ObjectUtil Class — netty Architecture

Source Code

common/src/main/java/io/netty/util/internal/ObjectUtil.java lines 23–350

public final class ObjectUtil {

    private static final float FLOAT_ZERO = 0.0F;
    private static final double DOUBLE_ZERO = 0.0D;
    private static final long LONG_ZERO = 0L;
    private static final int INT_ZERO = 0;
    private static final short SHORT_ZERO = 0;

    private ObjectUtil() {
    }

    /**
     * Checks that the given argument is not null. If it is, throws {@link NullPointerException}.
     * Otherwise, returns the argument.
     */
    public static <T> T checkNotNull(T arg, String text) {
        if (arg == null) {
            throw new NullPointerException(text);
        }
        return arg;
    }

    /**
     * Check that the given varargs is not null and does not contain elements
     * null elements.
     *
     * If it is, throws {@link NullPointerException}.
     * Otherwise, returns the argument.
     */
    public static <T> T[] deepCheckNotNull(String text, T... varargs) {
        if (varargs == null) {
            throw new NullPointerException(text);
        }

        for (T element : varargs) {
            if (element == null) {
                throw new NullPointerException(text);
            }
        }
        return varargs;
    }

    /**
     * Checks that the given argument is not null. If it is, throws {@link IllegalArgumentException}.
     * Otherwise, returns the argument.
     */
    public static <T> T checkNotNullWithIAE(final T arg, final String paramName) throws IllegalArgumentException {
        if (arg == null) {
            throw new IllegalArgumentException("Param '" + paramName + "' must not be null");
        }
        return arg;
    }

    /**
     * Checks that the given argument is not null. If it is, throws {@link IllegalArgumentException}.
     * Otherwise, returns the argument.
     *
     * @param <T> type of the given argument value.
     * @param name of the parameter, belongs to the exception message.
     * @param index of the array, belongs to the exception message.
     * @param value to check.
     * @return the given argument value.
     * @throws IllegalArgumentException if value is null.
     */
    public static <T> T checkNotNullArrayParam(T value, int index, String name) throws IllegalArgumentException {
        if (value == null) {
            throw new IllegalArgumentException(
                    "Array index " + index + " of parameter '" + name + "' must not be null");
        }
        return value;
    }

    /**
     * Checks that the given argument is strictly positive. If it is not, throws {@link IllegalArgumentException}.
     * Otherwise, returns the argument.
     */
    public static int checkPositive(int i, String name) {
        if (i <= INT_ZERO) {
            throw new IllegalArgumentException(name + " : " + i + " (expected: > 0)");
        }
        return i;