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/*
* Copyright (C) 2007 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.collect;
import com.google.common.base.Function;
import com.google.common.testing.NullPointerTester;
import junit.framework.TestCase;
import java.lang.ref.WeakReference;
/**
* Unit test for {@link Interners}.
*
* @author Kevin Bourrillion
*/
public class InternersTest extends TestCase {
public void testStrong_simplistic() {
String canonical = "a";
String not = new String("a");
Interner<String> pool = Interners.newStrongInterner();
assertSame(canonical, pool.intern(canonical));
assertSame(canonical, pool.intern(not));
}
public void testStrong_null() {
Interner<String> pool = Interners.newStrongInterner();
try {
pool.intern(null);
fail();
} catch (NullPointerException ok) {}
}
public void testWeak_simplistic() {
String canonical = "a";
String not = new String("a");
Interner<String> pool = Interners.newWeakInterner();
assertSame(canonical, pool.intern(canonical));
assertSame(canonical, pool.intern(not));
}
public void testWeak_null() {
Interner<String> pool = Interners.newWeakInterner();
try {
pool.intern(null);
fail();
} catch (NullPointerException ok) {}
}
public void testWeak_afterGC() throws InterruptedException {
Integer canonical = new Integer(5);
Integer not = new Integer(5);
Interner<Integer> pool = Interners.newWeakInterner();
assertSame(canonical, pool.intern(canonical));
WeakReference<Integer> signal = new WeakReference<Integer>(canonical);
canonical = null;
for (int i = 0; i < 3000; i++) {
System.gc();
if (signal.get() == null) { // it was collected
assertSame(not, pool.intern(not));
return;
}
Thread.sleep(1);
}
fail("reference didn't get cleaned up");
}
public void testAsFunction_simplistic() {
String canonical = "a";
String not = new String("a");
Function<String, String> internerFunction =
Interners.asFunction(Interners.<String>newStrongInterner());
assertSame(canonical, internerFunction.apply(canonical));
assertSame(canonical, internerFunction.apply(not));
}
public void testNullPointerExceptions() throws Exception {
new NullPointerTester().testAllPublicStaticMethods(Interners.class);
}
}
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