davisusanibar commented on a change in pull request #12739: URL: https://github.com/apache/arrow/pull/12739#discussion_r839007111
########## File path: docs/source/java/examples/quickstartguide.rst ########## @@ -0,0 +1,277 @@ +.. 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. + +.. default-domain:: java +.. highlight:: java + +================= +Quick Start Guide +================= + +.. contents:: + +Arrow Java provides several building blocks; ``data types`` describe the types of values; +``ValueVectors`` are sequences of typed values; ``fields`` describe the types of columns in +tabular data; ``schemas`` describe a sequence of columns in tabular data and +``VectorSchemaRoot`` represents tabular data. Arrow also provides ``readers`` and +``writers`` for loading data from and persisting data to storage. + +Create A Value Vector +********************* + +Also known as "arrays" in the columnar format. Represent a one-dimensional +sequence of homogeneous values. + +**Int Vector**: Create an value vector of int32s like this [1, null, 2] + +.. code-block:: Java + + import org.apache.arrow.memory.BufferAllocator; + import org.apache.arrow.memory.RootAllocator; + import org.apache.arrow.vector.IntVector; + + try(BufferAllocator rootAllocator = new RootAllocator(); + IntVector intVector = new IntVector("fixed-size-primitive-layout", rootAllocator)){ + intVector.allocateNew(3); + intVector.set(0,1); + intVector.setNull(1); + intVector.set(2,2); + intVector.setValueCount(3); + System.out.println("Vector created in memory: " + intVector); + } + +**Varchar Vector**: Create an value vector of string like this [one, two, three] + +.. code-block:: Java + + import org.apache.arrow.memory.BufferAllocator; + import org.apache.arrow.memory.RootAllocator; + import org.apache.arrow.vector.VarCharVector; + + try(BufferAllocator rootAllocator = new RootAllocator(); + VarCharVector varCharVector = new VarCharVector("variable-size-primitive-layout", rootAllocator)){ + varCharVector.allocateNew(3); + varCharVector.set(0, "one".getBytes()); + varCharVector.set(1, "two".getBytes()); + varCharVector.set(2, "three".getBytes()); + varCharVector.setValueCount(3); + System.out.println("Vector created in memory: " + varCharVector); + } + +Create A Field +************** + +Fields are used to denote the particular columns of tabular data. + +**Field**: Create a column "document" of string type with metadata. + +.. code-block:: Java + + import org.apache.arrow.vector.types.pojo.ArrowType; + import org.apache.arrow.vector.types.pojo.Field; + import org.apache.arrow.vector.types.pojo.FieldType; + + Map<String, String> metadata = new HashMap<>(); + metadata.put("A", "Id card"); + metadata.put("B", "Passport"); + metadata.put("C", "Visa"); + Field document = new Field("document", new FieldType(true, new ArrowType.Utf8(), /*dictionary*/ null, metadata), /*children*/ null); + +Create A Schema +*************** + +Schema holds a sequence of fields together with some optional metadata. + +**Schema**: Create a schema describing datasets with two columns: +a int32 column "A" and a utf8-encoded string column "B" + +.. code-block:: Java + + import org.apache.arrow.vector.types.pojo.ArrowType; + import org.apache.arrow.vector.types.pojo.Field; + import org.apache.arrow.vector.types.pojo.FieldType; + import org.apache.arrow.vector.types.pojo.Schema; + import static java.util.Arrays.asList; + + Map<String, String> metadata = new HashMap<>(); + metadata.put("K1", "V1"); + metadata.put("K2", "V2"); + Field a = new Field("A", FieldType.nullable(new ArrowType.Int(32, true)), null); + Field b = new Field("B", FieldType.nullable(new ArrowType.Utf8()), null); + Schema schema = new Schema(asList(a, b), metadata); + +Create A VectorSchemaRoot +*************************** + +VectorSchemaRoot is somewhat analogous to tables and record batches in the other +Arrow implementations. Review comment: Added ########## File path: docs/source/java/examples/quickstartguide.rst ########## @@ -0,0 +1,277 @@ +.. 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. + +.. default-domain:: java +.. highlight:: java + +================= +Quick Start Guide +================= + +.. contents:: + +Arrow Java provides several building blocks; ``data types`` describe the types of values; +``ValueVectors`` are sequences of typed values; ``fields`` describe the types of columns in +tabular data; ``schemas`` describe a sequence of columns in tabular data and +``VectorSchemaRoot`` represents tabular data. Arrow also provides ``readers`` and +``writers`` for loading data from and persisting data to storage. + +Create A Value Vector +********************* + +Also known as "arrays" in the columnar format. Represent a one-dimensional +sequence of homogeneous values. + +**Int Vector**: Create an value vector of int32s like this [1, null, 2] + +.. code-block:: Java + + import org.apache.arrow.memory.BufferAllocator; + import org.apache.arrow.memory.RootAllocator; + import org.apache.arrow.vector.IntVector; + + try(BufferAllocator rootAllocator = new RootAllocator(); + IntVector intVector = new IntVector("fixed-size-primitive-layout", rootAllocator)){ Review comment: Changed ########## File path: docs/source/java/examples/quickstartguide.rst ########## @@ -0,0 +1,277 @@ +.. 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. + +.. default-domain:: java +.. highlight:: java + +================= +Quick Start Guide +================= + +.. contents:: + +Arrow Java provides several building blocks; ``data types`` describe the types of values; +``ValueVectors`` are sequences of typed values; ``fields`` describe the types of columns in +tabular data; ``schemas`` describe a sequence of columns in tabular data and +``VectorSchemaRoot`` represents tabular data. Arrow also provides ``readers`` and +``writers`` for loading data from and persisting data to storage. + +Create A Value Vector +********************* + +Also known as "arrays" in the columnar format. Represent a one-dimensional +sequence of homogeneous values. + +**Int Vector**: Create an value vector of int32s like this [1, null, 2] + +.. code-block:: Java + + import org.apache.arrow.memory.BufferAllocator; + import org.apache.arrow.memory.RootAllocator; + import org.apache.arrow.vector.IntVector; + + try(BufferAllocator rootAllocator = new RootAllocator(); + IntVector intVector = new IntVector("fixed-size-primitive-layout", rootAllocator)){ + intVector.allocateNew(3); + intVector.set(0,1); + intVector.setNull(1); + intVector.set(2,2); + intVector.setValueCount(3); + System.out.println("Vector created in memory: " + intVector); + } Review comment: Added ########## File path: docs/source/java/examples/quickstartguide.rst ########## @@ -0,0 +1,277 @@ +.. 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. + +.. default-domain:: java +.. highlight:: java + +================= +Quick Start Guide +================= + +.. contents:: + +Arrow Java provides several building blocks; ``data types`` describe the types of values; +``ValueVectors`` are sequences of typed values; ``fields`` describe the types of columns in +tabular data; ``schemas`` describe a sequence of columns in tabular data and +``VectorSchemaRoot`` represents tabular data. Arrow also provides ``readers`` and +``writers`` for loading data from and persisting data to storage. + +Create A Value Vector +********************* + +Also known as "arrays" in the columnar format. Represent a one-dimensional +sequence of homogeneous values. + +**Int Vector**: Create an value vector of int32s like this [1, null, 2] + +.. code-block:: Java + + import org.apache.arrow.memory.BufferAllocator; + import org.apache.arrow.memory.RootAllocator; + import org.apache.arrow.vector.IntVector; + + try(BufferAllocator rootAllocator = new RootAllocator(); + IntVector intVector = new IntVector("fixed-size-primitive-layout", rootAllocator)){ + intVector.allocateNew(3); + intVector.set(0,1); + intVector.setNull(1); + intVector.set(2,2); + intVector.setValueCount(3); + System.out.println("Vector created in memory: " + intVector); + } + +**Varchar Vector**: Create an value vector of string like this [one, two, three] + +.. code-block:: Java + + import org.apache.arrow.memory.BufferAllocator; + import org.apache.arrow.memory.RootAllocator; + import org.apache.arrow.vector.VarCharVector; + + try(BufferAllocator rootAllocator = new RootAllocator(); + VarCharVector varCharVector = new VarCharVector("variable-size-primitive-layout", rootAllocator)){ + varCharVector.allocateNew(3); + varCharVector.set(0, "one".getBytes()); + varCharVector.set(1, "two".getBytes()); + varCharVector.set(2, "three".getBytes()); + varCharVector.setValueCount(3); + System.out.println("Vector created in memory: " + varCharVector); + } + +Create A Field +************** + +Fields are used to denote the particular columns of tabular data. + +**Field**: Create a column "document" of string type with metadata. + +.. code-block:: Java + + import org.apache.arrow.vector.types.pojo.ArrowType; + import org.apache.arrow.vector.types.pojo.Field; + import org.apache.arrow.vector.types.pojo.FieldType; + + Map<String, String> metadata = new HashMap<>(); + metadata.put("A", "Id card"); + metadata.put("B", "Passport"); + metadata.put("C", "Visa"); + Field document = new Field("document", new FieldType(true, new ArrowType.Utf8(), /*dictionary*/ null, metadata), /*children*/ null); Review comment: Changed -- This is an automated message from the Apache Git Service. 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