Implement the Arrays#copyOf family

... as introduced in Java 6.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

classpath/java/util/Arrays.java

@@ -10,6 +10,8 @@
 
 package java.util;
 
+import java.lang.reflect.Array;
+
 public class Arrays {
   private Arrays() { }
 
@@ -348,4 +350,76 @@ public class Arrays {
     }
   }
 
+  public static boolean[] copyOf(boolean[] array, int newLength) {
+    boolean[] result = new boolean[newLength];
+    int length = array.length > newLength ? newLength : array.length;
+    System.arraycopy(array, 0, result, 0, length);
+    return result;
+  }
+
+  public static byte[] copyOf(byte[] array, int newLength) {
+    byte[] result = new byte[newLength];
+    int length = array.length > newLength ? newLength : array.length;
+    System.arraycopy(array, 0, result, 0, length);
+    return result;
+  }
+
+  public static char[] copyOf(char[] array, int newLength) {
+    char[] result = new char[newLength];
+    int length = array.length > newLength ? newLength : array.length;
+    System.arraycopy(array, 0, result, 0, length);
+    return result;
+  }
+
+  public static double[] copyOf(double[] array, int newLength) {
+    double[] result = new double[newLength];
+    int length = array.length > newLength ? newLength : array.length;
+    System.arraycopy(array, 0, result, 0, length);
+    return result;
+  }
+
+  public static float[] copyOf(float[] array, int newLength) {
+    float[] result = new float[newLength];
+    int length = array.length > newLength ? newLength : array.length;
+    System.arraycopy(array, 0, result, 0, length);
+    return result;
+  }
+
+  public static int[] copyOf(int[] array, int newLength) {
+    int[] result = new int[newLength];
+    int length = array.length > newLength ? newLength : array.length;
+    System.arraycopy(array, 0, result, 0, length);
+    return result;
+  }
+
+  public static long[] copyOf(long[] array, int newLength) {
+    long[] result = new long[newLength];
+    int length = array.length > newLength ? newLength : array.length;
+    System.arraycopy(array, 0, result, 0, length);
+    return result;
+  }
+
+  public static short[] copyOf(short[] array, int newLength) {
+    short[] result = new short[newLength];
+    int length = array.length > newLength ? newLength : array.length;
+    System.arraycopy(array, 0, result, 0, length);
+    return result;
+  }
+
+  public static <T> T[] copyOf(T[] array, int newLength) {
+    Class<?> clazz = array.getClass().getComponentType();
+    T[] result = (T[])Array.newInstance(clazz, newLength);
+    int length = array.length > newLength ? newLength : array.length;
+    System.arraycopy(array, 0, result, 0, length);
+    return result;
+  }
+
+  public static <T, U> T[] copyOf(U[] array, int newLength,
+    Class<? extends T[]> newType)
+  {
+    T[] result = (T[])Array.newInstance(newType.getComponentType(), newLength);
+    int length = array.length > newLength ? newLength : array.length;
+    System.arraycopy(array, 0, result, 0, length);
+    return result;
+  }
 }

test/Arrays.java

@@ -130,6 +130,13 @@ public class Arrays {
       java.util.Arrays.hashCode((Object[])null);
     }
 
+    { String[] list = new String[] { "Hello", "World", "!" };
+      Object[] result = java.util.Arrays.copyOf(list, 2, Object[].class);
+      expect(list[1] == result[1]);
+      expect(result.length == 2);
+      expect(result.getClass().getComponentType() == Object.class);
+    }
+
     testSort();
   }
 }