start code cleanup

Author: Crim

src/main/java/org/sourcelab/kafka/connect/apiclient/ApiClient.java

@@ -6,6 +6,7 @@
 import org.sourcelab.kafka.connect.apiclient.request.Request;
 import org.sourcelab.kafka.connect.apiclient.request.RequestErrorResponse;
 import org.sourcelab.kafka.connect.apiclient.request.delete.DeleteConnector;
+import org.sourcelab.kafka.connect.apiclient.request.dto.ConnectorDefinition;
 import org.sourcelab.kafka.connect.apiclient.request.dto.ConnectorPlugin;
 import org.sourcelab.kafka.connect.apiclient.request.dto.ConnectorPluginConfigDefinition;
 import org.sourcelab.kafka.connect.apiclient.request.dto.ConnectorPluginConfigValidationResults;
@@ -20,7 +21,6 @@
 import org.sourcelab.kafka.connect.apiclient.request.get.GetConnectorTaskStatus;
 import org.sourcelab.kafka.connect.apiclient.request.get.GetConnectorTasks;
 import org.sourcelab.kafka.connect.apiclient.request.get.GetConnectors;
-import org.sourcelab.kafka.connect.apiclient.request.dto.ConnectorDefinition;
 import org.sourcelab.kafka.connect.apiclient.request.post.PostConnector;
 import org.sourcelab.kafka.connect.apiclient.request.post.PostConnectorRestart;
 import org.sourcelab.kafka.connect.apiclient.request.post.PostConnectorTaskRestart;
@@ -37,6 +37,11 @@
 import java.util.Collection;
 import java.util.Map;
 
+/**
+ * API Client for interacting with the Kafka-Connect Rest Endpoint.
+ * Official Rest Endpoint documentation can be found here:
+ *   https://docs.confluent.io/current/connect/restapi.html
+ */
 public class ApiClient {
     private static final Logger logger = LoggerFactory.getLogger(ApiClient.class);
 
@@ -76,49 +81,32 @@ public ApiClient(final Configuration configuration, final RestClient restClient)
         this.restClient = restClient;
     }
 
-    private <T> T submitRequest(final Request<T> request) {
-        // Submit request
-        final RestResponse restResponse = getRestClient().submitRequest(request);
-        final int responseCode = restResponse.getHttpCode();
-        String responseStr = restResponse.getResponseStr();
-
-        // If we have a valid response
-        logger.info("Response: {}", restResponse);
-
-        // Check for invalid http status codes
-        if (responseCode >= 200 && responseCode < 300) {
-            // These response codes have no values
-            if ((responseCode == 204 || responseCode == 205) && responseStr == null) {
-                // Avoid NPE
-                responseStr = "";
-            }
-
-            try {
-                return request.parseResponse(responseStr);
-            } catch (final IOException exception) {
-                throw new RuntimeException(exception.getMessage(), exception);
-            }
-        }
-
-        // Attempt to parse error response
-        try {
-            final RequestErrorResponse errorResponse = JacksonFactory.newInstance().readValue(responseStr, RequestErrorResponse.class);
-            throw new InvalidRequestException(errorResponse.getMessage(), errorResponse.getErrorCode());
-        } catch (IOException e) {
-            // swallow
-        }
-        throw new InvalidRequestException("Invalid response from server: " + responseStr, restResponse.getHttpCode());
-
-    }
-
+    /**
+     * Get a list of active connectors.
+     * https://docs.confluent.io/current/connect/restapi.html#get--connectors
+     *
+     * @return Collection of connector names currently deployed.
+     */
     public Collection<String> getConnectors() {
         return submitRequest(new GetConnectors());
     }
 
+    /**
+     * Get information about the connector.
+     * https://docs.confluent.io/current/connect/restapi.html#get--connectors-(string-name)
+     * @param connectorName Name of connector.
+     * @return Connector details.
+     */
     public ConnectorDefinition getConnector(final String connectorName) {
         return submitRequest(new GetConnector(connectorName));
     }
 
+    /**
+     * Get the configuration for the connector.
+     * https://docs.confluent.io/current/connect/restapi.html#get--connectors-(string-name)-config
+     * @param connectorName Name of connector.
+     * @return Configuration for connector.
+     */
     public Map<String, String> getConnectorConfig(final String connectorName) {
         return submitRequest(new GetConnectorConfig(connectorName));
     }
@@ -260,10 +248,40 @@ public ConnectorPluginConfigValidationResults validateConnectorPluginConfig(fina
         );
     }
 
-    /**
-     * package protected for access in tests.
-     * @return Rest Client.
-     */
+    private <T> T submitRequest(final Request<T> request) {
+        // Submit request
+        final RestResponse restResponse = getRestClient().submitRequest(request);
+        final int responseCode = restResponse.getHttpCode();
+        String responseStr = restResponse.getResponseStr();
+
+        // If we have a valid response
+        logger.info("Response: {}", restResponse);
+
+        // Check for invalid http status codes
+        if (responseCode >= 200 && responseCode < 300) {
+            // These response codes have no values
+            if ((responseCode == 204 || responseCode == 205) && responseStr == null) {
+                // Avoid NPE
+                responseStr = "";
+            }
+
+            try {
+                return request.parseResponse(responseStr);
+            } catch (final IOException exception) {
+                throw new RuntimeException(exception.getMessage(), exception);
+            }
+        }
+
+        // Attempt to parse error response
+        try {
+            final RequestErrorResponse errorResponse = JacksonFactory.newInstance().readValue(responseStr, RequestErrorResponse.class);
+            throw new InvalidRequestException(errorResponse.getMessage(), errorResponse.getErrorCode());
+        } catch (IOException e) {
+            // swallow
+        }
+        throw new InvalidRequestException("Invalid response from server: " + responseStr, restResponse.getHttpCode());
+    }
+
     private RestClient getRestClient() {
         // If we haven't initialized.
         if (!isInitialized) {

src/main/java/org/sourcelab/kafka/connect/apiclient/request/JacksonFactory.java

@@ -3,16 +3,11 @@
 import com.fasterxml.jackson.databind.DeserializationFeature;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.PropertyNamingStrategy;
-import com.fasterxml.jackson.dataformat.xml.JacksonXmlModule;
-import com.fasterxml.jackson.dataformat.xml.XmlMapper;
-import com.fasterxml.jackson.datatype.joda.JodaModule;
-
-import java.text.SimpleDateFormat;
 
 /**
  * Creates properly configured Jackson XML Mapper instances.
  */
-public class JacksonFactory {
+public final class JacksonFactory {
 
     /**
      * Holds our jackson singleton mapper.  ObjectMapper is defined as being

src/main/java/org/sourcelab/kafka/connect/apiclient/request/Request.java

@@ -1,11 +1,10 @@
 package org.sourcelab.kafka.connect.apiclient.request;
 
 import java.io.IOException;
-import java.util.Collection;
-import java.util.Map;
 
 /**
  * Interface for all Requests to implement.
+ * @param <T> return type of request.
  */
 public interface Request<T> {
 
@@ -24,5 +23,11 @@ public interface Request<T> {
      */
     Object getRequestBody();
 
+    /**
+     * Parse the rest service's response into a concrete object.
+     * @param responseStr The servers response in string format.
+     * @return A concrete object representing the result.
+     * @throws IOException on parsing errors.
+     */
     T parseResponse(final String responseStr) throws IOException;
 }

src/main/java/org/sourcelab/kafka/connect/apiclient/request/RequestErrorResponse.java

@@ -1,7 +1,10 @@
 package org.sourcelab.kafka.connect.apiclient.request;
 
-public class RequestErrorResponse {
-    private int errorCode;
+/**
+ * Represents an error response from the rest service.
+ */
+public final class RequestErrorResponse {
+    private int errorCode = 0;
     private String message;
 
     public int getErrorCode() {

src/main/java/org/sourcelab/kafka/connect/apiclient/request/RequestMethod.java

@@ -1,5 +1,8 @@
 package org.sourcelab.kafka.connect.apiclient.request;
 
+/**
+ * Represents the possible request types.
+ */
 public enum RequestMethod {
     DELETE,
     GET,

src/main/java/org/sourcelab/kafka/connect/apiclient/request/delete/DeleteConnector.java

@@ -1,20 +1,29 @@
 package org.sourcelab.kafka.connect.apiclient.request.delete;
 
 import com.sun.xml.internal.rngom.util.Uri;
-import org.sourcelab.kafka.connect.apiclient.request.delete.DeleteRequest;
 
 import java.io.IOException;
 
-public class DeleteConnector implements DeleteRequest<Boolean> {
-    private final String name;
+/**
+ * Defines a request to delete a connector.
+ */
+public final class DeleteConnector implements DeleteRequest<Boolean> {
+    private final String connectorName;
 
-    public DeleteConnector(final String name) {
-        this.name = name;
+    /**
+     * Constructor.
+     * @param connectorName Name of the connector.
+     */
+    public DeleteConnector(final String connectorName) {
+        if (connectorName == null) {
+            throw new NullPointerException("connectorName parameter may not be null!");
+        }
+        this.connectorName = connectorName;
     }
 
     @Override
     public String getApiEndpoint() {
-        return "/connectors/" + Uri.escapeDisallowedChars(name);
+        return "/connectors/" + Uri.escapeDisallowedChars(connectorName);
     }
 
     @Override

src/main/java/org/sourcelab/kafka/connect/apiclient/request/delete/DeleteRequest.java

@@ -3,6 +3,10 @@
 import org.sourcelab.kafka.connect.apiclient.request.Request;
 import org.sourcelab.kafka.connect.apiclient.request.RequestMethod;
 
+/**
+ * Defines interface for DELETE requests.
+ * @param <T> Defines the return type of the request.
+ */
 public interface DeleteRequest<T> extends Request<T> {
     @Override
     default RequestMethod getRequestMethod() {

src/main/java/org/sourcelab/kafka/connect/apiclient/request/dto/ConnectorDefinition.java

@@ -3,7 +3,10 @@
 import java.util.List;
 import java.util.Map;
 
-public class ConnectorDefinition {
+/**
+ * Represents a Connector.
+ */
+public final class ConnectorDefinition {
     private String name;
     private String type;
     private Map<String, String> config;
@@ -35,7 +38,10 @@ public String toString() {
             + '}';
     }
 
-    private static class TaskDefinition {
+    /**
+     * Represents a Task.
+     */
+    private static final class TaskDefinition {
         private String connector;
         private int task;
 

src/main/java/org/sourcelab/kafka/connect/apiclient/request/dto/ConnectorPlugin.java

@@ -5,7 +5,7 @@
 /**
  * Represents details about a Connector Plugin.
  */
-public class ConnectorPlugin {
+public final class ConnectorPlugin {
     @JsonAlias("class")
     private String className;
     private String type;

src/main/java/org/sourcelab/kafka/connect/apiclient/request/dto/ConnectorPluginConfigDefinition.java

@@ -7,7 +7,7 @@
 /**
  * Defines a Connector Plugin Configuration.
  */
-public class ConnectorPluginConfigDefinition {
+public final class ConnectorPluginConfigDefinition {
     private final String name;
     private final Map<String, String> config;