fix bg

hutool-core/src/test/java/cn/hutool/core/util/ReferenceUtilTest.java

@@ -0,0 +1,34 @@
+package cn.hutool.core.util;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.lang.ref.PhantomReference;
+import java.lang.ref.Reference;
+import java.lang.ref.SoftReference;
+import java.lang.ref.WeakReference;
+
+public class ReferenceUtilTest {
+
+	@Test
+	public void createWeakTest(){
+		final Reference<Integer> integerReference = ReferenceUtil.create(ReferenceUtil.ReferenceType.WEAK, 1);
+		Assert.assertTrue(integerReference instanceof WeakReference);
+		Assert.assertEquals(new Integer(1), integerReference.get());
+	}
+
+	@Test
+	public void createSoftTest(){
+		final Reference<Integer> integerReference = ReferenceUtil.create(ReferenceUtil.ReferenceType.SOFT, 1);
+		Assert.assertTrue(integerReference instanceof SoftReference);
+		Assert.assertEquals(new Integer(1), integerReference.get());
+	}
+
+	@Test
+	public void createPhantomTest(){
+		final Reference<Integer> integerReference = ReferenceUtil.create(ReferenceUtil.ReferenceType.PHANTOM, 1);
+		Assert.assertTrue(integerReference instanceof PhantomReference);
+		// get方法永远都返回null，PhantomReference只能用来监控对象的GC状况
+		Assert.assertNull(integerReference.get());
+	}
+}