fix hashCode & equals implementation for AtomicPositiveInteger

Author: beiwei30

dubbo-common/src/main/java/com/alibaba/dubbo/common/utils/AtomicPositiveInteger.java

@@ -167,20 +167,16 @@ public String toString() {
     public int hashCode() {
         final int prime = 31;
         int result = 1;
-        result = prime * result + ((i == null) ? 0 : i.hashCode());
+        result = prime * result + i.hashCode();
         return result;
     }
 
     @Override
     public boolean equals(Object obj) {
         if (this == obj) return true;
-        if (obj == null) return false;
-        if (getClass() != obj.getClass()) return false;
+        if (!(obj instanceof AtomicPositiveInteger)) return false;
         AtomicPositiveInteger other = (AtomicPositiveInteger) obj;
-        if (i == null) {
-            if (other.i != null) return false;
-        } else if (!i.equals(other.i)) return false;
-        return true;
+        return i.intValue() == other.i.intValue();
     }
 
 }

dubbo-common/src/test/java/com/alibaba/dubbo/common/utils/AtomicPositiveIntegerTest.java

@@ -1,18 +1,18 @@
-/*
- * Copyright 1999-2011 Alibaba Group.
- *  
- * 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.
- */
+/*
+ * Copyright 1999-2011 Alibaba Group.
+ *  
+ * 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.alibaba.dubbo.common.utils;
 
 import static org.hamcrest.CoreMatchers.allOf;
@@ -158,4 +158,10 @@ public void test_addAndGet() throws Exception {
         assertEquals(2, get);
         assertEquals(2, i3.get());
     }
+
+    @Test
+    public void test_equals() {
+        assertEquals(new AtomicPositiveInteger(), new AtomicPositiveInteger());
+        assertEquals(new AtomicPositiveInteger(1), new AtomicPositiveInteger(1));
+    }
 }