Example usage for java.lang.reflect Array getLength

Introduction

In this page you can find the example usage for java.lang.reflect Array getLength.

Prototype

@HotSpotIntrinsicCandidate
public static native int getLength(Object array) throws IllegalArgumentException;

Source Link

Document

Returns the length of the specified array object, as an int .

Usage

From source file:Main.java

/**
 * Returns a copy of the given array of size 1 greater than the argument. The last value of the
 * array is left to the default value./*w w w .ja  va2  s. c o m*/
 * 
 * @param array
 *          The array to copy, must not be <code>null</code>.
 * @param newArrayComponentType
 *          If <code>array</code> is <code>null</code>, create a size 1 array of this type.
 * @return A new copy of the array of size 1 greater than the input.
 */
private static Object copyArrayGrow1(final Object array, final Class newArrayComponentType) {
    if (array != null) {
        int arrayLength = Array.getLength(array);
        Object newArray = Array.newInstance(array.getClass().getComponentType(), arrayLength + 1);
        System.arraycopy(array, 0, newArray, 0, arrayLength);
        return newArray;
    }
    return Array.newInstance(newArrayComponentType, 1);
}

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From source file:Main.java

/**
 *  Copies elements of source to dest. If adjust is -1 the element at
 *  colindex is not copied. If adjust is +1 that element is filled with
 *  the Object addition. All the rest of the elements in source are
 *  shifted left or right accordingly when they are copied. If adjust is 0
 *  the addition is copied over the element at colindex.
 *
 *  No checks are perfomed on array sizes and an exception is thrown
 *  if they are not consistent with the other arguments.
 *///from ww w. j  a  v a  2 s . c  o  m
public static void copyAdjustArray(Object source, Object dest, Object addition, int colindex, int adjust) {

    int length = Array.getLength(source);

    if (colindex < 0) {
        System.arraycopy(source, 0, dest, 0, length);

        return;
    }

    System.arraycopy(source, 0, dest, 0, colindex);

    if (adjust == 0) {
        int endcount = length - colindex - 1;

        Array.set(dest, colindex, addition);

        if (endcount > 0) {
            System.arraycopy(source, colindex + 1, dest, colindex + 1, endcount);
        }
    } else if (adjust < 0) {
        int endcount = length - colindex - 1;

        if (endcount > 0) {
            System.arraycopy(source, colindex + 1, dest, colindex, endcount);
        }
    } else {
        int endcount = length - colindex;

        Array.set(dest, colindex, addition);

        if (endcount > 0) {
            System.arraycopy(source, colindex, dest, colindex + 1, endcount);
        }
    }
}

---

From source file:Main.java

/**
 * @param propertyValue node.getProperty value.
 * @return a collection of all the values from a property. If the value is
 *         just a plain "single" value the collection will contain that
 *         single value. If the value is an array of values, all those
 *         values are added to the collection.
 */// ww  w. ja  v  a2  s .com
public static Collection<Object> propertyValueToCollection(Object propertyValue) {
    Set<Object> values = new HashSet<Object>();
    try {
        int length = Array.getLength(propertyValue);
        for (int i = 0; i < length; i++) {
            values.add(Array.get(propertyValue, i));
        }
    } catch (IllegalArgumentException e) {
        values.add(propertyValue);
    }
    return values;
}

---

From source file:Main.java

/**
 * Returns a copy of the given array of size 1 greater than the argument.
 * The last value of the array is left to the default value.
 *
 * @param array The array to copy, must not be {@code null}.
 * @param newArrayComponentType If {@code array} is {@code null}, create a
 * size 1 array of this type.//  w  ww  .j  av  a  2  s .c  om
 * @return A new copy of the array of size 1 greater than the input.
 */
private static Object copyArrayGrow1(final Object array, final Class<?> newArrayComponentType) {
    if (array != null) {
        final int arrayLength = Array.getLength(array);
        final Object newArray = Array.newInstance(array.getClass().getComponentType(), arrayLength + 1);
        System.arraycopy(array, 0, newArray, 0, arrayLength);
        return newArray;
    }
    return Array.newInstance(newArrayComponentType, 1);
}

---

From source file:Main.java

public static void cleanThreadLocals(Thread thread)
        throws NoSuchFieldException, ClassNotFoundException, IllegalArgumentException, IllegalAccessException {
    if (thread == null)
        return;//  w  ww. j  ava  2s . co  m
    Field threadLocalsField = Thread.class.getDeclaredField("threadLocals");
    threadLocalsField.setAccessible(true);

    Class<?> threadLocalMapKlazz = Class.forName("java.lang.ThreadLocal$ThreadLocalMap");
    Field tableField = threadLocalMapKlazz.getDeclaredField("table");
    tableField.setAccessible(true);

    Object fieldLocal = threadLocalsField.get(thread);
    if (fieldLocal == null) {
        return;
    }
    Object table = tableField.get(fieldLocal);

    int threadLocalCount = Array.getLength(table);

    for (int i = 0; i < threadLocalCount; i++) {
        Object entry = Array.get(table, i);
        if (entry != null) {
            Field valueField = entry.getClass().getDeclaredField("value");
            valueField.setAccessible(true);
            Object value = valueField.get(entry);
            if (value != null) {

                if ("java.util.concurrent.ConcurrentLinkedQueue".equals(value.getClass().getName())
                        || "java.util.concurrent.ConcurrentHashMap".equals(value.getClass().getName())) {
                    valueField.set(entry, null);
                }
            }

        }
    }
}

---

From source file:Main.java

public static Object arrayExpandAddElements(Object array, Collection elementsToAdd) {
    Class cl = array.getClass();//  w  w  w. j a  v a  2s.  com
    if (!cl.isArray())
        return null;
    int length = Array.getLength(array);
    int newLength = length + elementsToAdd.size();
    Class componentType = array.getClass().getComponentType();
    Object newArray = Array.newInstance(componentType, newLength);
    System.arraycopy(array, 0, newArray, 0, length);
    int count = 0;
    for (Object element : elementsToAdd) {
        Array.set(newArray, length + count, element);
        count++;
    }
    return newArray;
}

---

From source file:Main.java

/**
 * Checks if the specified collection/array/iterator is empty.
 * <p>/* www .  j av  a 2s  . c o  m*/
 * This method can handles objects as follows
 * <ul>
 * <li>Collection - via collection isEmpty
 * <li>Map - via map isEmpty
 * <li>Array - using array size
 * <li>Iterator - via hasNext
 * <li>Enumeration - via hasMoreElements
 * </ul>
 * <p>
 * Note: This method is named to avoid clashing with
 * {@link #isEmpty(Collection)}.
 * 
 * @param object
 *            the object to get the size of, not null
 * @return true if empty
 * @throws IllegalArgumentException
 *             thrown if object is not recognised or null
 */
public static boolean sizeIsEmpty(Object object) {
    if (object instanceof Collection) {
        return ((Collection<?>) object).isEmpty();
    } else if (object instanceof Map) {
        return ((Map<?, ?>) object).isEmpty();
    } else if (object instanceof Object[]) {
        return ((Object[]) object).length == 0;
    } else if (object instanceof Iterator) {
        return !((Iterator<?>) object).hasNext();
    } else if (object instanceof Enumeration) {
        return !((Enumeration<?>) object).hasMoreElements();
    } else if (object == null) {
        throw new IllegalArgumentException("Unsupported object type: null");
    } else {
        try {
            return Array.getLength(object) == 0;
        } catch (IllegalArgumentException ex) {
            throw new IllegalArgumentException("Unsupported object type: " + object.getClass().getName());
        }
    }
}

---

From source file:Main.java

@SuppressWarnings("rawtypes")
protected static boolean isNullOrEmpty(Object obj) {
    if (obj == null) {
        return true;
    }/*from  w  ww  . j ava  2  s .  co  m*/
    if (obj instanceof String) {
        if (((String) obj).length() == 0) {
            return true;
        }
    }
    if (obj instanceof Collection) {
        if (((Collection) obj).size() == 0) {
            return true;
        }
    }
    if (obj instanceof Map) {
        if (((Map) obj).size() == 0) {
            return true;
        }
    }
    if (isArray(obj)) {
        if (Array.getLength(obj) == 0) {
            return true;
        }
    }
    return false;
}

---

From source file:ArrayExpander.java

public static Object expandAtHead(Object array, int newSize) {
    if (array == null) {
        return null;
    }/*from w w  w  . j  a va  2s. c o  m*/
    Class c = array.getClass();
    if (c.isArray()) {
        int len = Array.getLength(array);
        if (len >= newSize) {
            return array;
        } else {
            Class cc = c.getComponentType();
            Object newArray = Array.newInstance(cc, newSize);
            System.arraycopy(array, 0, newArray, newSize - len, len);
            return newArray;
        }
    } else {
        throw new ClassCastException("need  array");
    }
}

---

From source file:Main.java

@SuppressWarnings("rawtypes")
private static Object joinArrays(Object paramObject1, Object paramObject2) {
    Class localClass = paramObject1.getClass().getComponentType();
    int i = Array.getLength(paramObject1);
    int j = i + Array.getLength(paramObject2);
    Object localObject = Array.newInstance(localClass, j);
    int k = 0;// w w w .  ja va  2  s .  c o m
    while (k < i) {
        Array.set(localObject, k, Array.get(paramObject1, k));
        k++;
    }
    while (k < j) {
        Array.set(localObject, k, Array.get(paramObject2, k - i));
        k++;
    }
    return localObject;
}

---

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