[ISSUE #4182] Add JavaDoc and Comments for eventmesh-admin-rocketmq Module

eventmesh-admin/eventmesh-admin-rocketmq/src/main/java/org/apache/eventmesh/admin/rocketmq/controller/AdminController.java

@@ -28,14 +28,30 @@
 
 import lombok.extern.slf4j.Slf4j;
 
+/**
+ * This class is responsible for managing the admin module.
+ * <p>
+ * It provides a method to run the admin module with the specified {@link HttpServer}
+ * and handles requests related to topics management.
+ */
+
 @Slf4j
 public class AdminController {
 
     public AdminController() {
     }
 
+    /**
+     * Invoke this method to run the admin module.
+     *
+     * @param server A HttpServer is bound to an IP address and port number
+     *               and listens for incoming TCP connections from clients on this address.
+     * @throws IOException
+     * @see HttpServer
+     */
     public void run(HttpServer server) throws IOException {
 
+        // Creates a mapping from API URI path to the exchange handler on this HttpServer.
         server.createContext(TOPIC_MANAGE_PATH, new TopicsHandler());
 
         log.info("EventMesh-Admin Controller server context created successfully");

eventmesh-admin/eventmesh-admin-rocketmq/src/main/java/org/apache/eventmesh/admin/rocketmq/handler/TopicsHandler.java

@@ -39,33 +39,65 @@
 
 import lombok.extern.slf4j.Slf4j;
 
+/**
+ * This class is responsible for handling HTTP requests related to topics.
+ * <p>
+ * It implements the {@link HttpHandler} interface to process incoming requests,
+ * which is used by the {@linkplain com.sun.net.httpserver.HttpServer HttpServer}.
+ * <p>
+ * It uses the {@link RequestMapping} class to match the request URL and the HTTP method.
+ * <p>
+ * It uses the {@link TopicCreateRequest} class to parse the request body
+ * and the {@link TopicResponse} class to create the response.
+ *
+ * @see HttpHandler
+ */
+
 @Slf4j
 public class TopicsHandler implements HttpHandler {
 
+    /**
+     * Handles the HTTP request for creating topics.
+     *
+     * @param httpExchange the exchange containing the request from the client and used to send the response
+     * @throws IOException if an I/O error occurs
+     * @see HttpHandler#handle(HttpExchange)
+     */
     @Override
     public void handle(HttpExchange httpExchange) throws IOException {
 
-        // create a new topic
+        // If the request matches, then create a new topic.
         if (RequestMapping.postMapping(TOPIC_MANAGE_PATH, httpExchange)) {
             createTopicHandler(httpExchange);
             return;
         }
 
+        // Otherwise, it prepares an error response and sends it back to the client.
         OutputStream out = httpExchange.getResponseBody();
         httpExchange.sendResponseHeaders(500, 0);
         String result = String.format("Please check your request url: %s", httpExchange.getRequestURI());
         log.error(result);
+        // Write the response data.
         out.write(result.getBytes(Constants.DEFAULT_CHARSET));
     }
 
+    /**
+     * Handles the creation of a new topic.
+     *
+     * @param httpExchange the exchange containing the request from the client and used to send the response
+     * @throws IOException if an I/O error occurs
+     */
     public void createTopicHandler(HttpExchange httpExchange) throws IOException {
         String result;
         try (OutputStream out = httpExchange.getResponseBody()) {
+            // Parses the request body into a TopicCreateRequest object.
             String params = NetUtils.parsePostBody(httpExchange);
             TopicCreateRequest topicCreateRequest =
                 JsonUtils.parseObject(params, TopicCreateRequest.class);
+            // Gets the topic name from the request body.
             String topic = topicCreateRequest.getTopic();
 
+            // If the topic name is empty, then returns an error message.
             if (StringUtils.isBlank(topic)) {
                 result = "Create topic failed. Parameter topic not found.";
                 log.error(result);
@@ -74,7 +106,7 @@ public void createTopicHandler(HttpExchange httpExchange) throws IOException {
             }
 
             //TBD: A new rocketmq service will be implemented for creating topics
-            TopicResponse topicResponse = null;
+            TopicResponse topicResponse = null; // Temporary variable for topic response
             if (topicResponse != null) {
                 log.info("create a new topic: {}", topic);
                 httpExchange.getResponseHeaders().add(CONTENT_TYPE, APPLICATION_JSON);
@@ -83,12 +115,14 @@ public void createTopicHandler(HttpExchange httpExchange) throws IOException {
                 log.info(result);
                 out.write(result.getBytes(Constants.DEFAULT_CHARSET));
             } else {
+                // If the topic creation fails, then returns an error message.
                 httpExchange.sendResponseHeaders(500, 0);
                 result = TOPIC_ERROR;
                 log.error(result);
                 out.write(result.getBytes(Constants.DEFAULT_CHARSET));
             }
         } catch (Exception e) {
+            // If an exception occurs, then returns an error message.
             httpExchange.getResponseHeaders().add(CONTENT_TYPE, APPLICATION_JSON);
             httpExchange.sendResponseHeaders(500, 0);
             result = TOPIC_ERROR;

eventmesh-admin/eventmesh-admin-rocketmq/src/main/java/org/apache/eventmesh/admin/rocketmq/request/TopicCreateRequest.java

@@ -22,12 +22,35 @@
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 
+/**
+ * A data transfer object (DTO) that represents a request to create a new topic.
+ * <p>
+ * This class provides a convenient way to encapsulate the topic information when creating a new topic.
+ * <p>
+ * Empty or null values will not be included in the serialized JSON.
+ * <p>
+ * Any unknown properties will be ignored when deserializing JSON into this class.
+ * <p>
+ * Example usage:
+ * <pre>
+ * String params = NetUtils.parsePostBody(httpExchange);
+ * TopicCreateRequest topicCreateRequest = JsonUtils.parseObject(params, TopicCreateRequest.class);
+ * String topic = topicCreateRequest.getTopic();
+ * topicCreateRequest.setTopic("UpdatedTopic");
+ * </pre>
+ */
+
 @JsonInclude(JsonInclude.Include.NON_EMPTY)
 @JsonIgnoreProperties(ignoreUnknown = true)
 public class TopicCreateRequest {
 
     private String topic;
 
+    /**
+     * Constructs a new instance of {@link TopicCreateRequest}.
+     *
+     * @param topic the topic for the request
+     */
     @JsonCreator
     public TopicCreateRequest(@JsonProperty("topic") String topic) {
         this.topic = topic;

eventmesh-admin/eventmesh-admin-rocketmq/src/main/java/org/apache/eventmesh/admin/rocketmq/response/TopicResponse.java

@@ -20,6 +20,15 @@
 import com.fasterxml.jackson.annotation.JsonCreator;
 import com.fasterxml.jackson.annotation.JsonProperty;
 
+/**
+ * A data transfer object (DTO) that represents a response containing a topic and its creation time.
+ * <p>
+ * It includes the values returned upon the creation of a new topic, an update to an existing topic,
+ * or the retrieval of a topic's details.
+ * <p>
+ * It is used to encapsulate the topic information being sent to the client from the server.
+ */
+
 public class TopicResponse {
 
     private String topic;

eventmesh-admin/eventmesh-admin-rocketmq/src/main/java/org/apache/eventmesh/admin/rocketmq/util/RequestMapping.java

@@ -23,25 +23,65 @@
 
 import lombok.experimental.UtilityClass;
 
+/**
+ * This class provides utility methods for handling HTTP request mappings.
+ */
+
 @UtilityClass
 public class RequestMapping {
 
+    /**
+     * Performs a POST mapping for a specific URL.
+     *
+     * @param value        the URL pattern to match
+     * @param httpExchange the exchange containing the request from the client and used to send the response
+     * @return {@code true} if the URL pattern matches and the HTTP method is POST, {@code false} otherwise
+     */
     public boolean postMapping(String value, HttpExchange httpExchange) {
         return isUrlMatch(value, httpExchange, HttpMethod.POST.name());
     }
 
+    /**
+     * Performs a GET mapping for a specific URL.
+     *
+     * @param value        the URL pattern to match
+     * @param httpExchange the exchange containing the request from the client and used to send the response
+     * @return {@code true} if the URL pattern matches and the HTTP method is GET, {@code false} otherwise
+     */
     public boolean getMapping(String value, HttpExchange httpExchange) {
         return isUrlMatch(value, httpExchange, HttpMethod.GET.name());
     }
 
+    /**
+     * Performs a PUT mapping for a specific URL.
+     *
+     * @param value        the URL pattern to match
+     * @param httpExchange the exchange containing the request from the client and used to send the response
+     * @return {@code true} if the URL pattern matches and the HTTP method is PUT, {@code false} otherwise
+     */
     public boolean putMapping(String value, HttpExchange httpExchange) {
         return isUrlMatch(value, httpExchange, HttpMethod.PUT.name());
     }
 
+    /**
+     * Performs a DELETE mapping for a specific URL.
+     *
+     * @param value        the URL pattern to match
+     * @param httpExchange the exchange containing the request from the client and used to send the response
+     * @return {@code true} if the URL pattern matches and the HTTP method is DELETE, {@code false} otherwise
+     */
     public boolean deleteMapping(String value, HttpExchange httpExchange) {
         return isUrlMatch(value, httpExchange, HttpMethod.DELETE.name());
     }
 
+    /**
+     * Checks if the URL pattern matches the request URI and the HTTP method is the specified method type.
+     *
+     * @param value        the URL pattern to match
+     * @param httpExchange the exchange containing the request from the client and used to send the response
+     * @param methodType   the HTTP method type to check against
+     * @return {@code true} if the URL pattern matches and the HTTP method is the specified method type, {@code false} otherwise
+     */
     private boolean isUrlMatch(String value, HttpExchange httpExchange, String methodType) {
         if (methodType.equalsIgnoreCase(httpExchange.getRequestMethod())) {
             String requestUri = httpExchange.getRequestURI().getPath();

eventmesh-admin/eventmesh-admin-rocketmq/src/main/java/org/apache/eventmesh/admin/rocketmq/util/UrlMappingPattern.java

@@ -25,6 +25,11 @@
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
+/**
+ * Represents a URL mapping pattern for routing purposes.
+ * The pattern can include variable path parameters or query strings.
+ */
+
 public class UrlMappingPattern {
 
     private static final String URL_PARAMETER_REGEX = "\\{(\\w*?)\\}";
@@ -55,6 +60,13 @@ public String getMappingPattern() {
         return urlMappingPattern.replaceFirst(URL_FORMAT_REGEX, "");
     }
 
+    /**
+     * Extracts path parameters from the given URL and returns a {@link Map} of parameter names to values.
+     *
+     * @param url the URL from which to extract path parameters
+     * @return a {@link Map} containing path parameter names and their corresponding values,
+     *         or null if the URL does not match the defined URL mapping pattern
+     */
     public Map<String, String> extractPathParameterValues(String url) {
         Matcher matcher = compiledUrlMappingPattern.matcher(url);
         if (matcher.matches()) {
@@ -81,6 +93,12 @@ private void acquireParamNames() {
         }
     }
 
+    /**
+     * Extracts parameters from the provided {@link Matcher} object and returns a {@link Map} of parameter names to values.
+     *
+     * @param matcher the Matcher object used to match and capture parameter values
+     * @return a {@link Map} containing parameter names and their corresponding values
+     */
     private Map<String, String> extractParameters(Matcher matcher) {
         Map<String, String> values = new HashMap<>((int) (matcher.groupCount() / 0.75f + 1));
         for (int i = 0; i < matcher.groupCount(); i++) {

eventmesh-runtime/src/main/java/org/apache/eventmesh/runtime/admin/controller/ClientManageController.java

@@ -85,16 +85,26 @@ public ClientManageController(EventMeshTCPServer eventMeshTCPServer,
     }
 
 
+    /**
+     * Method to start the server and perform initialization.
+     *
+     * @throws IOException if an I/O error occurs
+     */
     public void start() throws IOException {
+        // Get the server's admin port.
         int port = eventMeshTCPServer.getEventMeshTCPConfiguration().getEventMeshServerAdminPort();
+        // Create an HTTP server and bind it to the specified port.
         HttpServer server = HttpServer.create(new InetSocketAddress(port), 0);
 
         HttpHandlerManager httpHandlerManager = new HttpHandlerManager();
 
-        //todo Optimized for automatic injection
+        //TODO: Optimized for automatic injection
+
+        // Initialize the client handler and register it with the HTTP handler manager.
         initClientHandler(eventMeshTCPServer, eventMeshHTTPServer,
             eventMeshGrpcServer, eventMeshRegistry, httpHandlerManager);
 
+        // Register the handlers from the HTTP handler manager with the HTTP server.
         httpHandlerManager.registerHttpHandler(server);
         AdminController adminController = new AdminController();
         adminController.run(server);