Update command handler demo and code refinement

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

sentinel-demo/sentinel-demo-command-handler/pom.xml

@@ -5,31 +5,16 @@
     <parent>
         <artifactId>sentinel-demo</artifactId>
         <groupId>com.alibaba.csp</groupId>
-        <version>1.4.2-SNAPSHOT</version>
+        <version>1.5.0-SNAPSHOT</version>
     </parent>
     <modelVersion>4.0.0</modelVersion>
 
     <artifactId>sentinel-demo-command-handler</artifactId>
 
     <dependencies>
-        <dependency>
-            <groupId>com.alibaba.csp</groupId>
-            <artifactId>sentinel-cluster-client-default</artifactId>
-            <version>1.4.2-SNAPSHOT</version>
-        </dependency>
-        <dependency>
-            <groupId>com.alibaba.csp</groupId>
-            <artifactId>sentinel-cluster-server-default</artifactId>
-            <version>1.4.2-SNAPSHOT</version>
-        </dependency>
         <dependency>
             <groupId>com.alibaba.csp</groupId>
             <artifactId>sentinel-transport-simple-http</artifactId>
         </dependency>
-        <dependency>
-            <groupId>org.springframework.boot</groupId>
-            <artifactId>spring-boot-starter-web</artifactId>
-            <version>1.5.17.RELEASE</version>
-        </dependency>
     </dependencies>
 </project>

sentinel-demo/sentinel-demo-command-handler/src/main/java/com/alibaba/csp/sentinel/demo/commandhandler/CommandDemo.java

@@ -15,17 +15,24 @@
  */
 package com.alibaba.csp.sentinel.demo.commandhandler;
 
-import org.springframework.boot.SpringApplication;
-import org.springframework.boot.autoconfigure.SpringBootApplication;
+import com.alibaba.csp.sentinel.init.InitExecutor;
 
 /**
- * @author houyi
- **/
-@SpringBootApplication(scanBasePackages = {"com.alibaba.csp.sentinel"})
-public class Application {
+ * <p>To run this demo, we need to add the {@code sentinel-transport-simple-http} dependency.</p>
+ * <p>
+ * As soon as the CommandCenter has been initialized, we can visit {@code http://ip:commandPort/api}
+ * to see all available command APIs (by default the port is 8719).
+ * We can also visit our customized {@code /echo} command.
+ * </p>
+ *
+ * @author Eric Zhao
+ */
+public class CommandDemo {
 
     public static void main(String[] args) {
-        SpringApplication.run(Application.class, args);
-    }
+        // Only for demo. You don't have to do this in your application.
+        InitExecutor.doInit();
 
+        System.out.println("Sentinel CommandCenter has been initialized");
+    }
 }

sentinel-demo/sentinel-demo-command-handler/src/main/java/com/alibaba/csp/sentinel/demo/commandhandler/EchoCommandHandler.java

@@ -21,26 +21,28 @@ import com.alibaba.csp.sentinel.command.CommandResponse;
 import com.alibaba.csp.sentinel.command.annotation.CommandMapping;
 
 /**
- * Customized CommandHandler
- * This Class is a demo shows how to create a customized CommandHandler
+ * This class is a demo shows how to create and register a customized CommandHandler.
+ *
  * <ul>
- *     <li>1.Create a class which implements the {@link CommandHandler} interface </li>
- *     <li>2.Use a {@link CommandMapping} to specify the url and desc of your CommandHandler </li>
- *     <li>3.Implement your own handle method </li>
- *     <li>4.Add your CommandHandler in com.alibaba.csp.sentinel.command.CommandHandler file which is stored in resources/META-INF/services/ </li>
+ * <li>1. Create a class which implements the {@link CommandHandler} SPI interface</li>
+ * <li>2. Use a {@link CommandMapping} to specify the url and desc of your CommandHandler</li>
+ * <li>3. Implement your own {@code handle} method </li>
+ * <li>4. Add your CommandHandler in {@code com.alibaba.csp.sentinel.command.CommandHandler} file which is stored in
+ * {@code resources/META-INF/services/} directory </li>
  * </ul>
+ *
  * @author houyi
- **/
-@CommandMapping(name = "echo", desc = "echo service")
+ */
+@CommandMapping(name = "echo", desc = "echo command for demo")
 public class EchoCommandHandler implements CommandHandler<String> {
 
     @Override
     public CommandResponse<String> handle(CommandRequest request) {
         String name = request.getParam("name");
-        if(name==null || name.trim().length()==0){
+        if (name == null || name.trim().length() == 0) {
             return CommandResponse.ofSuccess("Tell us what's your name by submit a name parameter");
         }
-        return CommandResponse.ofSuccess("Hello: "+name);
+        return CommandResponse.ofSuccess("Hello: " + name);
     }
 
 }

sentinel-demo/sentinel-demo-command-handler/src/main/java/com/alibaba/csp/sentinel/demo/commandhandler/MainController.java

@@ -1,48 +0,0 @@
-/*
- * Copyright 1999-2019 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.demo.commandhandler;
-
-import com.alibaba.csp.sentinel.SphU;
-import com.alibaba.csp.sentinel.slots.block.BlockException;
-import org.springframework.stereotype.Controller;
-import org.springframework.web.bind.annotation.GetMapping;
-import org.springframework.web.bind.annotation.ResponseBody;
-
-/**
- * @author houyi
- **/
-@Controller
-public class MainController {
-
-    /**
-     * init sentinel
-     * @return pass or block
-     */
-    @GetMapping("/init")
-    public @ResponseBody
-    String init() {
-        String retVal;
-        String resource = "init";
-        try{
-            SphU.entry(resource);
-            retVal = "pass";
-        }catch (BlockException e){
-            retVal = "block";
-        }
-        return retVal;
-    }
-
-}

sentinel-transport/sentinel-transport-common/src/main/java/com/alibaba/csp/sentinel/command/annotation/CommandMapping.java

@@ -27,6 +27,11 @@ public @interface CommandMapping {
 
     String name();
 
+    /**
+     * Get brief description of the command.
+     *
+     * @return brief description of the command
+     * @since 1.5.0
+     */
     String desc();
-
 }

sentinel-transport/sentinel-transport-common/src/main/java/com/alibaba/csp/sentinel/command/handler/ApiCommandHandler.java

@@ -28,10 +28,12 @@ import java.util.Map;
 /**
  * <p>
  * List all available command handlers by request: </br>
- * {@code curl http://localhost:8719/api}
+ * {@code curl http://ip:commandPort/api}
  * </p>
+ *
  * @author houyi
- **/
+ * @since 1.5.0
+ */
 @CommandMapping(name = "api", desc = "get all available command handlers")
 public class ApiCommandHandler implements CommandHandler<String> {