1 /*
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   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  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 /* @test
  27  * @summary unit tests for java.lang.invoke.MethodHandles
  28  * @run testng/othervm -ea -esa test.java.lang.invoke.ConstantIdentityMHTest
  29  */
  30 package test.java.lang.invoke;
  31 
  32 import java.lang.invoke.MethodHandle;
  33 import java.lang.invoke.MethodHandles;
  34 import java.lang.invoke.MethodType;
  35 import java.util.List;
  36 import static java.lang.invoke.MethodHandles.*;
  37 import static java.lang.invoke.MethodType.*;
  38 import static org.testng.AssertJUnit.*;
  39 import org.testng.annotations.*;
  40 
  41 public class ConstantIdentityMHTest {
  42   
  43     @Test
  44     public void testZero() throws Throwable {
  45         MethodHandle mhz1 =MethodHandles.zero(void.class);
  46         assertEquals("()void", mhz1.type().toString());
  47         MethodHandle mhz2 = MethodHandles.zero(int.class);
  48         assertEquals("()int", mhz2.type().toString());
  49         MethodHandle mhz3 = MethodHandles.zero(Integer.class);
  50         assertEquals("()Integer", mhz3.type().toString());
  51     }
  52 
  53     @Test
  54     @ExpectedExceptions(NullPointerException.class)
  55     public void testZeroNPE() {
  56         MethodHandle mh = MethodHandles.zero(null);
  57     }
  58 
  59     @Test
  60     void testEmpty() throws Throwable {
  61         MethodHandle cat = lookup().findVirtual(String.class, "concat", methodType(String.class, String.class));
  62         assertEquals("xy", (String)cat.invoke("x","y"));
  63         MethodHandle mhEmpty = MethodHandles.empty(cat.type());
  64         assertEquals(null, (String)mhEmpty.invoke("x","y"));
  65     }
  66 
  67     @Test
  68     @ExpectedExceptions(NullPointerException.class)
  69     void testEmptyNPE() {
  70         MethodHandle lenEmptyMH = MethodHandles.empty(null);
  71     }
  72 }