GH-44055: [Java] Finalize ErrorProne Warnings to be considered as Errors

java/adapter/avro/pom.xml

@@ -57,17 +57,4 @@ under the License.
     </dependency>
   </dependencies>
 
-  <build>
-    <plugins>
-      <plugin>
-        <groupId>org.apache.maven.plugins</groupId>
-        <artifactId>maven-compiler-plugin</artifactId>
-        <configuration combine.children="append">
-          <compilerArgs>
-            <arg>-Werror</arg>
-          </compilerArgs>
-        </configuration>
-      </plugin>
-    </plugins>
-  </build>
 </project>

java/adapter/jdbc/pom.xml

@@ -84,6 +84,13 @@ under the License.
       <artifactId>jackson-annotations</artifactId>
     </dependency>
 
+    <dependency>
+      <groupId>org.apache.commons</groupId>
+      <artifactId>commons-lang3</artifactId>
+      <version>${commons.lang3.version}</version>
+      <scope>test</scope>
+    </dependency>
+
     <dependency>
       <groupId>org.assertj</groupId>
       <artifactId>assertj-core</artifactId>
@@ -116,15 +123,6 @@ under the License.
           <argLine>--add-reads=org.apache.arrow.adapter.jdbc=com.fasterxml.jackson.dataformat.yaml --add-opens=java.base/java.nio=org.apache.arrow.memory.core,ALL-UNNAMED -Duser.timezone=UTC</argLine>
         </configuration>
       </plugin>
-      <plugin>
-        <groupId>org.apache.maven.plugins</groupId>
-        <artifactId>maven-compiler-plugin</artifactId>
-        <configuration combine.children="append">
-          <compilerArgs>
-            <arg>-Werror</arg>
-          </compilerArgs>
-        </configuration>
-      </plugin>
     </plugins>
   </build>
 </project>

java/adapter/jdbc/src/test/java/org/apache/arrow/adapter/jdbc/JdbcToArrowTestHelper.java

@@ -58,6 +58,7 @@
 import org.apache.arrow.vector.util.JsonStringHashMap;
 import org.apache.arrow.vector.util.ObjectMapperFactory;
 import org.apache.arrow.vector.util.Text;
+import org.apache.commons.lang3.StringUtils;
 
 /**
  * This is a Helper class which has functionalities to read and assert the values from the given
@@ -447,24 +448,22 @@ public static byte[][] getBinaryValues(String[] values, String dataType) {
     return valueArr;
   }
 
-  @SuppressWarnings("StringSplitter")
   public static String[] getValues(String[] values, String dataType) {
     String value = "";
     for (String val : values) {
       if (val.startsWith(dataType)) {
-        value = val.split("=")[1];
+        value = StringUtils.split(val, "=")[1];
         break;
       }
     }
-    return value.split(",");
+    return StringUtils.split(value, ",");
   }
 
   public static Integer[][] getListValues(String[] values, String dataType) {
     String[] dataArr = getValues(values, dataType);
     return getListValues(dataArr);
   }
 
-  @SuppressWarnings("StringSplitter")
   public static Integer[][] getListValues(String[] dataArr) {
     Integer[][] valueArr = new Integer[dataArr.length][];
     int i = 0;
@@ -474,7 +473,7 @@ public static Integer[][] getListValues(String[] dataArr) {
       } else if ("()".equals(data.trim())) {
         valueArr[i++] = new Integer[0];
       } else {
-        String[] row = data.replace("(", "").replace(")", "").split(";");
+        String[] row = StringUtils.split(data.replace("(", "").replace(")", ""), ";");
         Integer[] arr = new Integer[row.length];
         for (int j = 0; j < arr.length; j++) {
           arr[j] = "null".equals(row[j]) ? null : Integer.parseInt(row[j]);

java/adapter/jdbc/src/test/java/org/apache/arrow/adapter/jdbc/h2/JdbcToArrowVectorIteratorTest.java

@@ -27,10 +27,10 @@
 import static org.apache.arrow.adapter.jdbc.JdbcToArrowTestHelper.getLongValues;
 import static org.junit.jupiter.api.Assertions.assertArrayEquals;
 import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertNotEquals;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertSame;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import java.io.IOException;
@@ -146,10 +146,10 @@ public void testVectorSchemaRootReuse(Table table, boolean reuseVectorSchemaRoot
 
         if (reuseVectorSchemaRoot) {
           // when reuse is enabled, different iterations are based on the same vector schema root.
-          assertTrue(prev == cur);
+          assertSame(prev, cur);
         } else {
           // when reuse is enabled, a new vector schema root is created in each iteration.
-          assertFalse(prev == cur);
+          assertNotEquals(prev, cur);
           if (batchCount < 3) {
             cur.close();
           }

java/adapter/orc/pom.xml

@@ -160,15 +160,6 @@ under the License.
           </execution>
         </executions>
       </plugin>
-      <plugin>
-        <groupId>org.apache.maven.plugins</groupId>
-        <artifactId>maven-compiler-plugin</artifactId>
-        <configuration combine.children="append">
-          <compilerArgs>
-            <arg>-Werror</arg>
-          </compilerArgs>
-        </configuration>
-      </plugin>
     </plugins>
   </build>
 </project>

java/c/pom.xml

@@ -91,16 +91,5 @@ under the License.
         </includes>
       </resource>
     </resources>
-    <plugins>
-      <plugin>
-        <groupId>org.apache.maven.plugins</groupId>
-        <artifactId>maven-compiler-plugin</artifactId>
-        <configuration combine.children="append">
-          <compilerArgs>
-            <arg>-Werror</arg>
-          </compilerArgs>
-        </configuration>
-      </plugin>
-    </plugins>
   </build>
 </project>

java/c/src/test/java/org/apache/arrow/c/RoundtripTest.java

@@ -16,6 +16,7 @@
  */
 package org.apache.arrow.c;
 
+import static org.apache.arrow.vector.complex.BaseRepeatedValueVector.DATA_VECTOR_NAME;
 import static org.apache.arrow.vector.testing.ValueVectorDataPopulator.setVector;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertThrows;
@@ -965,7 +966,9 @@ public void testImportReleasedArray() {
       try (ArrowSchema arrowSchema = ArrowSchema.wrap(consumerArrowSchema.memoryAddress());
           ArrowArray arrowArray = ArrowArray.wrap(consumerArrowArray.memoryAddress())) {
         // Producer exports vector into the C Data Interface structures
-        try (final NullVector vector = new NullVector()) {
+        try (final NullVector vector =
+            new NullVector(
+                new Field(DATA_VECTOR_NAME, FieldType.nullable(new ArrowType.Null()), null))) {
           Data.exportVector(allocator, vector, null, arrowArray, arrowSchema);
         }
       }

java/dataset/pom.xml

@@ -202,15 +202,6 @@ under the License.
           </execution>
         </executions>
       </plugin>
-      <plugin>
-        <groupId>org.apache.maven.plugins</groupId>
-        <artifactId>maven-compiler-plugin</artifactId>
-        <configuration combine.children="append">
-          <compilerArgs>
-            <arg>-Werror</arg>
-          </compilerArgs>
-        </configuration>
-      </plugin>
     </plugins>
   </build>
 </project>

java/flight/flight-core/src/main/java/org/apache/arrow/flight/CloseSessionResult.java

@@ -41,6 +41,7 @@ public static Status fromProtocol(Flight.CloseSessionResult.Status proto) {
       return values()[proto.getNumber()];
     }
 
+    @SuppressWarnings("EnumOrdinal")
     public Flight.CloseSessionResult.Status toProtocol() {
       return Flight.CloseSessionResult.Status.values()[ordinal()];
     }

java/flight/flight-core/src/main/java/org/apache/arrow/flight/DictionaryUtils.java

@@ -79,7 +79,7 @@ static Schema generateSchemaMessages(
               count);
       final VectorUnloader unloader = new VectorUnloader(dictRoot);
       try (final ArrowDictionaryBatch dictionaryBatch =
-              new ArrowDictionaryBatch(id, unloader.getRecordBatch());
+              new ArrowDictionaryBatch(id, unloader.getRecordBatch(), false);
           final ArrowMessage message = new ArrowMessage(dictionaryBatch, option)) {
         messageCallback.accept(message);
       }

java/flight/flight-core/src/main/java/org/apache/arrow/flight/FlightRuntimeException.java

@@ -37,6 +37,11 @@ public CallStatus status() {
 
   @Override
   public String toString() {
+    return getMessage();
+  }
+
+  @Override
+  public String getMessage() {
     String s = getClass().getName();
     return String.format("%s: %s: %s", s, status.code(), status.description());
   }

java/flight/flight-core/src/main/java/org/apache/arrow/flight/NoOpSessionOptionValueVisitor.java

@@ -25,26 +25,31 @@
  */
 public class NoOpSessionOptionValueVisitor<T> implements SessionOptionValueVisitor<T> {
   /** A callback to handle SessionOptionValue containing a String. */
+  @Override
   public T visit(String value) {
     return null;
   }
 
   /** A callback to handle SessionOptionValue containing a boolean. */
+  @Override
   public T visit(boolean value) {
     return null;
   }
 
   /** A callback to handle SessionOptionValue containing a long. */
+  @Override
   public T visit(long value) {
     return null;
   }
 
   /** A callback to handle SessionOptionValue containing a double. */
+  @Override
   public T visit(double value) {
     return null;
   }
 
   /** A callback to handle SessionOptionValue containing an array of String. */
+  @Override
   public T visit(String[] value) {
     return null;
   }
@@ -55,6 +60,7 @@ public T visit(String[] value) {
    * <p>By convention, an attempt to set a valueless SessionOptionValue should attempt to unset or
    * clear the named option value on the server.
    */
+  @Override
   public T visit(Void value) {
     return null;
   }

java/flight/flight-core/src/main/java/org/apache/arrow/flight/ServerSessionMiddleware.java

@@ -75,6 +75,7 @@ private void closeSession(String id) {
     }
 
     @Override
+    @SuppressWarnings("StringSplitter")
     public ServerSessionMiddleware onCallStarted(
         CallInfo callInfo, CallHeaders incomingHeaders, RequestContext context) {
       String sessionId = null;
@@ -90,7 +91,7 @@ public ServerSessionMiddleware onCallStarted(
               break;
             }
 
-            if (sessionCookieName.equals(cookiePair[0]) && cookiePair[1].length() > 0) {
+            if (sessionCookieName.equals(cookiePair[0]) && !cookiePair[1].isEmpty()) {
               sessionId = cookiePair[1];
               break findIdCookie;
             }

java/flight/flight-core/src/main/java/org/apache/arrow/flight/SessionOptionValue.java

@@ -38,7 +38,8 @@ public boolean isEmpty() {
     return false;
   }
 
-  private class SessionOptionValueToProtocolVisitor implements SessionOptionValueVisitor<Void> {
+  private static class SessionOptionValueToProtocolVisitor
+      implements SessionOptionValueVisitor<Void> {
     final Flight.SessionOptionValue.Builder b;
 
     SessionOptionValueToProtocolVisitor(Flight.SessionOptionValue.Builder b) {

java/flight/flight-core/src/main/java/org/apache/arrow/flight/SessionOptionValueFactory.java

@@ -89,7 +89,7 @@ public boolean equals(Object o) {
       if (this == o) {
         return true;
       }
-      if (o == null || getClass() != o.getClass()) {
+      if (!(o instanceof SessionOptionValueString)) {
         return false;
       }
       SessionOptionValueString that = (SessionOptionValueString) o;
@@ -124,7 +124,7 @@ public boolean equals(Object o) {
       if (this == o) {
         return true;
       }
-      if (o == null || getClass() != o.getClass()) {
+      if (!(o instanceof SessionOptionValueBoolean)) {
         return false;
       }
       SessionOptionValueBoolean that = (SessionOptionValueBoolean) o;
@@ -159,7 +159,7 @@ public boolean equals(Object o) {
       if (this == o) {
         return true;
       }
-      if (o == null || getClass() != o.getClass()) {
+      if (!(o instanceof SessionOptionValueLong)) {
         return false;
       }
       SessionOptionValueLong that = (SessionOptionValueLong) o;
@@ -194,7 +194,7 @@ public boolean equals(Object o) {
       if (this == o) {
         return true;
       }
-      if (o == null || getClass() != o.getClass()) {
+      if (!(o instanceof SessionOptionValueDouble)) {
         return false;
       }
       SessionOptionValueDouble that = (SessionOptionValueDouble) o;
@@ -229,7 +229,7 @@ public boolean equals(Object o) {
       if (this == o) {
         return true;
       }
-      if (o == null || getClass() != o.getClass()) {
+      if (!(o instanceof SessionOptionValueStringList)) {
         return false;
       }
       SessionOptionValueStringList that = (SessionOptionValueStringList) o;
@@ -266,7 +266,7 @@ public boolean equals(Object o) {
       if (this == o) {
         return true;
       }
-      if (o == null || getClass() != o.getClass()) {
+      if (!(o instanceof SessionOptionValueEmpty)) {
         return false;
       }
       return true;

java/flight/flight-core/src/main/java/org/apache/arrow/flight/SetSessionOptionsResult.java

@@ -45,12 +45,14 @@ static ErrorValue fromProtocol(Flight.SetSessionOptionsResult.ErrorValue s) {
       return values()[s.getNumber()];
     }
 
+    @SuppressWarnings("EnumOrdinal")
     Flight.SetSessionOptionsResult.ErrorValue toProtocol() {
       return Flight.SetSessionOptionsResult.ErrorValue.values()[ordinal()];
     }
   }
 
   /** Per-option extensible error response container. */
+  @SuppressWarnings("JavaLangClash")
   public static class Error {
     public ErrorValue value;
 
@@ -74,7 +76,7 @@ public boolean equals(Object o) {
       if (this == o) {
         return true;
       }
-      if (o == null || getClass() != o.getClass()) {
+      if (!(o instanceof Error)) {
         return false;
       }
       Error that = (Error) o;

java/flight/flight-core/src/main/java/org/apache/arrow/flight/grpc/AddWritableBuffer.java

@@ -70,8 +70,8 @@ public class AddWritableBuffer {
       tmpBufChainOut = tmpBufChainOut2;
 
     } catch (Exception ex) {
-      new RuntimeException("Failed to initialize AddWritableBuffer, falling back to slow path", ex)
-          .printStackTrace();
+      throw new RuntimeException(
+          "Failed to initialize AddWritableBuffer, falling back to slow path", ex);
     }
 
     bufConstruct = tmpConstruct;

java/flight/flight-core/src/main/java/org/apache/arrow/flight/grpc/GetReadableBuffer.java

@@ -47,8 +47,8 @@ public class GetReadableBuffer {
       tmpField = f;
       tmpClazz = clazz;
     } catch (Exception e) {
-      new RuntimeException("Failed to initialize GetReadableBuffer, falling back to slow path", e)
-          .printStackTrace();
+      throw new RuntimeException(
+          "Failed to initialize GetReadableBuffer, falling back to slow path", e);
     }
     READABLE_BUFFER = tmpField;
     BUFFER_INPUT_STREAM = tmpClazz;