Remove useless global NodeBuilder in Env class

Signed-off-by: Eric Zhao <sczyh16@gmail.com>

sentinel-core/src/main/java/com/alibaba/csp/sentinel/Constants.java

@@ -38,23 +38,27 @@ public final class Constants {
     public final static String ROOT_ID = "machine-root";
     public final static String CONTEXT_DEFAULT_NAME = "sentinel_default_context";
 
+    /**
+     * A virtual resource identifier for total inbound statistics (since 1.5.0).
+     */
     public final static String TOTAL_IN_RESOURCE_NAME = "__total_inbound_traffic__";
 
+    /**
+     * Global ROOT statistic node that represents the universal parent node.
+     */
     public final static DefaultNode ROOT = new EntranceNode(new StringResourceWrapper(ROOT_ID, EntryType.IN),
         new ClusterNode());
 
     /**
-     * Statistics for {@link SystemRule} checking.
+     * Global statistic node for inbound traffic. Usually used for {@link SystemRule} checking.
      */
     public final static ClusterNode ENTRY_NODE = new ClusterNode();
 
     /**
-     * Response time that exceeds TIME_DROP_VALVE will be calculated as TIME_DROP_VALVE.
+     * Response time that exceeds TIME_DROP_VALVE will be calculated as TIME_DROP_VALVE. Default value is 4900 ms.
-     * Default value is 4900 ms
+     * It can be configured by property file or JVM parameter via {@code -Dcsp.sentinel.statistic.max.rt=xxx}.
-     * It can be configured by property file or JVM parameter -Dcsp.sentinel.statistic.max.rt=xxx
-     * See {@link SentinelConfig#statisticMaxRt()}
      */
-    public static int TIME_DROP_VALVE = SentinelConfig.statisticMaxRt();
+    public static final int TIME_DROP_VALVE = SentinelConfig.statisticMaxRt();
 
     /**
      * The global switch for Sentinel.

sentinel-core/src/main/java/com/alibaba/csp/sentinel/Env.java

@@ -16,8 +16,6 @@
 package com.alibaba.csp.sentinel;
 
 import com.alibaba.csp.sentinel.init.InitExecutor;
-import com.alibaba.csp.sentinel.node.DefaultNodeBuilder;
-import com.alibaba.csp.sentinel.node.NodeBuilder;
 
 /**
  * Sentinel Env. This class will trigger all initialization for Sentinel.
@@ -31,7 +29,6 @@ import com.alibaba.csp.sentinel.node.NodeBuilder;
  */
 public class Env {
 
-    public static final NodeBuilder nodeBuilder = new DefaultNodeBuilder();
     public static final Sph sph = new CtSph();
 
     static {

sentinel-core/src/main/java/com/alibaba/csp/sentinel/node/DefaultNodeBuilder.java

@@ -1,37 +0,0 @@
-/*
- * Copyright 1999-2018 Alibaba Group Holding Ltd.
- *
- * 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.csp.sentinel.node;
-
-import com.alibaba.csp.sentinel.slotchain.ResourceWrapper;
-
-/**
- * Default implementation of {@link NodeBuilder}.
- *
- * @author qinan.qn
- */
-public class DefaultNodeBuilder implements NodeBuilder {
-
-    @Override
-    public DefaultNode buildTreeNode(ResourceWrapper id, ClusterNode clusterNode) {
-        return new DefaultNode(id, clusterNode);
-    }
-
-    @Override
-    public ClusterNode buildClusterNode() {
-        return new ClusterNode();
-    }
-
-}

sentinel-core/src/main/java/com/alibaba/csp/sentinel/node/NodeBuilder.java

@@ -22,6 +22,7 @@ import com.alibaba.csp.sentinel.slotchain.ResourceWrapper;
  *
  * @author qinan.qn
  */
+@Deprecated
 public interface NodeBuilder {
 
     /**

sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/clusterbuilder/ClusterBuilderSlot.java

@@ -18,7 +18,6 @@ package com.alibaba.csp.sentinel.slots.clusterbuilder;
 import java.util.HashMap;
 import java.util.Map;
 
-import com.alibaba.csp.sentinel.Env;
 import com.alibaba.csp.sentinel.EntryType;
 import com.alibaba.csp.sentinel.context.Context;
 import com.alibaba.csp.sentinel.context.ContextUtil;
@@ -79,7 +78,7 @@ public class ClusterBuilderSlot extends AbstractLinkedProcessorSlot<DefaultNode>
             synchronized (lock) {
                 if (clusterNode == null) {
                     // Create the cluster node.
-                    clusterNode = Env.nodeBuilder.buildClusterNode();
+                    clusterNode = new ClusterNode();
                     HashMap<ResourceWrapper, ClusterNode> newMap = new HashMap<>(Math.max(clusterNodeMap.size(), 16));
                     newMap.putAll(clusterNodeMap);
                     newMap.put(node.getId(), clusterNode);

sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/nodeselector/NodeSelectorSlot.java

@@ -18,7 +18,6 @@ package com.alibaba.csp.sentinel.slots.nodeselector;
 import java.util.HashMap;
 import java.util.Map;
 
-import com.alibaba.csp.sentinel.Env;
 import com.alibaba.csp.sentinel.context.Context;
 import com.alibaba.csp.sentinel.context.ContextUtil;
 import com.alibaba.csp.sentinel.node.ClusterNode;
@@ -156,7 +155,7 @@ public class NodeSelectorSlot extends AbstractLinkedProcessorSlot<Object> {
             synchronized (this) {
                 node = map.get(context.getName());
                 if (node == null) {
-                    node = Env.nodeBuilder.buildTreeNode(resourceWrapper, null);
+                    node = new DefaultNode(resourceWrapper, null);
                     HashMap<String, DefaultNode> cacheMap = new HashMap<String, DefaultNode>(map.size());
                     cacheMap.putAll(map);
                     cacheMap.put(context.getName(), node);

sentinel-core/src/test/java/com/alibaba/csp/sentinel/node/DefaultNodeBuilderTest.java

@@ -1,84 +0,0 @@
-/*
- * Copyright 1999-2018 Alibaba Group Holding Ltd.
- *
- * 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.csp.sentinel.node;
-
-import com.alibaba.csp.sentinel.EntryType;
-import com.alibaba.csp.sentinel.slotchain.ResourceWrapper;
-import com.alibaba.csp.sentinel.slotchain.StringResourceWrapper;
-import org.junit.Test;
-
-import static org.junit.Assert.*;
-
-/**
- * Test cases for {@link DefaultNodeBuilder}.
- *
- * @author cdfive
- */
-public class DefaultNodeBuilderTest {
-
-    @Test
-    public void testBuildTreeNode() {
-        DefaultNodeBuilder builder = new DefaultNodeBuilder();
-
-        ResourceWrapper id = new StringResourceWrapper("resA", EntryType.IN);
-        ClusterNode clusterNode = new ClusterNode();
-        DefaultNode defaultNode = builder.buildTreeNode(id, clusterNode);
-
-        assertNotNull(defaultNode);
-        assertEquals(id, defaultNode.getId());
-        assertEquals(clusterNode, defaultNode.getClusterNode());
-
-        // verify each call returns a different instance
-        DefaultNode defaultNode2 = builder.buildTreeNode(id, clusterNode);
-        assertNotNull(defaultNode2);
-        assertNotSame(defaultNode, defaultNode2);
-        // now DefaultNode#equals(Object) is not implemented, they are not equal
-        assertNotEquals(defaultNode, defaultNode2);
-    }
-
-    @Test
-    public void testBuildTreeNodeNullClusterNode() {
-        DefaultNodeBuilder builder = new DefaultNodeBuilder();
-
-        ResourceWrapper id = new StringResourceWrapper("resA", EntryType.IN);
-        DefaultNode defaultNode = builder.buildTreeNode(id, null);
-
-        assertNotNull(defaultNode);
-        assertEquals(id, defaultNode.getId());
-        assertNull(defaultNode.getClusterNode());
-
-        // verify each call returns a different instance
-        DefaultNode defaultNode2 = builder.buildTreeNode(id, null);
-        assertNotNull(defaultNode2);
-        assertNotSame(defaultNode, defaultNode2);
-        // now DefaultNode#equals(Object) is not implemented, they are not equal
-        assertNotEquals(defaultNode, defaultNode2);
-    }
-
-    @Test
-    public void testBuildClusterNode() {
-        DefaultNodeBuilder builder = new DefaultNodeBuilder();
-        ClusterNode clusterNode = builder.buildClusterNode();
-        assertNotNull(clusterNode);
-
-        // verify each call returns a different instance
-        ClusterNode clusterNode2 = builder.buildClusterNode();
-        assertNotNull(clusterNode2);
-        assertNotSame(clusterNode, clusterNode2);
-        // as new a ClusterNode instance in DefaultNodeBuilder#buildClusterNode(), they are not equal
-        assertNotEquals(clusterNode, clusterNode2);
-    }
-}