Add snippets for JDBC using Managed I/O by shunping · Pull Request #10239 · GoogleCloudPlatform/java-docs-samples

shunping · 2026-03-03T04:37:43Z

Description

Add code snippets for reading and writing to PostgreSQL database using the Dataflow managed I/O transform.

Also update Beam version in these code snippets from 2.67.0 to 2.70.0.

Part of the work in internal bug: 427973384

Checklist

snippet-bot · 2026-03-03T04:37:48Z

Here is the summary of changes.

You are about to add 2 region tags.

dataflow/snippets/src/main/java/com/example/dataflow/PostgresRead.java:19, tag dataflow_postgres_read
dataflow/snippets/src/main/java/com/example/dataflow/PostgresWrite.java:19, tag dataflow_postgres_write

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gemini-code-assist · 2026-03-03T04:38:54Z

Summary of Changes

Hello, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request adds code snippets demonstrating how to use Dataflow's Managed I/O transform to interact with a PostgreSQL database. It includes examples for both reading from and writing to a PostgreSQL database, along with corresponding integration tests to ensure the functionality works as expected. The changes also involve updating the project's pom.xml file to include the necessary dependencies.

Highlights

Managed I/O Integration: This PR introduces code snippets for reading from and writing to a PostgreSQL database using Dataflow's Managed I/O transform.
New Code Samples: It adds two new code samples: PostgresRead.java for reading data and PostgresWrite.java for writing data to a PostgreSQL database.
Integration Tests: The PR includes integration tests (PostgresReadIT.java and PostgresWriteIT.java) that use Testcontainers to run a containerized PostgreSQL instance for testing.
Dependency Updates: The pom.xml file is updated to include dependencies for JDBC, PostgreSQL, and Testcontainers, as well as updating the Apache Beam version.

Activity

New code snippets for reading and writing to PostgreSQL using Dataflow managed I/O transform were added.
Integration tests were added to verify the functionality of the new code snippets.
The pom.xml file was updated to include necessary dependencies and update the Apache Beam version.

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shunping · 2026-03-03T04:39:44Z

r: @VeronicaWasson @chamikaramj

gemini-code-assist

Code Review

This pull request adds new code snippets for reading from and writing to a PostgreSQL database using Dataflow's Managed I/O. The changes include updating the pom.xml with necessary dependencies and adding new Java classes for the pipelines and their integration tests. My review focuses on improving dependency management in pom.xml and enhancing code readability in the new Java classes. Overall, the changes are well-structured and the new snippets are a valuable addition.

dataflow/snippets/pom.xml

dataflow/snippets/src/main/java/com/example/dataflow/PostgresRead.java

dataflow/snippets/src/test/java/com/example/dataflow/PostgresReadIT.java

dataflow/snippets/src/test/java/com/example/dataflow/PostgresWriteIT.java

chamikaramj

Thanks. LGTM.

For my knowledge, how/when are the ITs introduced here are executed ?

shunping · 2026-03-03T22:05:17Z

Thanks. LGTM.

For my knowledge, how/when are the ITs introduced here are executed ?

Regarding how, I run mvn clean verify under dataflow/snippets. That will run all IT tests under the folder.

For when, I am not sure. I only see there were two kokoro presumit jobs running after I pushed my PR. Other than that, I think @VeronicaWasson can explain more in detail.

tarun-google · 2026-03-05T16:14:14Z

LGTM, reviewed Iceberg relevant Modifications.

tarun-google · 2026-03-05T16:17:43Z

I do not think there is an github action to run IT periodically in this repo. So, people committing the new changes notices issues.

shuesc1

Several nits, otherwise LGTM

shuesc1 · 2026-03-05T17:17:36Z

dataflow/snippets/src/main/java/com/example/dataflow/PostgresRead.java

+
+    void setPassword(String value);
+
+    @Description("Path to write the output file")


Add period at end to match other strings. Also is this a local path, GCS, other? Might be worth being explicit about that unless it's clear / widely known.

shuesc1 · 2026-03-05T17:19:30Z

dataflow/snippets/src/main/java/com/example/dataflow/PostgresRead.java

+public class PostgresRead {
+
+  public interface Options extends PipelineOptions {
+    @Description("The jdbc url of PostgreSQL database to read from.")


"The jdbc url" -> "The JDBC URL"

shuesc1 · 2026-03-05T17:46:38Z

dataflow/snippets/src/main/java/com/example/dataflow/PostgresRead.java

+    // Build the pipeline.
+    var pipeline = Pipeline.create(options);
+    pipeline
+        // Read data from Postgres database via managed io.


Options, depending on which makes most sense:
Read data from a Postgres database using Managed I/O.
Read data from a Postgres database using managed IO.

shuesc1 · 2026-03-05T17:47:21Z

dataflow/snippets/src/main/java/com/example/dataflow/PostgresWrite.java

+              .build());
+
+  public interface Options extends PipelineOptions {
+    @Description("The jdbc url of PostgreSQL database to write to.")


shuesc1 · 2026-03-05T17:47:49Z

dataflow/snippets/src/main/java/com/example/dataflow/PostgresWrite.java

+        // Create data to write to Postgres.
+        .apply(Create.of(ROWS))
+        .setRowSchema(INPUT_SCHEMA)
+        // Write rows to Postgres database via managed io.


same comment as other file

shuesc1 · 2026-03-05T17:48:07Z

dataflow/snippets/src/test/java/com/example/dataflow/PostgresReadIT.java

+  public void setUp() throws Exception {
+    postgres.start();
+
+    // Initialize the database with table and data


add period at end

shuesc1 · 2026-03-05T17:48:27Z

dataflow/snippets/src/test/java/com/example/dataflow/PostgresReadIT.java

+
+  @Test
+  public void testPostgresRead() throws IOException {
+    // Execute the Beam pipeline


period at end

shuesc1 · 2026-03-05T17:50:26Z

dataflow/snippets/src/test/java/com/example/dataflow/PostgresWriteIT.java

+
+  @Test
+  public void testPostgresWrite() throws Exception {
+    // Execute the Beam pipeline


add period at end

shuesc1 · 2026-03-05T17:50:58Z

dataflow/snippets/src/test/java/com/example/dataflow/PostgresWriteIT.java

+  public void setUp() throws Exception {
+    postgres.start();
+
+    // Pre-create the table so the Managed I/O can find it.


"Pre-create" sounds a little off to me. I think just "Create" is fine to convey the same meaning.

shunping added 5 commits March 2, 2026 21:50

Fix missing symbol error while upgrading beam to 2.69.

3c15a74

Add an example for reading from postgres via managed io.

e518462

Add an example for write to postgres via managed io.

dd86fb7

Reformat using google-java-format

91593b6

Minor change on table names.

57d2b5a

shunping requested review from a team and yoshi-approver as code owners March 3, 2026 04:37

product-auto-label bot added samples Issues that are directly related to samples. api: dataflow Issues related to the Dataflow API. labels Mar 3, 2026

gemini-code-assist bot reviewed Mar 3, 2026

View reviewed changes

shunping added 2 commits March 3, 2026 11:00

Fix iceberg test due to beam version upgrade.

be51dc1

Address reviews.

e21d4d6

chamikaramj approved these changes Mar 3, 2026

View reviewed changes

shuesc1 reviewed Mar 5, 2026

View reviewed changes


		void setPassword(String value);

		@Description("Path to write the output file")

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shunping commented Mar 3, 2026 •

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