Fix bugs & code smells identified by Sonar

server/src/main/java/org/apache/iotdb/db/exception/sql/MeasurementNotExistException.java

@@ -19,7 +19,7 @@
 
 package org.apache.iotdb.db.exception.sql;
 
-public class MeasurementNotExistException extends SemanticException {
+public class MeasurementNotExistException extends RuntimeException {
 
   public MeasurementNotExistException(String message) {
     super(message);

server/src/main/java/org/apache/iotdb/db/mpp/common/QueryId.java

@@ -33,13 +33,15 @@
 
 public class QueryId {
 
-  public static QueryId mockQueryId = QueryId.valueOf("mock_query_id");
+  public static final QueryId mockQueryId = QueryId.valueOf("mock_query_id");
 
   private final String id;
 
   private int nextPlanNodeIndex;
   private int nextPlanFragmentIndex;
 
+  private static final String INVALID_ID_ERROR_MSG = "Invalid id %s";
+
   public static QueryId valueOf(String queryId) {
     // ID is verified in the constructor
     return new QueryId(queryId);
@@ -94,8 +96,8 @@ public static List<String> parseDottedId(String id, int expectedParts, String na
     checkArgument(ids.size() == expectedParts, "Invalid %s %s", name, id);
 
     for (String part : ids) {
-      checkArgument(!part.isEmpty(), "Invalid id %s", id);
-      checkArgument(isValidId(part), "Invalid id %s", id);
+      checkArgument(!part.isEmpty(), INVALID_ID_ERROR_MSG, id);
+      checkArgument(isValidId(part), INVALID_ID_ERROR_MSG, id);
     }
     return ids;
   }
@@ -128,7 +130,7 @@ private static boolean isValidId(String id) {
   public static String validateId(String id) {
     requireNonNull(id, "id is null");
     checkArgument(!id.isEmpty(), "id is empty");
-    checkArgument(isValidId(id), "Invalid id %s", id);
+    checkArgument(isValidId(id), INVALID_ID_ERROR_MSG, id);
     return id;
   }
 

server/src/main/java/org/apache/iotdb/db/mpp/common/header/ColumnHeaderConstant.java

@@ -27,6 +27,10 @@
 
 public class ColumnHeaderConstant {
 
+  private ColumnHeaderConstant() {
+    // forbidding instantiation
+  }
+
   // column names for query statement
   public static final String TIME = "Time";
   public static final String ENDTIME = "__endTime";

server/src/main/java/org/apache/iotdb/db/mpp/common/header/DatasetHeaderFactory.java

@@ -21,6 +21,10 @@
 
 public class DatasetHeaderFactory {
 
+  private DatasetHeaderFactory() {
+    // forbidding instantiation
+  }
+
   public static DatasetHeader getCountStorageGroupHeader() {
     return new DatasetHeader(ColumnHeaderConstant.countStorageGroupColumnHeaders, true);
   }

server/src/main/java/org/apache/iotdb/db/mpp/common/schematree/ClusterSchemaTree.java

@@ -25,6 +25,7 @@
 import org.apache.iotdb.commons.utils.PathUtils;
 import org.apache.iotdb.commons.utils.TestOnly;
 import org.apache.iotdb.db.exception.metadata.PathNotExistException;
+import org.apache.iotdb.db.exception.sql.SemanticException;
 import org.apache.iotdb.db.mpp.common.schematree.node.SchemaEntityNode;
 import org.apache.iotdb.db.mpp.common.schematree.node.SchemaInternalNode;
 import org.apache.iotdb.db.mpp.common.schematree.node.SchemaMeasurementNode;
@@ -40,7 +41,6 @@
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
-import java.rmi.UnexpectedException;
 import java.util.ArrayDeque;
 import java.util.ArrayList;
 import java.util.Deque;
@@ -184,11 +184,9 @@ public List<Integer> compute(
       if (node == null) {
         indexOfMissingMeasurements.add(index);
       } else {
-        if (firstNonViewMeasurement) {
-          if (!node.getAsMeasurementNode().isLogicalView()) {
-            schemaComputation.computeDevice(cur.getAsEntityNode().isAligned());
-            firstNonViewMeasurement = false;
-          }
+        if (firstNonViewMeasurement && !node.getAsMeasurementNode().isLogicalView()) {
+          schemaComputation.computeDevice(cur.getAsEntityNode().isAligned());
+          firstNonViewMeasurement = false;
         }
         schemaComputation.computeMeasurement(index, node.getAsMeasurementNode());
       }
@@ -214,16 +212,14 @@ public void computeSourceOfLogicalView(
       PartialPath fullPath = logicalViewSchema.getSourcePathIfWritable();
       Pair<List<MeasurementPath>, Integer> searchResult = this.searchMeasurementPaths(fullPath);
       List<MeasurementPath> measurementPathList = searchResult.left;
-      if (measurementPathList.size() <= 0) {
-        throw new RuntimeException(
+      if (measurementPathList.isEmpty()) {
+        throw new SemanticException(
             new PathNotExistException(
                 String.format(
                     "The source path of view [%s] does not exist.", fullPath.getFullPath())));
       } else if (measurementPathList.size() > 1) {
-        throw new RuntimeException(
-            new UnexpectedException(
-                String.format(
-                    "The source paths of view [%s] are multiple.", fullPath.getFullPath())));
+        throw new SemanticException(
+            String.format("The source paths of view [%s] are multiple.", fullPath.getFullPath()));
       } else {
         Integer realIndex = schemaComputation.getIndexListOfLogicalViewPaths().get(index);
         MeasurementPath measurementPath = measurementPathList.get(0);
@@ -407,7 +403,7 @@ public String getBelongedDatabase(String pathName) {
         return database;
       }
     }
-    throw new RuntimeException("No matched database. Please check the path " + pathName);
+    throw new SemanticException("No matched database. Please check the path " + pathName);
   }
 
   @Override

server/src/main/java/org/apache/iotdb/db/mpp/common/schematree/visitor/SchemaTreeVisitor.java

@@ -31,7 +31,7 @@ public abstract class SchemaTreeVisitor<R> extends AbstractTreeVisitor<SchemaNod
 
   protected SchemaTreeVisitor() {}
 
-  public SchemaTreeVisitor(SchemaNode root, PartialPath pathPattern, boolean isPrefixMatch) {
+  protected SchemaTreeVisitor(SchemaNode root, PartialPath pathPattern, boolean isPrefixMatch) {
     super(root, pathPattern, isPrefixMatch);
     initStack();
   }

server/src/main/java/org/apache/iotdb/db/mpp/common/schematree/visitor/SchemaTreeVisitorFactory.java

@@ -23,6 +23,11 @@
 import org.apache.iotdb.db.mpp.common.schematree.node.SchemaNode;
 
 public class SchemaTreeVisitorFactory {
+
+  private SchemaTreeVisitorFactory() {
+    // forbidden instantiation
+  }
+
   public static SchemaTreeDeviceVisitor createSchemaTreeDeviceVisitor(
       SchemaNode root, PartialPath pathPattern, boolean isPrefixMatch) {
     return new SchemaTreeDeviceVisitor(root, pathPattern, isPrefixMatch);

server/src/main/java/org/apache/iotdb/db/mpp/plan/Coordinator.java

@@ -16,6 +16,7 @@
  * specific language governing permissions and limitations
  * under the License.
  */
+
 package org.apache.iotdb.db.mpp.plan;
 
 import org.apache.iotdb.common.rpc.thrift.TEndPoint;

server/src/main/java/org/apache/iotdb/db/mpp/plan/analyze/Analysis.java

@@ -66,9 +66,6 @@ public class Analysis {
   // Statement
   private Statement statement;
 
-  // indicate whether this statement is `WRITE` or `READ`
-  private QueryType queryType;
-
   private DataPartition dataPartition;
 
   private SchemaPartition schemaPartition;
@@ -111,15 +108,17 @@ public class Analysis {
   // tag keys specified in `GROUP BY TAG` clause
   private List<String> tagKeys;
 
-  // {tag values -> {grouped expression -> output expressions}}
-  // For different combination of tag keys, the grouped expression may be different. Let's say there
-  // are 3 timeseries root.sg.d1.temperature, root.sg.d1.status, root.sg.d2.temperature, and their
-  // tags are [k1=v1], [k1=v1] and [k1=v2] respectively. For query "SELECT last_value(**) FROM root
-  // GROUP BY k1", timeseries are grouped by their tags into 2 buckets. Bucket [v1] has
-  // [root.sg.d1.temperature, root.sg.d1.status], while bucket [v2] has [root.sg.d2.temperature].
-  // Thus, the aggregation results of bucket [v1] and [v2] are different. Bucket [v1] has 2
-  // aggregation results last_value(temperature) and last_value(status), whereas bucket [v2] only
-  // has [last_value(temperature)].
+  /*
+  tag values -> (grouped expression -> output expressions)
+  For different combination of tag keys, the grouped expression may be different. Let's say there
+   are 3 timeseries root.sg.d1.temperature, root.sg.d1.status, root.sg.d2.temperature, and their
+   tags are [k1=v1], [k1=v1] and [k1=v2] respectively. For query "SELECT last_value(**) FROM root
+   GROUP BY k1", timeseries are grouped by their tags into 2 buckets. Bucket [v1] has
+   [root.sg.d1.temperature, root.sg.d1.status], while bucket [v2] has [root.sg.d2.temperature].
+   Thus, the aggregation results of bucket [v1] and [v2] are different. Bucket [v1] has 2
+   aggregation results last_value(temperature) and last_value(status), whereas bucket [v2] only
+  has [last_value(temperature)].
+   */
   private Map<List<String>, LinkedHashMap<Expression, List<Expression>>>
       tagValuesToGroupedTimeseriesOperands;
 
@@ -260,6 +259,7 @@ public List<TRegionReplicaSet> getPartitionInfo(PartialPath seriesPath, Filter t
   }
 
   public List<TRegionReplicaSet> getPartitionInfo(String deviceName, Filter globalTimeFilter) {
+    // TODO: (xingtanzjr) implement the calculation of timePartitionIdList
     return dataPartition.getDataRegionReplicaSet(deviceName, null);
   }