GH-759: Get length of byte[] in TryCopyLastError

c/src/main/cpp/jni_wrapper.cc

@@ -205,8 +205,9 @@ void TryCopyLastError(JNIEnv* env, InnerPrivateData* private_data) {
     return;
   }
 
+  jsize error_bytes_len = env->GetArrayLength(arr);
   char* error_str = reinterpret_cast<char*>(error_bytes);
-  private_data->last_error_ = std::string(error_str, std::strlen(error_str));
+  private_data->last_error_ = std::string(error_str, error_bytes_len);
 
   env->ReleaseByteArrayElements(arr, error_bytes, JNI_ABORT);
 }

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

@@ -0,0 +1,157 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.arrow.c;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.catchThrowableOfType;
+
+import java.io.IOException;
+import java.io.PrintWriter;
+import java.io.StringWriter;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.Objects;
+import java.util.function.Function;
+import java.util.stream.Collectors;
+import org.apache.arrow.c.jni.CDataJniException;
+import org.apache.arrow.memory.BufferAllocator;
+import org.apache.arrow.memory.RootAllocator;
+import org.apache.arrow.vector.IntVector;
+import org.apache.arrow.vector.VectorLoader;
+import org.apache.arrow.vector.VectorSchemaRoot;
+import org.apache.arrow.vector.VectorUnloader;
+import org.apache.arrow.vector.dictionary.Dictionary;
+import org.apache.arrow.vector.dictionary.DictionaryProvider;
+import org.apache.arrow.vector.ipc.ArrowReader;
+import org.apache.arrow.vector.ipc.message.ArrowRecordBatch;
+import org.apache.arrow.vector.types.pojo.ArrowType;
+import org.apache.arrow.vector.types.pojo.Field;
+import org.apache.arrow.vector.types.pojo.Schema;
+import org.junit.jupiter.api.Test;
+
+// Regression test for https://github.com/apache/arrow-java/issues/759
+final class ExceptionTest {
+  @Test
+  public void testException() throws IOException {
+    final Schema schema =
+        new Schema(Collections.singletonList(Field.nullable("ints", new ArrowType.Int(32, true))));
+    final List<Object> batches = new ArrayList<>();
+
+    try (BufferAllocator allocator = new RootAllocator();
+         VectorSchemaRoot root = VectorSchemaRoot.create(schema, allocator)) {
+
+      final String exceptionMessage = "This is a message for testing exception.";
+
+      RuntimeException exToThrow = new RuntimeException(exceptionMessage);
+      batches.add(exToThrow);
+
+      StringWriter sw = new StringWriter();
+      PrintWriter pw = new PrintWriter(sw);
+      exToThrow.printStackTrace(pw);
+      final String expectExceptionMessage = sw.toString();
+
+      ArrowReader source = new ExceptionMemoryArrowReader(allocator, schema, batches);
+
+      try (final ArrowArrayStream stream = ArrowArrayStream.allocateNew(allocator);
+           final VectorSchemaRoot importRoot = VectorSchemaRoot.create(schema, allocator)) {
+        final VectorLoader loader = new VectorLoader(importRoot);
+        Data.exportArrayStream(allocator, source, stream);
+
+        try (final ArrowReader reader = Data.importArrayStream(allocator, stream)) {
+          IOException jniException = catchThrowableOfType(IOException.class, reader::loadNextBatch);
+          final String jniMessage = jniException.getMessage();
+          assertThat(jniMessage.endsWith(expectExceptionMessage + "}"));
+        }
+      }
+    }
+  }
+
+  static class ExceptionMemoryArrowReader extends ArrowReader {
+    private final Schema schema;
+    private final List<Object> batches; // set ArrowRecordBatch or Exception
+    private final DictionaryProvider provider;
+    private int nextBatch;
+
+    ExceptionMemoryArrowReader(
+        BufferAllocator allocator,
+        Schema schema,
+        List<Object> batches) {
+      super(allocator);
+      this.schema = schema;
+      this.batches = batches;
+      this.provider = new CDataDictionaryProvider();
+      this.nextBatch = 0;
+    }
+
+    @Override
+    public Dictionary lookup(long id) {
+      return provider.lookup(id);
+    }
+
+    @Override
+    public Set<Long> getDictionaryIds() {
+      return provider.getDictionaryIds();
+    }
+
+    @Override
+    public Map<Long, Dictionary> getDictionaryVectors() {
+      return getDictionaryIds().stream()
+          .collect(Collectors.toMap(Function.identity(), this::lookup));
+    }
+
+    @Override
+    public boolean loadNextBatch() throws IOException {
+      if (nextBatch < batches.size()) {
+        Object object = batches.get(nextBatch++);
+        if (object instanceof RuntimeException) {
+          throw (RuntimeException) object;
+        }
+        VectorLoader loader = new VectorLoader(getVectorSchemaRoot());
+        loader.load((ArrowRecordBatch) object);
+        return true;
+      }
+      return false;
+    }
+
+    @Override
+    public long bytesRead() {
+      return 0;
+    }
+
+    @Override
+    protected void closeReadSource() throws IOException {
+      try {
+        for (Object object : batches) {
+          if (object instanceof ArrowRecordBatch) {
+            ArrowRecordBatch batch = (ArrowRecordBatch) object;
+            batch.close();
+          }
+        }
+      } catch (Exception e) {
+        throw new IOException(e);
+      }
+    }
+
+    @Override
+    protected Schema readSchema() {
+      return schema;
+    }
+  }
+}