17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.util;
27
28 import java.io.IOException;
29 import java.io.InvalidObjectException;
30 import java.io.Serializable;
31 import java.lang.reflect.ParameterizedType;
32 import java.lang.reflect.Type;
33 import java.util.function.BiConsumer;
34 import java.util.function.BiFunction;
35 import java.util.function.Consumer;
36 import java.util.function.Function;
37 import jdk.internal.misc.SharedSecrets;
38
39 /**
40 * Hash table based implementation of the {@code Map} interface. This
41 * implementation provides all of the optional map operations, and permits
42 * {@code null} values and the {@code null} key. (The {@code HashMap}
43 * class is roughly equivalent to {@code Hashtable}, except that it is
44 * unsynchronized and permits nulls.) This class makes no guarantees as to
45 * the order of the map; in particular, it does not guarantee that the order
46 * will remain constant over time.
47 *
48 * <p>This implementation provides constant-time performance for the basic
49 * operations ({@code get} and {@code put}), assuming the hash function
50 * disperses the elements properly among the buckets. Iteration over
51 * collection views requires time proportional to the "capacity" of the
52 * {@code HashMap} instance (the number of buckets) plus its size (the number
53 * of key-value mappings). Thus, it's very important not to set the initial
54 * capacity too high (or the load factor too low) if iteration performance is
55 * important.
56 *
57 * <p>An instance of {@code HashMap} has two parameters that affect its
|
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.util;
27
28 import java.io.IOException;
29 import java.io.InvalidObjectException;
30 import java.io.Serializable;
31 import java.lang.reflect.ParameterizedType;
32 import java.lang.reflect.Type;
33 import java.util.function.BiConsumer;
34 import java.util.function.BiFunction;
35 import java.util.function.Consumer;
36 import java.util.function.Function;
37 import jdk.internal.access.SharedSecrets;
38
39 /**
40 * Hash table based implementation of the {@code Map} interface. This
41 * implementation provides all of the optional map operations, and permits
42 * {@code null} values and the {@code null} key. (The {@code HashMap}
43 * class is roughly equivalent to {@code Hashtable}, except that it is
44 * unsynchronized and permits nulls.) This class makes no guarantees as to
45 * the order of the map; in particular, it does not guarantee that the order
46 * will remain constant over time.
47 *
48 * <p>This implementation provides constant-time performance for the basic
49 * operations ({@code get} and {@code put}), assuming the hash function
50 * disperses the elements properly among the buckets. Iteration over
51 * collection views requires time proportional to the "capacity" of the
52 * {@code HashMap} instance (the number of buckets) plus its size (the number
53 * of key-value mappings). Thus, it's very important not to set the initial
54 * capacity too high (or the load factor too low) if iteration performance is
55 * important.
56 *
57 * <p>An instance of {@code HashMap} has two parameters that affect its
|