SUBMARINE-1349. Fix the syntax error reported in sonarcloud, add init value for kind in XGboostjobList.java and make some class to be singleton.

Author: hhcs9527

submarine-server/server-core/src/main/java/org/apache/submarine/server/manager/ModelManager.java

@@ -56,13 +56,12 @@ private ModelManager(Submitter submitter, ModelVersionService modelVersionServic
    *
    * @return object
    */
+  private static class ModelManagerHolder {
+    private static ModelManager manager = new ModelManager(SubmitterManager.loadSubmitter(), ModelVersionService.getInstance());
+  }
+
   public static ModelManager getInstance() {
-    if (manager == null) {
-      synchronized (ModelManager.class) {
-        manager = new ModelManager(SubmitterManager.loadSubmitter(), new ModelVersionService());
-      }
-    }
-    return manager;
+    return ModelManager.ModelManagerHolder.manager;
   }
 
   /**
@@ -141,7 +140,7 @@ private void setServeInfo(ServeSpec spec, ModelVersionEntity modelVersion){
   }
 
   private void transferDescription(ServeSpec spec) {
-    Client s3Client = new Client();
+    Client s3Client = Client.getInstance();
     String modelUniquePath = String.format("%s-%d-%s",
         spec.getModelName(), spec.getModelVersion(), spec.getModelId());
     String res  = new String(s3Client.downloadArtifact(String.format("registry/%s/%s/%d/description.json",

submarine-server/server-core/src/main/java/org/apache/submarine/server/manager/ModelVersionManager.java

@@ -50,12 +50,13 @@ public class ModelVersionManager {
    *
    * @return object
    */
-  public static synchronized ModelVersionManager getInstance() {
-    if (manager == null) {
-      manager = new ModelVersionManager(new ModelVersionService(), new ModelVersionTagService(),
-          new Client());
-    }
-    return manager;
+  private static class ModelVersionManagerHolder {
+    private static ModelVersionManager manager = new ModelVersionManager(ModelVersionService.getInstance(), new ModelVersionTagService(),
+    Client.getInstance());
+  }
+
+  public static ModelVersionManager getInstance() {
+    return ModelVersionManager.ModelVersionManagerHolder.manager;
   }
 
   @VisibleForTesting

submarine-server/server-core/src/main/java/org/apache/submarine/server/manager/RegisteredModelManager.java

@@ -37,7 +37,6 @@
  * Registered model manager.
  */
 public class RegisteredModelManager {
-  private static RegisteredModelManager manager;
   /* Registered model service */
   private final RegisteredModelService registeredModelService;
 
@@ -54,12 +53,14 @@ public class RegisteredModelManager {
    *
    * @return object
    */
-  public static synchronized RegisteredModelManager getInstance() {
-    if (manager == null) {
-      manager = new RegisteredModelManager(new RegisteredModelService(), new ModelVersionService(),
-          new RegisteredModelTagService(), new Client());
-    }
-    return manager;
+
+  private static class RegisteredModelManagerHolder {
+    private static RegisteredModelManager manager = new RegisteredModelManager(RegisteredModelService.getInstance(), ModelVersionService.getInstance(),
+    RegisteredModelTagService.getInstance(), Client.getInstance());
+  }
+
+  public static RegisteredModelManager getInstance() {
+    return RegisteredModelManager.RegisteredModelManagerHolder.manager;
   }
 
   @VisibleForTesting

submarine-server/server-core/src/main/java/org/apache/submarine/server/rest/ExperimentRestApi.java

@@ -58,7 +58,7 @@
 @Produces({MediaType.APPLICATION_JSON + "; " + RestConstants.CHARSET_UTF8})
 public class ExperimentRestApi {
   private ExperimentManager experimentManager = ExperimentManager.getInstance();
-  private final Client minioClient = new Client();
+  private final Client minioClient = Client.getInstance();
 
   @VisibleForTesting
   public void setExperimentManager(ExperimentManager experimentManager) {

submarine-server/server-core/src/main/java/org/apache/submarine/server/s3/Client.java

@@ -26,6 +26,8 @@
 import java.util.List;
 import java.util.Stack;
 import javax.ws.rs.core.Response;
+import java.util.Map;
+import java.util.HashMap;
 
 import io.minio.CopyObjectArgs;
 import io.minio.CopySource;
@@ -43,19 +45,38 @@
 
 public class Client {
   public MinioClient minioClient;
+  public static Map<String,MinioClient> minioClientFactory = new HashMap<String, MinioClient>();
+  public static Map<String,Client> clientFactory = new HashMap<String, Client>();
+
+  public static Client getClient(String endpoint) {
+      Client client = clientFactory.get(endpoint);
+      Map<String,Client> clientLocalFactory = clientFactory;
+
+      if (client == null) {
+          synchronized(Client.class) {
+              if (client == null) {
+                  client = new Client(endpoint);
+                  clientLocalFactory.put(endpoint, client);
+                  clientFactory = clientLocalFactory;
+              }
+          }
+      }
+      return client;
+  }
 
-  public Client() {
-    minioClient = MinioClient.builder()
-            .endpoint(S3Constants.ENDPOINT)
-            .credentials(S3Constants.ACCESSKEY, S3Constants.SECRETKEY)
-            .build();
+  public static Client getInstance() {
+    return getClient(S3Constants.ENDPOINT);
+  }
+
+  public static Client getInstance(String endpoint) {
+    return getClient(endpoint);
   }
 
-  public Client(String endpoint) {
+  private Client(String endpoint) {
     minioClient = MinioClient.builder()
-        .endpoint(endpoint)
-        .credentials(S3Constants.ACCESSKEY, S3Constants.SECRETKEY)
-        .build();
+                    .endpoint(endpoint)
+                    .credentials(S3Constants.ACCESSKEY, S3Constants.SECRETKEY)
+                    .build();
   }
 
   /**

submarine-server/server-core/src/test/java/org/apache/submarine/server/rest/ModelVersionRestApiTest.java

@@ -55,9 +55,9 @@ public class ModelVersionRestApiTest {
   private final String modelVersionModelType = "experiment_123";
   private final String modelVersionTag = "testTag";
 
-  private final RegisteredModelService registeredModelService = new RegisteredModelService();
+  private final RegisteredModelService registeredModelService = RegisteredModelService.getInstance();
 
-  private final ModelVersionService modelVersionService = new ModelVersionService();
+  private final ModelVersionService modelVersionService = ModelVersionService.getInstance();
 
   private static final GsonBuilder gsonBuilder = new GsonBuilder()
       .registerTypeAdapter(ExperimentId.class, new ExperimentIdSerializer())

submarine-server/server-core/src/test/java/org/apache/submarine/server/rest/RegisteredModelRestApiTest.java

@@ -39,7 +39,7 @@
 import org.apache.submarine.server.utils.gson.ExperimentIdSerializer;
 
 public class RegisteredModelRestApiTest {
-  private final RegisteredModelService registeredModelService = new RegisteredModelService();
+  private final RegisteredModelService registeredModelService = RegisteredModelService.getInstance();
   private final String registeredModelName = "testRegisteredModel";
   private final String newRegisteredModelName = "newTestRegisteredModel";
   private final String registeredModelDescription = "test registered model description";

submarine-server/server-core/src/test/java/org/apache/submarine/server/s3/ClientTest.java

@@ -27,7 +27,7 @@
 
 
 public class ClientTest {
-  private final Client client = new Client("http://localhost:9000");
+  private final Client client = Client.getInstance("http://localhost:9000");
   private final String testExperimentId = "experiment-sample";
 
   @After

submarine-server/server-database/src/main/java/org/apache/submarine/server/database/model/service/ModelVersionService.java

@@ -30,6 +30,13 @@
 import java.util.List;
 
 public class ModelVersionService {
+  private static class ModelVersionServiceHolder {
+    private static ModelVersionService service = new ModelVersionService();
+  }
+
+  public static ModelVersionService getInstance() {
+    return ModelVersionService.ModelVersionServiceHolder.service;
+  }
 
   private static final Logger LOG = LoggerFactory.getLogger(ModelVersionService.class);
 

submarine-server/server-database/src/main/java/org/apache/submarine/server/database/model/service/RegisteredModelService.java

@@ -31,6 +31,14 @@
 
 public class RegisteredModelService {
 
+  private static class RegisteredModelServiceHolder {
+    private static RegisteredModelService service = new RegisteredModelService();
+  }
+
+  public static RegisteredModelService getInstance() {
+    return RegisteredModelService.RegisteredModelServiceHolder.service;
+  }
+
   private static final Logger LOG = LoggerFactory.getLogger(RegisteredModelService.class);
 
   public List<RegisteredModelEntity> selectAll() throws SubmarineRuntimeException {

submarine-server/server-database/src/main/java/org/apache/submarine/server/database/model/service/RegisteredModelTagService.java

@@ -28,6 +28,13 @@
 import org.slf4j.LoggerFactory;
 
 public class RegisteredModelTagService {
+  private static class RegisteredModelTagServiceHolder {
+    private static RegisteredModelTagService service = new RegisteredModelTagService();
+  }
+
+  public static RegisteredModelTagService getInstance() {
+    return RegisteredModelTagService.RegisteredModelTagServiceHolder.service;
+  }
 
   private static final Logger LOG = LoggerFactory.getLogger(RegisteredModelTagService.class);
 

submarine-server/server-database/src/test/java/org/apache/submarine/server/database/model/ModelVersionTagTest.java

@@ -33,8 +33,8 @@
 
 public class ModelVersionTagTest {
   private static final Logger LOG = LoggerFactory.getLogger(ModelVersionTagTest.class);
-  RegisteredModelService registeredModelService = new RegisteredModelService();
-  ModelVersionService modelVersionService = new ModelVersionService();
+  RegisteredModelService registeredModelService = RegisteredModelService.getInstance();
+  ModelVersionService modelVersionService = ModelVersionService.getInstance();
   ModelVersionTagService modelVersionTagService = new ModelVersionTagService();
 
 

submarine-server/server-database/src/test/java/org/apache/submarine/server/database/model/ModelVersionTest.java

@@ -31,8 +31,8 @@
 import org.apache.submarine.server.database.model.service.RegisteredModelService;
 
 public class ModelVersionTest {
-  RegisteredModelService registeredModelService = new RegisteredModelService();
-  ModelVersionService modelVersionService = new ModelVersionService();
+  RegisteredModelService registeredModelService = RegisteredModelService.getInstance();
+  ModelVersionService modelVersionService = ModelVersionService.getInstance();
 
   @After
   public void cleanAll() {

submarine-server/server-database/src/test/java/org/apache/submarine/server/database/model/RegisteredModelServiceTest.java

@@ -29,7 +29,7 @@
 import java.util.List;
 
 public class RegisteredModelServiceTest {
-  RegisteredModelService registeredModelService = new RegisteredModelService();
+  RegisteredModelService registeredModelService = RegisteredModelService.getInstance();
 
   @After
   public void cleanAll() {

submarine-server/server-database/src/test/java/org/apache/submarine/server/database/model/RegisteredModelTagServiceTest.java

@@ -31,8 +31,8 @@
 
 public class RegisteredModelTagServiceTest {
   private static final Logger LOG = LoggerFactory.getLogger(RegisteredModelTagServiceTest.class);
-  RegisteredModelService registeredModelService = new RegisteredModelService();
-  RegisteredModelTagService registeredModelTagService = new RegisteredModelTagService();
+  RegisteredModelService registeredModelService = RegisteredModelService.getInstance();
+  RegisteredModelTagService registeredModelTagService = RegisteredModelTagService.getInstance();
 
   @After
   public void cleanAll() {

submarine-server/server-submitter/submitter-k8s/src/main/java/org/apache/submarine/server/submitter/k8s/model/xgboostjob/XGBoostJobList.java

@@ -30,7 +30,7 @@ public class XGBoostJobList implements KubernetesListObject {
   private String apiVersion = XGBoostJob.CRD_XGBOOST_API_VERSION_V1;
 
   @SerializedName("kind")
-  private String kind;
+  private String kind = XGBoostJob.CRD_XGBOOST_KIND_V1 + "List";
 
   @SerializedName("metadata")
   private V1ListMeta metadata;
@@ -55,6 +55,6 @@ public String getApiVersion() {
 
   @Override
   public String getKind() {
-    return XGBoostJob.CRD_XGBOOST_KIND_V1 + "List";
+    return kind;
   }
 }