Add Java Csv and Json write pipeline examples

Java/pom.xml

@@ -354,6 +354,20 @@
       <version>${beam.version}</version>
     </dependency>
 
+    <!-- Adds a dependency on the Beam CSV IO module. -->
+    <dependency>
+      <groupId>org.apache.beam</groupId>
+      <artifactId>beam-sdks-java-io-csv</artifactId>
+      <version>${beam.version}</version>
+    </dependency>
+
+    <!-- Adds a dependency on the Beam JSON IO module. -->
+    <dependency>
+      <groupId>org.apache.beam</groupId>
+      <artifactId>beam-sdks-java-io-json</artifactId>
+      <version>${beam.version}</version>
+    </dependency>
+
     <!-- Dependencies below this line are specific dependencies needed by the examples code. -->
     <dependency>
       <groupId>com.google.api-client</groupId>

Java/src/main/java/gcs/WriteCsvIO.java

@@ -0,0 +1,92 @@
+/*
+ * Copyright 2024 Google LLC
+ *
+ * Licensed 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
+ *
+ *     https://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 gcs;
+
+import org.apache.beam.sdk.Pipeline;
+import org.apache.beam.sdk.io.csv.CsvIO;
+import org.apache.beam.sdk.options.Description;
+import org.apache.beam.sdk.options.PipelineOptions;
+import org.apache.beam.sdk.options.PipelineOptionsFactory;
+import org.apache.beam.sdk.options.Validation;
+import org.apache.beam.sdk.schemas.JavaFieldSchema;
+import org.apache.beam.sdk.schemas.annotations.DefaultSchema;
+import org.apache.beam.sdk.transforms.Create;
+import org.apache.commons.csv.CSVFormat;
+
+import java.io.Serializable;
+import java.util.Arrays;
+import java.util.List;
+
+/**
+ * Pipeline for writing data to CSV files using the {@code CsvIO.write()} transform.
+ */
+public class WriteCsvIO {
+
+    /** Represents an Example CSV record. */
+    @DefaultSchema(JavaFieldSchema.class)
+    public static class ExampleRecord implements Serializable {
+        public int id;
+        public String name;
+
+        public ExampleRecord() {
+        }
+
+        public ExampleRecord(int id, String name) {
+            this.id = id;
+            this.name = name;
+        }
+    }
+
+    /**
+     * Pipeline options for write to CSV files.
+     */
+    public interface WriteCsvOptions extends PipelineOptions {
+
+        @Description("A file path prefix to write CSV files to")
+        @Validation.Required
+        String getFilePathPrefix();
+
+        void setFilePathPrefix(String filePathPrefix);
+    }
+
+    public static void main(String[] args) {
+        WriteCsvOptions options =
+                PipelineOptionsFactory.fromArgs(args)
+                        .withValidation().as(WriteCsvOptions.class);
+
+        Pipeline p = Pipeline.create(options);
+
+        List<ExampleRecord> rows =
+            Arrays.asList(
+                new ExampleRecord(1, "Charles"),
+                new ExampleRecord(2, "Alice"),
+                new ExampleRecord(3, "Bob"),
+                new ExampleRecord(4, "Amanda"),
+                new ExampleRecord(5, "Alex"),
+                new ExampleRecord(6, "Eliza"));
+
+        CSVFormat csvFormat =
+            CSVFormat.DEFAULT.withHeaderComments("example comment 1", "example comment 2")
+                .withCommentMarker('#');
+
+        p.apply("Create", Create.of(rows))
+            .apply(
+                "Write to CSV",
+                    CsvIO.<ExampleRecord>write(options.getFilePathPrefix(), csvFormat)
+                        .withNumShards(1));
+        p.run();
+    }
+}

Java/src/main/java/gcs/WriteJsonIO.java

@@ -0,0 +1,87 @@
+/*
+ * Copyright 2024 Google LLC
+ *
+ * Licensed 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
+ *
+ *     https://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 gcs;
+
+import org.apache.beam.sdk.Pipeline;
+import org.apache.beam.sdk.io.json.JsonIO;
+import org.apache.beam.sdk.options.Description;
+import org.apache.beam.sdk.options.PipelineOptions;
+import org.apache.beam.sdk.options.PipelineOptionsFactory;
+import org.apache.beam.sdk.options.Validation;
+import org.apache.beam.sdk.schemas.JavaFieldSchema;
+import org.apache.beam.sdk.schemas.annotations.DefaultSchema;
+import org.apache.beam.sdk.transforms.Create;
+
+import java.io.Serializable;
+import java.util.Arrays;
+import java.util.List;
+
+/**
+ * Pipeline for writing data to JSON files using the {@code JsonIO.write()} transform.
+ */
+public class WriteJsonIO {
+
+    /** Represents an Example JSON record. */
+    @DefaultSchema(JavaFieldSchema.class)
+    public static class ExampleRecord implements Serializable {
+        public int id;
+        public String name;
+
+        public ExampleRecord() {
+        }
+
+        public ExampleRecord(int id, String name) {
+            this.id = id;
+            this.name = name;
+        }
+    }
+
+    /**
+     * Pipeline options for write to JSON files.
+     */
+    public interface WriteJsonOptions extends PipelineOptions {
+
+        @Description("A file path prefix to write JSON files to")
+        @Validation.Required
+        String getFilePathPrefix();
+
+        void setFilePathPrefix(String filePathPrefix);
+    }
+
+    public static void main(String[] args) {
+        WriteJsonOptions options =
+                PipelineOptionsFactory.fromArgs(args)
+                        .withValidation().as(WriteJsonOptions.class);
+
+        Pipeline p = Pipeline.create(options);
+
+        List<ExampleRecord> rows =
+            Arrays.asList(
+                new ExampleRecord(1, "Charles"),
+                new ExampleRecord(2, "Alice"),
+                new ExampleRecord(3, "Bob"),
+                new ExampleRecord(4, "Amanda"),
+                new ExampleRecord(5, "Alex"),
+                new ExampleRecord(6, "Eliza"));
+
+        p.apply("Create", Create.of(rows))
+            .apply(
+                "Write to JSON",
+                    JsonIO.<ExampleRecord>write(options.getFilePathPrefix())
+                        .withNumShards(1));
+        p.run();
+    }
+}