[CALCITE-6552] Enable CheckerFramework in 'server' module

.github/workflows/main.yml

@@ -377,9 +377,9 @@ jobs:
         with:
           job-id: checkerframework-jdk11
           remote-build-cache-proxy-enabled: false
-          arguments: --scan --no-parallel --no-daemon -PenableCheckerframework :linq4j:classes :core:classes
+          arguments: --scan --no-parallel --no-daemon -PenableCheckerframework :linq4j:classes :core:classes :server:classes
 
-  linux-checkerframework-guava29:
+  linux-checkerframework-oldest-guava:
     name: 'CheckerFramework (JDK 11), oldest Guava'
     runs-on: ubuntu-latest
     env:
@@ -398,7 +398,7 @@ jobs:
         with:
           job-id: checkerframework-jdk11
           remote-build-cache-proxy-enabled: false
-          arguments: --scan --no-parallel --no-daemon -Pguava.version=${{ env.GUAVA }} -PenableCheckerframework :linq4j:classes :core:classes
+          arguments: --scan --no-parallel --no-daemon -Pguava.version=${{ env.GUAVA }} -PenableCheckerframework :linq4j:classes :core:classes :server:classes
 
   linux-slow:
     # Run slow tests when the commit is on main or it is requested explicitly by adding an

arrow/src/main/java/org/apache/calcite/adapter/arrow/ArrowFilterEnumerator.java

@@ -29,16 +29,20 @@
 import org.apache.arrow.vector.ipc.ArrowFileReader;
 import org.apache.arrow.vector.ipc.message.ArrowRecordBatch;
 
+import org.checkerframework.checker.nullness.qual.Nullable;
+
 import java.io.IOException;
 
+import static java.util.Objects.requireNonNull;
+
 /**
  * Enumerator that reads from a filtered collection of Arrow value-vectors.
  */
 class ArrowFilterEnumerator extends AbstractArrowEnumerator {
   private final BufferAllocator allocator;
   private final Filter filter;
-  private ArrowBuf buf;
-  private SelectionVector selectionVector;
+  private @Nullable ArrowBuf buf;
+  private @Nullable SelectionVector selectionVector;
   private int selectionVectorIndex;
 
   ArrowFilterEnumerator(ArrowFileReader arrowFileReader, ImmutableIntList fields, Filter filter) {
@@ -71,7 +75,7 @@ class ArrowFilterEnumerator extends AbstractArrowEnumerator {
           selectionVectorIndex = 0;
           this.valueVectors.clear();
           loadNextArrowBatch();
-          assert selectionVector != null;
+          requireNonNull(selectionVector, "selectionVector");
           if (selectionVectorIndex >= selectionVector.getRecordCount()) {
             // the "filtered" batch is empty, but there may be more batches to fetch
             continue;

arrow/src/main/java/org/apache/calcite/adapter/arrow/ArrowTable.java

@@ -55,6 +55,10 @@
 import java.util.ArrayList;
 import java.util.List;
 
+import static java.lang.Double.parseDouble;
+import static java.lang.Float.parseFloat;
+import static java.lang.Integer.parseInt;
+import static java.lang.Long.parseLong;
 import static java.util.Objects.requireNonNull;
 
 /**
@@ -183,13 +187,13 @@ private static RelDataType deduceRowType(Schema schema,
   private static TreeNode makeLiteralNode(String literal, String type) {
     switch (type) {
     case "integer":
-      return TreeBuilder.makeLiteral(Integer.parseInt(literal));
+      return TreeBuilder.makeLiteral(parseInt(literal));
     case "long":
-      return TreeBuilder.makeLiteral(Long.parseLong(literal));
+      return TreeBuilder.makeLiteral(parseLong(literal));
     case "float":
-      return TreeBuilder.makeLiteral(Float.parseFloat(literal));
+      return TreeBuilder.makeLiteral(parseFloat(literal));
     case "double":
-      return TreeBuilder.makeLiteral(Double.parseDouble(literal));
+      return TreeBuilder.makeLiteral(parseDouble(literal));
     case "string":
       return TreeBuilder.makeStringLiteral(literal.substring(1, literal.length() - 1));
     default:

arrow/src/test/java/org/apache/calcite/adapter/arrow/ArrowAdapterTest.java

@@ -43,10 +43,11 @@
 import java.nio.file.Path;
 import java.sql.SQLException;
 import java.util.Map;
-import java.util.Objects;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
+import static java.util.Objects.requireNonNull;
+
 /**
  * Tests for the Apache Arrow adapter.
  */
@@ -57,9 +58,11 @@ class ArrowAdapterTest {
   private static File arrowDataDirectory;
 
   @BeforeAll
-  static void initializeArrowState(@TempDir Path sharedTempDir) throws IOException, SQLException {
+  static void initializeArrowState(@TempDir Path sharedTempDir)
+      throws IOException, SQLException {
     URL modelUrl =
-        Objects.requireNonNull(ArrowAdapterTest.class.getResource("/arrow-model.json"), "url");
+        requireNonNull(
+            ArrowAdapterTest.class.getResource("/arrow-model.json"), "url");
     Path sourceModelFilePath = Sources.of(modelUrl).file().toPath();
     Path modelFileTarget = sharedTempDir.resolve("arrow-model.json");
     Files.copy(sourceModelFilePath, modelFileTarget);

build.gradle.kts

@@ -666,6 +666,14 @@ allprojects {
                     replace("hamcrest: sameInstance", "org.hamcrest.core.IsSame.sameInstance", "org.hamcrest.CoreMatchers.sameInstance")
                     replace("hamcrest: startsWith", "org.hamcrest.core.StringStartsWith.startsWith", "org.hamcrest.CoreMatchers.startsWith")
                     replaceRegex("hamcrest: size", "\\.size\\(\\), (is|equalTo)\\(", ", hasSize\\(")
+                    replaceRegex("use static import: parseBoolean", "Boolean\\.(parseBoolean\\()", "$1")
+                    replaceRegex("use static import: parseByte", "Byte\\.(parseByte\\()", "$1")
+                    replaceRegex("use static import: parseDouble", "Double\\.(parseDouble\\()", "$1")
+                    replaceRegex("use static import: parseFloat", "Float\\.(parseFloat\\()", "$1")
+                    replaceRegex("use static import: parseInt", "Integer\\.(parseInt\\()", "$1")
+                    replaceRegex("use static import: parseLong", "Long\\.(parseLong\\()", "$1")
+                    replaceRegex("use static import: parseLong", "Short\\.(parseShort\\()", "$1")
+                    replaceRegex("use static import: requireNonNull", "Objects\\.(requireNonNull\\()", "$1")
                     replaceRegex("use static import: toImmutableList", "ImmutableList\\.(toImmutableList\\(\\))", "$1")
                     replaceRegex("use static import: checkArgument", "Preconditions\\.(checkArgument\\()", "$1")
                     replaceRegex("use static import: checkArgument", "Preconditions\\.(checkState\\()", "$1")
@@ -778,6 +786,9 @@ allprojects {
                 if (project.path == ":core") {
                     extraJavacArgs.add("-AskipDefs=^org\\.apache\\.calcite\\.sql\\.parser\\.impl\\.")
                 }
+                if (project.path == ":server") {
+                    extraJavacArgs.add("-AskipDefs=^org\\.apache\\.calcite\\.sql\\.parser\\.ddl\\.")
+                }
             }
         }
 

cassandra/src/main/java/org/apache/calcite/adapter/cassandra/CassandraEnumerator.java

@@ -42,6 +42,8 @@
 import java.util.Objects;
 import java.util.stream.IntStream;
 
+import static java.util.Objects.requireNonNull;
+
 /** Enumerator that reads from a Cassandra column family. */
 class CassandraEnumerator implements Enumerator<Object> {
   private final Iterator<Row> iterator;
@@ -86,7 +88,7 @@ class CassandraEnumerator implements Enumerator<Object> {
    * @param index Index of the field within the Row object
    */
   private @Nullable Object currentRowField(int index) {
-    assert current != null;
+    requireNonNull(current, "current");
     final Object o =
          current.get(index,
              CodecRegistry.DEFAULT.codecFor(

cassandra/src/main/java/org/apache/calcite/adapter/cassandra/CassandraFilter.java

@@ -46,12 +46,13 @@
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
-import java.util.Objects;
 import java.util.Set;
 
 import static org.apache.calcite.util.DateTimeStringUtils.ISO_DATETIME_FRACTIONAL_SECOND_FORMAT;
 import static org.apache.calcite.util.DateTimeStringUtils.getDateFormatter;
 
+import static java.util.Objects.requireNonNull;
+
 /**
  * Implementation of a {@link org.apache.calcite.rel.core.Filter}
  * relational expression in Cassandra.
@@ -297,7 +298,7 @@ private String translateOp2(String op, String name, RexLiteral right) {
       String valueString = value.toString();
       if (value instanceof String) {
         RelDataTypeField field =
-            Objects.requireNonNull(rowType.getField(name, true, false));
+            requireNonNull(rowType.getField(name, true, false));
         SqlTypeName typeName = field.getType().getSqlTypeName();
         if (typeName != SqlTypeName.CHAR) {
           valueString = "'" + valueString + "'";

cassandra/src/main/java/org/apache/calcite/adapter/cassandra/CassandraProject.java

@@ -36,6 +36,8 @@
 import java.util.List;
 import java.util.Map;
 
+import static java.util.Objects.requireNonNull;
+
 /**
  * Implementation of {@link org.apache.calcite.rel.core.Project}
  * relational expression in Cassandra.
@@ -56,7 +58,8 @@ public CassandraProject(RelOptCluster cluster, RelTraitSet traitSet,
 
   @Override public @Nullable RelOptCost computeSelfCost(RelOptPlanner planner,
       RelMetadataQuery mq) {
-    return super.computeSelfCost(planner, mq).multiplyBy(0.1);
+    final RelOptCost cost = super.computeSelfCost(planner, mq);
+    return requireNonNull(cost, "cost").multiplyBy(0.1);
   }
 
   @Override public void implement(Implementor implementor) {
@@ -66,9 +69,9 @@ public CassandraProject(RelOptCluster cluster, RelTraitSet traitSet,
             CassandraRules.cassandraFieldNames(getInput().getRowType()));
     final Map<String, String> fields = new LinkedHashMap<>();
     for (Pair<RexNode, String> pair : getNamedProjects()) {
-      assert pair.left != null;
+      final RexNode node = pair.left;
       final String name = pair.right;
-      final String originalName = pair.left.accept(translator);
+      final String originalName = node.accept(translator);
       fields.put(originalName, name);
     }
     implementor.add(fields, null);

cassandra/src/main/java/org/apache/calcite/adapter/cassandra/CassandraSchema.java

@@ -62,11 +62,12 @@
 import java.util.Collection;
 import java.util.List;
 import java.util.Map;
-import java.util.Objects;
 import java.util.Optional;
 import java.util.stream.Collectors;
 import java.util.stream.IntStream;
 
+import static java.util.Objects.requireNonNull;
+
 /**
  * Schema mapped onto a Cassandra column family.
  */
@@ -297,7 +298,7 @@ private void addMaterializedViews() {
           + "WHERE keyspace_name='" + keyspace + "' AND view_name='"
           + view.getName().asInternal() + "'";
 
-      Row whereClauseRow = Objects.requireNonNull(session.execute(whereQuery).one());
+      Row whereClauseRow = requireNonNull(session.execute(whereQuery).one());
 
       queryBuilder.append(" WHERE ")
           .append(whereClauseRow.getString(0));

cassandra/src/main/java/org/apache/calcite/adapter/cassandra/CassandraSchemaFactory.java

@@ -34,6 +34,8 @@
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.stream.Collectors;
 
+import static java.lang.Integer.parseInt;
+
 /**
  * Factory that creates a {@link CassandraSchema}.
  */
@@ -107,7 +109,7 @@ private static int getPort(Map<String, Object> map) {
     if (map.containsKey("port")) {
       Object portObj = map.get("port");
       if (portObj instanceof String) {
-        return Integer.parseInt((String) portObj);
+        return parseInt((String) portObj);
       } else {
         return (int) portObj;
       }

cassandra/src/main/java/org/apache/calcite/adapter/cassandra/CassandraToEnumerableConverter.java

@@ -46,7 +46,8 @@
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
-import java.util.Objects;
+
+import static java.util.Objects.requireNonNull;
 
 /**
  * Relational expression representing a scan of a table in a Cassandra data source.
@@ -105,7 +106,7 @@ protected CassandraToEnumerableConverter(
         list.append("selectFields", constantArrayList(selectList, Pair.class));
     final Expression table =
         list.append("table",
-            Objects.requireNonNull(
+            requireNonNull(
                 cassandraImplementor.table.getExpression(
                     CassandraTable.CassandraQueryable.class)));
     final Expression predicates =

cassandra/src/test/java/org/apache/calcite/test/CassandraExtension.java

@@ -41,11 +41,13 @@
 import java.io.IOException;
 import java.io.UncheckedIOException;
 import java.lang.reflect.Field;
+import java.net.URL;
 import java.time.Duration;
 import java.util.Locale;
-import java.util.Objects;
 import java.util.concurrent.ExecutionException;
 
+import static java.util.Objects.requireNonNull;
+
 /**
  * JUnit5 extension to start and stop embedded Cassandra server.
  *
@@ -83,9 +85,9 @@ class CassandraExtension implements ParameterResolver, ExecutionCondition {
   }
 
   static ImmutableMap<String, String> getDataset(String resourcePath) {
+    URL u = CassandraExtension.class.getResource(resourcePath);
     return ImmutableMap.of("model",
-        Sources.of(Objects.requireNonNull(CassandraExtension.class.getResource(resourcePath)))
-            .file().getAbsolutePath());
+        Sources.of(requireNonNull(u, "u")).file().getAbsolutePath());
   }
 
   /** Registers a Cassandra resource in root context, so it can be shared with

core/src/main/codegen/templates/Parser.jj

@@ -1745,10 +1745,10 @@ SqlNode SqlInsert() :
     (
         LOOKAHEAD(2)
         p = ParenthesizedCompoundIdentifierList() {
-            if (p.right.size() > 0) {
+            if (!p.right.isEmpty()) {
                 tableRef = extend(tableRef, p.right);
             }
-            if (p.left.size() > 0) {
+            if (!p.left.isEmpty()) {
                 columnList = p.left;
             } else {
                 columnList = null;

core/src/main/java/org/apache/calcite/adapter/enumerable/EnumUtils.java

@@ -356,15 +356,15 @@ static List<Expression> fromInternal(Class<?>[] targetTypes,
       }
     } else {
       int j = 0;
-      for (int i = 0; i < expressions.size(); i++) {
+      for (Expression expression : expressions) {
         Class<?> type;
         if (!targetTypes[j].isArray()) {
           type = targetTypes[j];
           j++;
         } else {
           type = targetTypes[j].getComponentType();
         }
-        list.add(fromInternal(expressions.get(i), type));
+        list.add(fromInternal(expression, type));
       }
     }
     return list;
@@ -453,7 +453,7 @@ public static Expression convert(Expression operand, Type fromType,
               "to" + SqlFunctions.initcap(toPrimitive.getPrimitiveName()),
               operand);
         default:
-          // Generate "Short.parseShort(x)".
+          // Generate "parseShort(x)".
           return Expressions.call(
               toPrimitive.getBoxClass(),
               "parse" + SqlFunctions.initcap(toPrimitive.getPrimitiveName()),
@@ -993,7 +993,7 @@ private static class SessionizationEnumerator implements Enumerator<@Nullable Ob
     }
 
     @Override public boolean moveNext() {
-      return initialized ? list.size() > 0 : inputEnumerator.moveNext();
+      return initialized ? !list.isEmpty() : inputEnumerator.moveNext();
     }
 
     @Override public void reset() {
@@ -1133,7 +1133,7 @@ private static class HopEnumerator implements Enumerator<@Nullable Object[]> {
     }
 
     @Override public @Nullable Object[] current() {
-      if (list.size() > 0) {
+      if (!list.isEmpty()) {
         return takeOne();
       } else {
         @Nullable Object[] current = inputEnumerator.current();
@@ -1155,7 +1155,7 @@ private static class HopEnumerator implements Enumerator<@Nullable Object[]> {
     }
 
     @Override public boolean moveNext() {
-      return list.size() > 0 || inputEnumerator.moveNext();
+      return !list.isEmpty() || inputEnumerator.moveNext();
     }
 
     @Override public void reset() {

core/src/main/java/org/apache/calcite/adapter/enumerable/EnumerableAsofJoin.java

@@ -128,14 +128,14 @@ public static EnumerableAsofJoin create(
     return planner.getCostFactory().makeCost(rowCount, 0, 0);
   }
 
-  /** Generate the function that compares two rows from the right collection on their
-   * timestamp field.
+  /** Generates the function that compares two rows from the right collection on
+   * their timestamp field.
    *
    * @param rightCollectionType  Type of data in right collection.
    * @param kind                 Comparison kind.
    * @param timestampFieldIndex  Index of the field that is the timestamp field.
    */
-  private Expression generateTimestampComparator(
+  private static Expression generateTimestampComparator(
       PhysType rightCollectionType, SqlKind kind, int timestampFieldIndex) {
     RelFieldCollation.Direction direction;
     switch (kind) {
@@ -159,7 +159,7 @@ private Expression generateTimestampComparator(
     return rightCollectionType.generateComparator(collation);
   }
 
-  /** Extract from a comparison 'call' the index of the field from
+  /** Extracts from a comparison 'call' the index of the field from
    * the inner collection that is used in the comparison. */
   private int getTimestampFieldIndex(RexCall call) {
     int timestampFieldIndex;