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https://issues.apache.org/jira/browse/BEAM-4160?focusedWorklogId=94919&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-94919
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ASF GitHub Bot logged work on BEAM-4160:
----------------------------------------
Author: ASF GitHub Bot
Created on: 25/Apr/18 02:10
Start Date: 25/Apr/18 02:10
Worklog Time Spent: 10m
Work Description: kennknowles closed pull request #5120: [BEAM-4160] Add
JsonToRow transform
URL: https://github.com/apache/beam/pull/5120
This is a PR merged from a forked repository.
As GitHub hides the original diff on merge, it is displayed below for
the sake of provenance:
As this is a foreign pull request (from a fork), the diff is supplied
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diff --git
a/sdks/java/core/src/main/java/org/apache/beam/sdk/transforms/JsonToRow.java
b/sdks/java/core/src/main/java/org/apache/beam/sdk/transforms/JsonToRow.java
new file mode 100644
index 00000000000..eb3011df4d4
--- /dev/null
+++ b/sdks/java/core/src/main/java/org/apache/beam/sdk/transforms/JsonToRow.java
@@ -0,0 +1,126 @@
+/*
+ * 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.beam.sdk.transforms;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.module.SimpleModule;
+import java.io.IOException;
+import javax.annotation.Nullable;
+import org.apache.beam.sdk.annotations.Experimental;
+import org.apache.beam.sdk.schemas.Schema;
+import org.apache.beam.sdk.schemas.Schema.TypeName;
+import org.apache.beam.sdk.util.RowJsonDeserializer;
+import org.apache.beam.sdk.values.PCollection;
+import org.apache.beam.sdk.values.Row;
+
+/**
+ * <i>Experimental</i>
+ *
+ * <p>Creates a {@link PTransform} to convert input JSON objects to {@link Row
Rows}
+ * with given {@link Schema}.
+ *
+ * <p>Currently supported {@link Schema} field types are: <ul> <li>{@link
Schema.TypeName#BYTE}</li>
+ * <li>{@link Schema.TypeName#INT16}</li> <li>{@link
Schema.TypeName#INT32}</li> <li>{@link
+ * Schema.TypeName#INT64}</li> <li>{@link Schema.TypeName#FLOAT}</li>
<li>{@link
+ * Schema.TypeName#DOUBLE}</li> <li>{@link Schema.TypeName#BOOLEAN}</li>
<li>{@link
+ * Schema.TypeName#STRING}</li> </ul>
+ *
+ * <p>For specifics of JSON deserialization see {@link RowJsonDeserializer}.
+ *
+ * <p>Conversion is strict, with minimal type coercion:
+ *
+ * <p>Booleans are only parsed from {@code true} or {@code false} literals,
not from {@code "true"}
+ * or {@code "false"} strings or any other values (exception is thrown in
these cases).
+ *
+ * <p>If a JSON number doesn't fit into the corresponding schema field type,
an exception is be
+ * thrown. Strings are not auto-converted to numbers. Floating point numbers
are not auto-converted
+ * to integral numbers. Precision loss also causes exceptions.
+ *
+ * <p>Only JSON string values can be parsed into {@link TypeName#STRING}.
Numbers, booleans are not
+ * automatically converted, exceptions are thrown in these cases.
+ *
+ * <p>If a schema field is missing from the JSON value, an exception will be
thrown.
+ *
+ * <p>Explicit {@code null} literals are allowed in JSON objects. No other
values are parsed into
+ * {@code null}.
+ */
+@Experimental
+public class JsonToRow {
+
+ public static PTransform<PCollection<? extends String>, PCollection<Row>>
withSchema(
+ Schema rowSchema) {
+ return JsonToRowFn.forSchema(rowSchema);
+ }
+
+ static class JsonToRowFn extends PTransform<PCollection<? extends String>,
PCollection<Row>> {
+ private transient volatile @Nullable ObjectMapper objectMapper;
+ private Schema schema;
+
+ static JsonToRowFn forSchema(Schema rowSchema) {
+ return new JsonToRowFn(rowSchema);
+ }
+
+ private JsonToRowFn(Schema schema) {
+ this.schema = schema;
+ }
+
+ @Override
+ public PCollection<Row> expand(PCollection<? extends String> jsonStrings) {
+ return jsonStrings
+ .apply(
+ ParDo.of(
+ new DoFn<String, Row>() {
+ @ProcessElement
+ public void processElement(ProcessContext context) {
+ context.output(jsonToRow(context.element()));
+ }
+ }))
+ .setCoder(schema.getRowCoder());
+ }
+
+ private Row jsonToRow(String jsonString) {
+ try {
+ return objectMapper().readValue(jsonString, Row.class);
+ } catch (IOException e) {
+ throw new IllegalArgumentException("Unable to parse json object: " +
jsonString, e);
+ }
+ }
+
+ private ObjectMapper objectMapper() {
+ if (this.objectMapper == null) {
+ synchronized (this) {
+ if (this.objectMapper == null) {
+ this.objectMapper =
newObjectMapperWith(RowJsonDeserializer.forSchema(this.schema));
+ }
+ }
+ }
+
+ return this.objectMapper;
+ }
+
+ private static ObjectMapper newObjectMapperWith(RowJsonDeserializer
deserializer) {
+ SimpleModule module = new SimpleModule("rowDeserializationModule");
+ module.addDeserializer(Row.class, deserializer);
+
+ ObjectMapper objectMapper = new ObjectMapper();
+ objectMapper.registerModule(module);
+
+ return objectMapper;
+ }
+ }
+}
diff --git
a/sdks/java/core/src/test/java/org/apache/beam/sdk/transforms/JsonToRowTest.java
b/sdks/java/core/src/test/java/org/apache/beam/sdk/transforms/JsonToRowTest.java
new file mode 100644
index 00000000000..021bf287426
--- /dev/null
+++
b/sdks/java/core/src/test/java/org/apache/beam/sdk/transforms/JsonToRowTest.java
@@ -0,0 +1,94 @@
+/*
+ * 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.beam.sdk.transforms;
+
+import java.io.Serializable;
+import org.apache.beam.sdk.schemas.Schema;
+import org.apache.beam.sdk.testing.NeedsRunner;
+import org.apache.beam.sdk.testing.PAssert;
+import org.apache.beam.sdk.testing.TestPipeline;
+import org.apache.beam.sdk.values.PCollection;
+import org.apache.beam.sdk.values.Row;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.experimental.categories.Category;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+/**
+ * Unit tests for {@link JsonToRow}.
+ */
+@RunWith(JUnit4.class)
+public class JsonToRowTest implements Serializable {
+
+ private static final boolean NOT_NULLABLE = false;
+
+ @Rule
+ public transient TestPipeline pipeline = TestPipeline.create();
+
+ @Test
+ @Category(NeedsRunner.class)
+ public void testParsesRows() throws Exception {
+ Schema personSchema =
+ Schema
+ .builder()
+ .addStringField("name", NOT_NULLABLE)
+ .addInt32Field("height", NOT_NULLABLE)
+ .addBooleanField("knowsJavascript", NOT_NULLABLE)
+ .build();
+
+ PCollection<String> jsonPersons = pipeline
+ .apply(
+ "jsonPersons",
+ Create.of(
+ jsonPerson("person1", "80", "true"),
+ jsonPerson("person2", "70", "false"),
+ jsonPerson("person3", "60", "true"),
+ jsonPerson("person4", "50", "false"),
+ jsonPerson("person5", "40", "true")));
+
+ PCollection<Row> personRows =
+ jsonPersons
+ .apply(JsonToRow.withSchema(personSchema))
+ .setCoder(personSchema.getRowCoder());
+
+ PAssert
+ .that(personRows)
+ .containsInAnyOrder(
+ row(personSchema, "person1", 80, true),
+ row(personSchema, "person2", 70, false),
+ row(personSchema, "person3", 60, true),
+ row(personSchema, "person4", 50, false),
+ row(personSchema, "person5", 40, true));
+
+ pipeline.run();
+ }
+
+ private String jsonPerson(String name, String height, String knowsJs) {
+ return
+ "{\n"
+ + " \"name\": \"" + name + "\",\n"
+ + " \"height\": " + height + ",\n"
+ + " \"knowsJavascript\": " + knowsJs + "\n"
+ + "}";
+ }
+
+ private Row row(Schema schema, Object... values) {
+ return Row.withSchema(schema).addValues(values).build();
+ }
+}
diff --git
a/sdks/java/extensions/sql/src/test/java/org/apache/beam/sdk/extensions/sql/JsonToRowSqlTest.java
b/sdks/java/extensions/sql/src/test/java/org/apache/beam/sdk/extensions/sql/JsonToRowSqlTest.java
new file mode 100644
index 00000000000..eb7b721b5c1
--- /dev/null
+++
b/sdks/java/extensions/sql/src/test/java/org/apache/beam/sdk/extensions/sql/JsonToRowSqlTest.java
@@ -0,0 +1,90 @@
+/*
+ * 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.beam.sdk.extensions.sql;
+
+import org.apache.beam.sdk.schemas.Schema;
+import org.apache.beam.sdk.testing.PAssert;
+import org.apache.beam.sdk.testing.TestPipeline;
+import org.apache.beam.sdk.transforms.Create;
+import org.apache.beam.sdk.transforms.JsonToRow;
+import org.apache.beam.sdk.values.PCollection;
+import org.apache.beam.sdk.values.Row;
+import org.junit.Rule;
+import org.junit.Test;
+
+/**
+ * JsonToRowSqlTest.
+ */
+public class JsonToRowSqlTest {
+ private static final boolean NOT_NULLABLE = false;
+
+ @Rule
+ public transient TestPipeline pipeline = TestPipeline.create();
+
+ @Test
+ public void testParsesRows() throws Exception {
+ Schema personSchema =
+ Schema
+ .builder()
+ .addStringField("name", NOT_NULLABLE)
+ .addInt32Field("height", NOT_NULLABLE)
+ .addBooleanField("knowsJavascript", NOT_NULLABLE)
+ .build();
+
+ PCollection<String> jsonPersons =
+ pipeline.apply(
+ Create
+ .of(
+ jsonPerson("person1", "80", "true"),
+ jsonPerson("person2", "70", "false"),
+ jsonPerson("person3", "60", "true"),
+ jsonPerson("person4", "50", "false"),
+ jsonPerson("person5", "40", "true")));
+
+ Schema resultSchema =
+ Schema
+ .builder()
+ .addInt32Field("avg_height", NOT_NULLABLE)
+ .build();
+
+ PCollection<Row> sqlResult =
+ jsonPersons
+ .apply(JsonToRow.withSchema(personSchema))
+ .apply(BeamSql.query("SELECT AVG(height) as avg_height FROM
PCOLLECTION"));
+
+ PAssert
+ .that(sqlResult)
+ .containsInAnyOrder(
+ row(resultSchema, 60));
+
+ pipeline.run();
+ }
+
+ private String jsonPerson(String name, String height, String knowsJs) {
+ return
+ "{\n"
+ + " \"name\": \"" + name + "\",\n"
+ + " \"height\": " + height + ",\n"
+ + " \"knowsJavascript\": " + knowsJs + "\n"
+ + "}";
+ }
+
+ private Row row(Schema schema, Object... values) {
+ return Row.withSchema(schema).addValues(values).build();
+ }
+}
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Issue Time Tracking
-------------------
Worklog Id: (was: 94919)
Time Spent: 1h 10m (was: 1h)
> Convert JSON objects to Rows
> ----------------------------
>
> Key: BEAM-4160
> URL: https://issues.apache.org/jira/browse/BEAM-4160
> Project: Beam
> Issue Type: New Feature
> Components: dsl-sql, sdk-java-core
> Reporter: Anton Kedin
> Assignee: Anton Kedin
> Priority: Major
> Time Spent: 1h 10m
> Remaining Estimate: 0h
>
> Automate conversion of JSON objects to Rows to reduce overhead for querying
> JSON-based sources
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