * <li>{@link Collection}: Considered empty if it has zero elements.</li> |
| * <li>{@link Map}: Considered empty if it has zero key-value mappings.</li> |
| * </ul> |
| * |
| * <pre> |
| * ObjectUtils.isEmpty(null) = true |
| * ObjectUtils.isEmpty("") = true |
| * ObjectUtils.isEmpty("ab") = false |
| * ObjectUtils.isEmpty(new int[]{}) = true |
| * ObjectUtils.isEmpty(new int[]{1,2,3}) = false |
| * ObjectUtils.isEmpty(1234) = false |
| * </pre> |
| * |
| * @param object the {@code Object} to test, may be {@code null} |
| * @return {@code true} if the object has a supported type and is empty or null, |
| * {@code false} otherwise |
| * @since 3.9 |
| */ |
| public static boolean isEmpty(final Object object) { |
| if (object == null) { |
| return true; |
| } |
| if (object instanceof CharSequence) { |
| return ((CharSequence) object).length() == 0; |
| } |
| if (object.getClass().isArray()) { |
| return Array.getLength(object) == 0; |
| } |
| if (object instanceof Collection<?>) { |
| return ((Collection<?>) object).isEmpty(); |
| } |
| if (object instanceof Map<?, ?>) { |
| return ((Map<?, ?>) object).isEmpty(); |
| } |
| return false; |
| } |
| |
| /** |
| * <p>Checks if an Object is not empty and not null.</p> |
| * |
| * The following types are supported: |
| * <ul> |
| * <li>{@link CharSequence}: Considered empty if its length is zero.</li> |
| * <li>{@code Array}: Considered empty if its length is zero.</li> |
| * <li>{@link Collection}: Considered empty if it has zero elements.</li> |
| * <li>{@link Map}: Considered empty if it has zero key-value mappings.</li> |
| * </ul> |
| * |
| * <pre> |
| * ObjectUtils.isNotEmpty(null) = false |
| * ObjectUtils.isNotEmpty("") = false |
| * ObjectUtils.isNotEmpty("ab") = true |
| * ObjectUtils.isNotEmpty(new int[]{}) = false |
| * ObjectUtils.isNotEmpty(new int[]{1,2,3}) = true |
| * ObjectUtils.isNotEmpty(1234) = true |
| * </pre> |
| * |
| * @param object the {@code Object} to test, may be {@code null} |
| * @return {@code true} if the object has an unsupported type or is not empty |
| * and not null, {@code false} otherwise |
| * @since 3.9 |
| */ |
| public static boolean isNotEmpty(final Object object) { |
| return !isEmpty(object); |
| } |
| |
| /** |
| * <p>Null safe comparison of Comparables.</p> |
| * |
| * @param <T> type of the values processed by this method |
| * @param values the set of comparable values, may be null |
| * @return |
| * <ul> |
| * <li>If any objects are non-null and unequal, the greater object. |
| * <li>If all objects are non-null and equal, the first. |
| * <li>If any of the comparables are null, the greater of the non-null objects. |
| * <li>If all the comparables are null, null is returned. |
| * </ul> |
| */ |
| @SafeVarargs |
| public static <T extends Comparable<? super T>> T max(final T... values) { |
| T result = null; |
| if (values != null) { |
| for (final T value : values) { |
| if (compare(value, result, false) > 0) { |
| result = value; |
| } |
| } |
| } |
| return result; |
| } |
| |
| /** |
| * Find the "best guess" middle value among comparables. If there is an even |
| * number of total values, the lower of the two middle values will be returned. |
| * @param <T> type of values processed by this method |
| * @param comparator to use for comparisons |
| * @param items to compare |
| * @return T at middle position |
| * @throws NullPointerException if items or comparator is {@code null} |
| * @throws IllegalArgumentException if items is empty or contains {@code null} values |
| * @since 3.0.1 |
| */ |
| @SafeVarargs |
| public static <T> T median(final Comparator<T> comparator, final T... items) { |
| Validate.notEmpty(items, "null/empty items"); |
| Validate.noNullElements(items); |
| Validate.notNull(comparator, "comparator"); |
| final TreeSet<T> sort = new TreeSet<>(comparator); |
| Collections.addAll(sort, items); |
| @SuppressWarnings("unchecked") //we know all items added were T instances |
| final |
| T result = (T) sort.toArray()[(sort.size() - 1) / 2]; |
| return result; |
| } |
| |
| /** |
| * Find the "best guess" middle value among comparables. If there is an even |
| * number of total values, the lower of the two middle values will be returned. |
| * @param <T> type of values processed by this method |
| * @param items to compare |
| * @return T at middle position |
| * @throws NullPointerException if items is {@code null} |
| * @throws IllegalArgumentException if items is empty or contains {@code null} values |
| * @since 3.0.1 |
| */ |
| @SafeVarargs |
| public static <T extends Comparable<? super T>> T median(final T... items) { |
| Validate.notEmpty(items); |
| Validate.noNullElements(items); |
| final TreeSet<T> sort = new TreeSet<>(); |
| Collections.addAll(sort, items); |
| @SuppressWarnings("unchecked") //we know all items added were T instances |
| final T result = (T) sort.toArray()[(sort.size() - 1) / 2]; |
| return result; |
| } |
| |
| // Comparable |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Null safe comparison of Comparables.</p> |
| * |
| * @param <T> type of the values processed by this method |
| * @param values the set of comparable values, may be null |
| * @return |
| * <ul> |
| * <li>If any objects are non-null and unequal, the lesser object. |
| * <li>If all objects are non-null and equal, the first. |
| * <li>If any of the comparables are null, the lesser of the non-null objects. |
| * <li>If all the comparables are null, null is returned. |
| * </ul> |
| */ |
| @SafeVarargs |
| public static <T extends Comparable<? super T>> T min(final T... values) { |
| T result = null; |
| if (values != null) { |
| for (final T value : values) { |
| if (compare(value, result, true) < 0) { |
| result = value; |
| } |
| } |
| } |
| return result; |
| } |
| |
| |
| // Mode |
| //----------------------------------------------------------------------- |
| /** |
| * Find the most frequently occurring item. |
| * |
| * @param <T> type of values processed by this method |
| * @param items to check |
| * @return most populous T, {@code null} if non-unique or no items supplied |
| * @since 3.0.1 |
| */ |
| @SafeVarargs |
| public static <T> T mode(final T... items) { |
| if (ArrayUtils.isNotEmpty(items)) { |
| final HashMap<T, MutableInt> occurrences = new HashMap<>(items.length); |
| for (final T t : items) { |
| final MutableInt count = occurrences.get(t); |
| if (count == null) { |
| occurrences.put(t, new MutableInt(1)); |
| } else { |
| count.increment(); |
| } |
| } |
| T result = null; |
| int max = 0; |
| for (final Map.Entry<T, MutableInt> e : occurrences.entrySet()) { |
| final int cmp = e.getValue().intValue(); |
| if (cmp == max) { |
| result = null; |
| } else if (cmp > max) { |
| max = cmp; |
| result = e.getKey(); |
| } |
| } |
| return result; |
| } |
| return null; |
| } |
| |
| /** |
| * <p>Compares two objects for inequality, where either one or both |
| * objects may be {@code null}.</p> |
| * |
| * <pre> |
| * ObjectUtils.notEqual(null, null) = false |
| * ObjectUtils.notEqual(null, "") = true |
| * ObjectUtils.notEqual("", null) = true |
| * ObjectUtils.notEqual("", "") = false |
| * ObjectUtils.notEqual(Boolean.TRUE, null) = true |
| * ObjectUtils.notEqual(Boolean.TRUE, "true") = true |
| * ObjectUtils.notEqual(Boolean.TRUE, Boolean.TRUE) = false |
| * ObjectUtils.notEqual(Boolean.TRUE, Boolean.FALSE) = true |
| * </pre> |
| * |
| * @param object1 the first object, may be {@code null} |
| * @param object2 the second object, may be {@code null} |
| * @return {@code false} if the values of both objects are the same |
| */ |
| public static boolean notEqual(final Object object1, final Object object2) { |
| return !equals(object1, object2); |
| } |
| |
| /** |
| * Checks that the specified object reference is not {@code null} or empty per {@link #isEmpty(Object)}. Use this |
| * method for validation, for example: |
| * |
| * <blockquote> |
| * |
| * <pre> |
| * public Foo(Bar bar) { |
| * this.bar = Objects.requireNonEmpty(bar); |
| * } |
| * </pre> |
| * |
| * </blockquote> |
| * |
| * @param <T> the type of the reference. |
| * @param obj the object reference to check for nullity. |
| * @return {@code obj} if not {@code null}. |
| * @throws NullPointerException if {@code obj} is {@code null}. |
| * @throws IllegalArgumentException if {@code obj} is empty per {@link #isEmpty(Object)}. |
| * @see #isEmpty(Object) |
| * @since 3.12.0 |
| */ |
| public static <T> T requireNonEmpty(final T obj) { |
| return requireNonEmpty(obj, "object"); |
| } |
| |
| /** |
| * Checks that the specified object reference is not {@code null} or empty per {@link #isEmpty(Object)}. Use this |
| * method for validation, for example: |
| * |
| * <blockquote> |
| * |
| * <pre> |
| * public Foo(Bar bar) { |
| * this.bar = Objects.requireNonEmpty(bar, "bar"); |
| * } |
| * </pre> |
| * |
| * </blockquote> |
| * |
| * @param <T> the type of the reference. |
| * @param obj the object reference to check for nullity. |
| * @param message the exception message. |
| * @return {@code obj} if not {@code null}. |
| * @throws NullPointerException if {@code obj} is {@code null}. |
| * @throws IllegalArgumentException if {@code obj} is empty per {@link #isEmpty(Object)}. |
| * @see #isEmpty(Object) |
| * @since 3.12.0 |
| */ |
| public static <T> T requireNonEmpty(final T obj, final String message) { |
| // check for null first to give the most precise exception. |
| Objects.requireNonNull(obj, message); |
| if (isEmpty(obj)) { |
| throw new IllegalArgumentException(message); |
| } |
| return obj; |
| } |
| |
| // ToString |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Gets the {@code toString} of an {@code Object} returning |
| * an empty string ("") if {@code null} input.</p> |
| * |
| * <pre> |
| * ObjectUtils.toString(null) = "" |
| * ObjectUtils.toString("") = "" |
| * ObjectUtils.toString("bat") = "bat" |
| * ObjectUtils.toString(Boolean.TRUE) = "true" |
| * </pre> |
| * |
| * @see StringUtils#defaultString(String) |
| * @see String#valueOf(Object) |
| * @param obj the Object to {@code toString}, may be null |
| * @return the passed in Object's toString, or {@code ""} if {@code null} input |
| * @since 2.0 |
| * @deprecated this method has been replaced by {@code java.util.Objects.toString(Object)} in Java 7 and will be |
| * removed in future releases. Note however that said method will return "null" for null references, while this |
| * method returns an empty String. To preserve behavior use {@code java.util.Objects.toString(myObject, "")} |
| */ |
| @Deprecated |
| public static String toString(final Object obj) { |
| return obj == null ? StringUtils.EMPTY : obj.toString(); |
| } |
| /** |
| * <p>Gets the {@code toString} of an {@code Object} returning |
| * a specified text if {@code null} input.</p> |
| * |
| * <pre> |
| * ObjectUtils.toString(null, null) = null |
| * ObjectUtils.toString(null, "null") = "null" |
| * ObjectUtils.toString("", "null") = "" |
| * ObjectUtils.toString("bat", "null") = "bat" |
| * ObjectUtils.toString(Boolean.TRUE, "null") = "true" |
| * </pre> |
| * |
| * @see StringUtils#defaultString(String,String) |
| * @see String#valueOf(Object) |
| * @param obj the Object to {@code toString}, may be null |
| * @param nullStr the String to return if {@code null} input, may be null |
| * @return the passed in Object's toString, or {@code nullStr} if {@code null} input |
| * @since 2.0 |
| * @deprecated this method has been replaced by {@code java.util.Objects.toString(Object, String)} in Java 7 and |
| * will be removed in future releases. |
| */ |
| @Deprecated |
| public static String toString(final Object obj, final String nullStr) { |
| return obj == null ? nullStr : obj.toString(); |
| } |
| |
| /** |
| * <p>Gets the {@code toString} of an {@code Object} returning |
| * a specified text if {@code null} input.</p> |
| * |
| * <pre> |
| * ObjectUtils.toString(obj, () -> expensive()) |
| * </pre> |
| * <pre> |
| * ObjectUtils.toString(null, () -> expensive()) = result of expensive() |
| * ObjectUtils.toString(null, () -> expensive()) = result of expensive() |
| * ObjectUtils.toString("", () -> expensive()) = "" |
| * ObjectUtils.toString("bat", () -> expensive()) = "bat" |
| * ObjectUtils.toString(Boolean.TRUE, () -> expensive()) = "true" |
| * </pre> |
| * |
| * @param obj the Object to {@code toString}, may be null |
| * @param supplier the Supplier of String used on {@code null} input, may be null |
| * @return the passed in Object's toString, or {@code nullStr} if {@code null} input |
| * @since 3.11 |
| */ |
| public static String toString(final Object obj, final Supplier<String> supplier) { |
| return obj == null ? supplier == null ? null : supplier.get() : obj.toString(); |
| } |
| |
| /** |
| * Calls {@link Object#wait(long, int)} for the given Duration. |
| * |
| * @param obj The receiver of the wait call. |
| * @param duration How long to wait. |
| * @throws IllegalArgumentException if the timeout duration is negative. |
| * @throws IllegalMonitorStateException if the current thread is not the owner of the {@code obj}'s monitor. |
| * @throws InterruptedException if any thread interrupted the current thread before or while the current thread was |
| * waiting for a notification. The <em>interrupted status</em> of the current thread is cleared when this |
| * exception is thrown. |
| * @see Object#wait(long, int) |
| * @since 3.12.0 |
| */ |
| public static void wait(final Object obj, final Duration duration) throws InterruptedException { |
| DurationUtils.accept(obj::wait, DurationUtils.zeroIfNull(duration)); |
| } |
| |
| /** |
| * <p>{@code ObjectUtils} instances should NOT be constructed in |
| * standard programming. Instead, the static methods on the class should |
| * be used, such as {@code ObjectUtils.defaultIfNull("a","b");}.</p> |
| * |
| * <p>This constructor is public to permit tools that require a JavaBean |
| * instance to operate.</p> |
| */ |
| public ObjectUtils() { |
| } |
| |
| } |