Create CsvIOParseResult (#31706)

sdks/java/io/csv/src/main/java/org/apache/beam/sdk/io/csv/providers/CsvIOParseResult.java

@@ -0,0 +1,86 @@
+/*
+ * 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.io.csv.providers;
+
+import java.util.Map;
+import org.apache.beam.sdk.Pipeline;
+import org.apache.beam.sdk.io.csv.CsvIOParseError;
+import org.apache.beam.sdk.transforms.PTransform;
+import org.apache.beam.sdk.values.PCollection;
+import org.apache.beam.sdk.values.PCollectionTuple;
+import org.apache.beam.sdk.values.PInput;
+import org.apache.beam.sdk.values.POutput;
+import org.apache.beam.sdk.values.PValue;
+import org.apache.beam.sdk.values.TupleTag;
+import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.collect.ImmutableMap;
+
+/**
+ * The {@link T} and {@link CsvIOParseError} {@link PCollection} results of parsing CSV records. Use
+ * {@link #getOutput()} and {@link #getErrors()} to apply these results in a pipeline.
+ */
+public class CsvIOParseResult<T> implements POutput {
+
+  static <T> CsvIOParseResult<T> of(
+      TupleTag<T> outputTag, TupleTag<CsvIOParseError> errorTag, PCollectionTuple pct) {
+    return new CsvIOParseResult<>(outputTag, errorTag, pct);
+  }
+
+  private final Pipeline pipeline;
+  private final TupleTag<T> outputTag;
+  private final PCollection<T> output;
+  private final TupleTag<CsvIOParseError> errorTag;
+  private final PCollection<CsvIOParseError> errors;
+
+  private CsvIOParseResult(
+      TupleTag<T> outputTag, TupleTag<CsvIOParseError> errorTag, PCollectionTuple pct) {
+    this.outputTag = outputTag;
+    this.errorTag = errorTag;
+    this.pipeline = pct.getPipeline();
+    this.output = pct.get(outputTag);
+    this.errors = pct.get(errorTag);
+  }
+
+  /** The {@link T} {@link PCollection} as a result of successfully parsing CSV records. */
+  public PCollection<T> getOutput() {
+    return output;
+  }
+
+  /**
+   * The {@link CsvIOParseError} {@link PCollection} as a result of errors associated with parsing
+   * CSV records.
+   */
+  public PCollection<CsvIOParseError> getErrors() {
+    return errors;
+  }
+
+  @Override
+  public Pipeline getPipeline() {
+    return pipeline;
+  }
+
+  @Override
+  public Map<TupleTag<?>, PValue> expand() {
+    return ImmutableMap.of(
+        outputTag, output,
+        errorTag, errors);
+  }
+
+  @Override
+  public void finishSpecifyingOutput(
+      String transformName, PInput input, PTransform<?, ?> transform) {}
+}