add ClassUtilTest (#1318)

infra/common/src/test/java/cn/hippo4j/common/toolkit/ClassUtilTest.java

@@ -0,0 +1,27 @@
+package cn.hippo4j.common.toolkit;
+
+
+import org.junit.Assert;
+import org.junit.Test;
+
+/**
+ * test for {@link ClassUtil}
+ */
+public class ClassUtilTest {
+
+    @Test
+    public void testGetClassLoader(){
+        ClassLoader expectedClassLoader = Thread.currentThread().getContextClassLoader();
+        ClassLoader actualClassLoader = ClassUtil.getClassLoader(ClassUtilTest.class);
+        Assert.assertEquals(expectedClassLoader, actualClassLoader);
+
+        expectedClassLoader = ClassUtilTest.class.getClassLoader();
+        actualClassLoader = ClassUtil.getClassLoader(null);
+        Assert.assertEquals(expectedClassLoader, actualClassLoader);
+
+        expectedClassLoader = ClassLoader.getSystemClassLoader();
+        actualClassLoader = ClassUtil.getClassLoader(String.class);
+        Assert.assertEquals(expectedClassLoader, actualClassLoader);
+    }
+
+}