1.Update 调整程序结构。

pom.xml

@@ -15,11 +15,32 @@
             <artifactId>junit</artifactId>
             <version>4.12</version>
         </dependency>
+        <dependency>
+            <groupId>org.powermock</groupId>
+            <artifactId>powermock-core</artifactId>
+            <version>${powermock.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.powermock</groupId>
+            <artifactId>powermock-api-mockito2</artifactId>
+            <version>${powermock.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.powermock</groupId>
+            <artifactId>powermock-module-junit4</artifactId>
+            <version>${powermock.version}</version>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 
     <groupId>moe.cnkirito.sample</groupId>
     <artifactId>consistent-hash</artifactId>
     <version>1.0-SNAPSHOT</version>
+    <properties>
+        <powermock.version>2.0.9</powermock.version>
+    </properties>
     <build>
         <plugins>
             <plugin>
@@ -34,4 +55,4 @@
     </build>
 
 
-</project>
+</project>

src/main/java/moe/cnkirito/consistenthash/AbstractHashStrategy.java

@@ -0,0 +1,17 @@
+package moe.cnkirito.consistenthash;
+
+/**
+ * @author daofeng.xjf
+ * @date 2019/2/15
+ */
+public interface AbstractHashStrategy {
+
+    /**
+     * 根据服务器地址标识符生成在一致性hash环上的hash值
+     *
+     * @param origin 服务器地址标识字符串
+     * @return 一致性hash环上的hash值
+     */
+    int getHashCode(String origin);
+
+}

src/main/java/moe/cnkirito/consistenthash/LoadBalanceable.java

@@ -0,0 +1,22 @@
+package moe.cnkirito.consistenthash;
+
+import moe.cnkirito.consistenthash.bo.Invocation;
+import moe.cnkirito.consistenthash.bo.Server;
+
+import java.util.List;
+
+/**
+ * @author daofeng.xjf
+ * @date 2019/2/16
+ */
+public interface LoadBalanceable {
+
+    /**
+     * 根据数据的hash值在一致性hash环上选择第一个服务器
+     *
+     * @param servers 服务器列表
+     * @param invocation 包含数据hash值的请求
+     * @return 选择到的服务器
+     */
+    Server select(List<Server> servers, Invocation invocation);
+}

src/main/java/moe/cnkirito/consistenthash/Invocation.java → src/main/java/moe/cnkirito/consistenthash/bo/Invocation.java

@@ -1,19 +1,18 @@
-package moe.cnkirito.consistenthash;
+package moe.cnkirito.consistenthash.bo;
 
 /**
  * @author daofeng.xjf
  * @date 2019/2/15
  */
 public class Invocation {
-    public Invocation() {
-    }
+    private String hashKey;
+
+    public Invocation() {}
 
     public Invocation(String hashKey) {
         this.hashKey = hashKey;
     }
 
-    private String hashKey;
-
     public String getHashKey() {
         return hashKey;
     }

src/main/java/moe/cnkirito/consistenthash/Server.java → src/main/java/moe/cnkirito/consistenthash/bo/Server.java

@@ -1,20 +1,19 @@
-package moe.cnkirito.consistenthash;
+package moe.cnkirito.consistenthash.bo;
 
 /**
  * @author daofeng.xjf
  * @date 2019/2/15
  */
 public class Server {
 
-    public Server() {
-    }
+    private String url;
+
+    public Server() {}
 
     public Server(String url) {
         this.url = url;
     }
 
-    private String url;
-
     public String getUrl() {
         return url;
     }

src/main/java/moe/cnkirito/consistenthash/load/balancer/ConsistentHashLoadBalancer.java

@@ -0,0 +1,30 @@
+package moe.cnkirito.consistenthash.load.balancer;
+
+
+import moe.cnkirito.consistenthash.AbstractHashStrategy;
+import moe.cnkirito.consistenthash.bo.Invocation;
+import moe.cnkirito.consistenthash.LoadBalanceable;
+import moe.cnkirito.consistenthash.bo.Server;
+import moe.cnkirito.consistenthash.strategy.FnvHashStrategy;
+import moe.cnkirito.consistenthash.strategy.HashStratetyFactory;
+
+import java.util.List;
+import java.util.Map;
+import java.util.TreeMap;
+
+/**
+ * @author daofeng.xjf
+ * @date 2019/2/15
+ */
+public class ConsistentHashLoadBalancer implements LoadBalanceable {
+
+    private static final AbstractHashStrategy hashStrategy = HashStratetyFactory.getHashStrategy();
+
+    @Override
+    public Server select(List<Server> servers, Invocation invocation) {
+        int invocationHashCode = hashStrategy.getHashCode(invocation.getHashKey());
+        ConsistentHashRing consistentHashRing = ConsistentHashRing.getInstance(servers);
+        return consistentHashRing.locate(invocationHashCode);
+    }
+
+}

src/main/java/moe/cnkirito/consistenthash/load/balancer/ConsistentHashRing.java

@@ -0,0 +1,68 @@
+package moe.cnkirito.consistenthash.load.balancer;
+
+import com.google.common.annotations.VisibleForTesting;
+import moe.cnkirito.consistenthash.AbstractHashStrategy;
+import moe.cnkirito.consistenthash.bo.Server;
+import moe.cnkirito.consistenthash.strategy.FnvHashStrategy;
+import moe.cnkirito.consistenthash.strategy.HashStratetyFactory;
+
+import java.util.List;
+import java.util.Map;
+import java.util.TreeMap;
+
+import static moe.cnkirito.consistenthash.load.balancer.constant.HashRingConstant.VIRTUAL_NODE_SIZE;
+import static moe.cnkirito.consistenthash.load.balancer.constant.HashRingConstant.VIRTUAL_NODE_SUFFIX;
+
+/**
+ * 一致性hash环
+ *
+ * @author dailj
+ * @date 2022/11/25 15:54
+ */
+public class ConsistentHashRing {
+    private static ConsistentHashRing instance;
+    private static TreeMap<Integer, Server> virtualNodeRing;
+    private static AbstractHashStrategy hashStrategy = HashStratetyFactory.getHashStrategy();
+
+    public static ConsistentHashRing getInstance(List<Server> servers) {
+        if (instance == null) {
+            synchronized (ConsistentHashRing.class) {
+                if (instance == null) {
+                    instance = new ConsistentHashRing(servers);
+                }
+            }
+        }
+        return instance;
+    }
+
+    public Server locate(Integer invocationHashCode) {
+        // 向右找到第一个 key
+        Map.Entry<Integer, Server> locateEntry = virtualNodeRing.ceilingEntry(invocationHashCode);
+        if (locateEntry == null) {
+            // 想象成一个环，超过尾部则取第一个 key
+            locateEntry = virtualNodeRing.firstEntry();
+        }
+        return locateEntry.getValue();
+    }
+
+    private ConsistentHashRing(List<Server> servers) {
+        init(servers);
+    }
+
+    private ConsistentHashRing() {}
+
+    private void init(List<Server> servers) {
+        virtualNodeRing = buildConsistentHashRing(servers);
+    }
+
+    private TreeMap<Integer, Server> buildConsistentHashRing(List<Server> servers) {
+        TreeMap<Integer, Server> virtualNodeRing = new TreeMap<>();
+        for (Server server : servers) {
+            for (int i = 0; i < VIRTUAL_NODE_SIZE; i++) {
+                // 新增虚拟节点的方式如果有影响，也可以抽象出一个由物理节点扩展虚拟节点的类
+                virtualNodeRing.put(hashStrategy.getHashCode(server.getUrl() + VIRTUAL_NODE_SUFFIX + i), server);
+            }
+        }
+        return virtualNodeRing;
+    }
+}