Create a typesafe copy of a raw map. : Generic Collections « Generics « Java Tutorial

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import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

 * @since 4.37
 * @author Jaroslav Tulach

public class Utils {

   * Create a typesafe copy of a raw map.
   * @param rawMap an unchecked map
   * @param keyType the desired supertype of the keys
   * @param valueType the desired supertype of the values
   * @param strict true to throw a <code>ClassCastException</code> if the raw map has an invalid key or value,
   *               false to skip over such map entries (warnings may be logged)
   * @return a typed map guaranteed to contain only keys and values assignable
   *         to the named types (or they may be null)
   * @throws ClassCastException if some key or value in the raw map was not well-typed, and only if <code>strict</code> was true
  public static <K,V> Map<K,V> checkedMapByCopy(Map rawMap, Class<K> keyType, Class<V> valueType, boolean strict) throws ClassCastException {
      Map<K,V> m2 = new HashMap<K,V>(rawMap.size() * 4 / 3 + 1);
      Iterator it = rawMap.entrySet().iterator();
      while (it.hasNext()) {
          Map.Entry e = (Map.Entry);
          try {
              m2.put(keyType.cast(e.getKey()), valueType.cast(e.getValue()));
          } catch (ClassCastException x) {
              if (strict) {
                  throw x;
              } else {
                  System.out.println("not assignable");
      return m2;

12.2.Generic Collections
12.2.1.Generics and Collections: ArrayList
12.2.2.Arrays: Storing class objects in Array as data items
12.2.3.Using Generic Comparable interface
12.2.4.A generic first-in, first-out bounded collection of objects
12.2.5.A list declared to hold objects of a type T can also hold objects that extend from T.
12.2.6.Utilities for generic ArrayList
12.2.7.Your own tree with generic user object
12.2.8.Generic to list
12.2.9.Create a typesafe copy of a raw list.
12.2.10.Create a typesafe copy of a raw map.
12.2.11.Create a typesafe filter of an unchecked iterator.
12.2.12.Create a typesafe view over an underlying raw set.
12.2.13.Create a typesafe view over an underlying raw map.
12.2.14.Create a typesafe filter of an unchecked enumeration.