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* Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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*/
package com.github.dcevm.test.fields;
import org.junit.After;
import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;
import java.lang.invoke.MethodHandle;
import java.lang.invoke.MethodHandles;
import static com.github.dcevm.test.util.HotSwapTestHelper.__toVersion__;
import static org.junit.Assert.assertEquals;
/**
* Test for replacing field with MethodHandle pointing to it.
*
* Technically, should work for Java 7, but currently is not supported in Java 7.
*
* @author Ivan Dubrov
*/
public class InstanceFieldHandleTest {
// Version 0
public static class A {
public int fieldA;
public int fieldB;
public int getFieldA() {
return -1;
}
}
// Version 1 (fields swapped and new one is added)
public static class A___1 {
public int fieldB;
public int fieldA;
public String fieldC;
public int getFieldA() {
return fieldA;
}
}
// Version 2 (fields removed)
public static class A___2 {
}
// Version 3 (field type changed)
public static class A___3 {
public String fieldA;
public int fieldB;
}
@Before
@After
public void setUp() throws Exception {
__toVersion__(0);
}
@Test
public void testFieldChangeOrder() throws Throwable {
A a = new A();
MethodHandle getter = MethodHandles.publicLookup().findGetter(A.class, "fieldA", int.class);
MethodHandle setter = MethodHandles.publicLookup().findSetter(A.class, "fieldA", int.class);
a.fieldA = 3;
assertEquals(3, getter.invoke(a));
// Swap fields
__toVersion__(1);
assertEquals(3, getter.invoke(a));
setter.invoke(a, 53);
assertEquals(53, a.getFieldA());
assertEquals(53, getter.invoke(a));
}
@Test
public void testFieldRemoved() throws Throwable {
A a = new A();
MethodHandle getter = MethodHandles.publicLookup().findGetter(A.class, "fieldA", int.class);
MethodHandle setter = MethodHandles.publicLookup().findSetter(A.class, "fieldA", int.class);
a.fieldA = 3;
assertEquals(3, getter.invoke(a));
// Remove fieldA
__toVersion__(2);
try {
getter.invoke(a);
Assert.fail("Handle should have been cleared!");
} catch (NullPointerException e) {
// Handle was cleared!
}
try {
setter.invoke(a, 10);
Assert.fail("Handle should have been cleared!");
} catch (NullPointerException e) {
// Handle was cleared!
}
}
@Test
public void testFieldTypeChange() throws Throwable {
A a = new A();
MethodHandle getter = MethodHandles.publicLookup().findGetter(A.class, "fieldA", int.class);
MethodHandle setter = MethodHandles.publicLookup().findSetter(A.class, "fieldA", int.class);
a.fieldA = 3;
assertEquals(3, getter.invoke(a));
// Remove fieldA
__toVersion__(3);
try {
getter.invoke(a);
Assert.fail("Handle should have been cleared!");
} catch (NullPointerException e) {
// Handle was cleared!
}
try {
setter.invoke(a, 10);
Assert.fail("Handle should have been cleared!");
} catch (NullPointerException e) {
// Handle was cleared!
}
}
}