Example usage for java.lang.reflect Array newInstance

Introduction

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

Prototype

public static Object newInstance(Class<?> componentType, int... dimensions)
        throws IllegalArgumentException, NegativeArraySizeException

Source Link

Document

Creates a new array with the specified component type and dimensions.

Usage

From source file:Main.java

public static void main(String[] args) {

    String str = "This is from java2s.com";

    Class cls = str.getClass();//  w  ww . j av  a 2 s  .  c  om
    boolean arr = cls.isArray();
    System.out.println(arr);

    Object array = Array.newInstance(int.class, 3);

    Class type = array.getClass();
    if (type.isArray()) {
        Class elementType = type.getComponentType();
        System.out.println("Array of: " + elementType);
        System.out.println("Array size: " + Array.getLength(array));
    }
}

From source file:MainClass.java

public static void main(String args[]) {
    Object array = Array.newInstance(int.class, 3);

    int length = Array.getLength(array);
    Random generator = new Random(System.currentTimeMillis());
    for (int i = 0; i < length; i++) {
        int random = generator.nextInt();
        Array.setInt(array, i, random);
    }//from  ww w.jav  a 2 s.  co  m

    for (int i = 0; i < length; i++) {
        int value = Array.getInt(array, i);
        System.out.println("Position: " + i + ", value: " + value);
    }
}

From source file:SampleMultiArrayReflection.java

public static void main(String[] args) {

    // The oneDimA and oneDimB objects are one dimensional int arrays
    // with 5 elements.

    int[] dim1 = { 5 };
    int[] oneDimA = (int[]) Array.newInstance(int.class, dim1);
    int[] oneDimB = (int[]) Array.newInstance(int.class, 5);

    // The twoDimStr object is a 5 X 10 array of String objects.

    int[] dimStr = { 5, 10 };
    String[][] twoDimStr = (String[][]) Array.newInstance(String.class, dimStr);

    // The twoDimA object is an array of 12 int arrays. The tail
    // dimension is not defined. It is equivalent to the array
    // created as follows:
    //    int[][] ints = new int[12][];

    int[] dimA = { 12 };
    int[][] twoDimA = (int[][]) Array.newInstance(int[].class, dimA);
}

From source file:ArrayTrouble.java

public static void main(String... args) {
    Object o = Array.newInstance(int.class, 0);
    int[] i = (int[]) o;
    int[] j = new int[0];
    out.format("i.length = %d, j.length = %d, args.length = %d%n", i.length, j.length, args.length);
    Array.getInt(o, 0); // ArrayIndexOutOfBoundsException
}

From source file:ArrayCreator.java

public static void main(String... args) {
    Matcher m = p.matcher(s);/*  w ww .j a v  a 2s. co  m*/

    if (m.find()) {
        String cName = m.group(1);
        String[] cVals = m.group(2).split("[\\s,]+");
        int n = cVals.length;

        try {
            Class<?> c = Class.forName(cName);
            Object o = Array.newInstance(c, n);
            for (int i = 0; i < n; i++) {
                String v = cVals[i];
                Constructor ctor = c.getConstructor(String.class);
                Object val = ctor.newInstance(v);
                Array.set(o, i, val);
            }

            Object[] oo = (Object[]) o;
            out.format("%s[] = %s%n", cName, Arrays.toString(oo));

            // production code should handle these exceptions more gracefully
        } catch (ClassNotFoundException x) {
            x.printStackTrace();
        } catch (NoSuchMethodException x) {
            x.printStackTrace();
        } catch (IllegalAccessException x) {
            x.printStackTrace();
        } catch (InstantiationException x) {
            x.printStackTrace();
        } catch (InvocationTargetException x) {
            x.printStackTrace();
        }
    }
}

From source file:Main.java

public static <T> T[] insert(T[] array, int index, T element) {
    T[] ret = (T[]) Array.newInstance(array.getClass().getComponentType(), array.length + 1);
    for (int i = 0; i < ret.length; ++i) {
        ret[i] = i < index ? array[i] : (i == index ? element : array[i - 1]);
    }/*w  w w. java  2 s .c  o m*/
    return ret;
}

From source file:Main.java

public static <T> T[] newArray(final Class<T[]> pClass, final int pLength) {
    return pClass.cast(Array.newInstance(pClass.getComponentType(), pLength));
}

From source file:Main.java

public static <U> U[] removeIndex(U[] original, Class<U> originalClass, int element) {
    U[] n = (U[]) Array.newInstance(originalClass, original.length - 1);
    System.arraycopy(original, 0, n, 0, element);
    System.arraycopy(original, element + 1, n, element, original.length - element - 1);
    return n;//from  w  w  w. j a va2  s.c  o  m
}

From source file:Main.java

public static Object toArray(List<?> list, Class<?> componentType) {
    Object result = Array.newInstance(componentType, list.size());
    System.arraycopy(list.toArray(), 0, result, 0, list.size());
    return result;
}

From source file:Main.java

@SuppressWarnings("unchecked")
public static <T> T[] newArray(Class<T> arrayType, int length) {
    return (T[]) Array.newInstance(arrayType, length);
}