Prepare samples repo for connector sync (#224)

## Summary
Prepare the samples repo structure to enable automated syncing of
examples from connector repos.

## Changes

### Java pgjdbc
- Rename package from `org.example` to `software.amazon.dsql.examples`
(matching connector)
- Switch from Maven to Gradle build system (matching connector)
- Add gradle wrapper for standalone builds
- Update workflow to use `./gradlew test` instead of `mvn test`

### Python asyncpg (NEW)
- Add new `python/asyncpg/` folder with examples from connector
- Add integration test workflow for asyncpg

## Files Changed
| Type | Description |
|------|-------------|
| Renamed | Java files moved to new package path |
| Deleted | `pom.xml` (replaced by Gradle) |
| Added | Gradle wrapper files |
| Added | `python/asyncpg/` folder with examples |
| Added | `python-asyncpg-integ-tests.yml` workflow |
| Modified | `java-pgjdbc-integ-tests.yml` to use Gradle |

## Testing
- Java compiles successfully with Gradle
- Python files pass syntax check
- Integration tests will run in CI

## Motivation
This aligns the samples repo structure with the connector repos to
enable automated syncing of examples. The `ExampleWithNoConnector` files
remain samples-only and will not be overwritten by sync.

Co-authored-by: Aleksandar Maksimovic <alemaksi@amazon.com>

Author: amaksimo

.github/workflows/java-pgjdbc-integ-tests.yml

@@ -40,7 +40,7 @@ jobs:
         java-version: '17'
         distribution: 'corretto'
         architecture: x64
-        cache: maven
+        cache: gradle
 
     - name: Configure AWS Credentials
       uses: aws-actions/configure-aws-credentials@v4
@@ -54,8 +54,4 @@ jobs:
         CLUSTER_ENDPOINT: ${{ secrets.JAVA_PGJDBC_CLUSTER_ENDPOINT }}
         CLUSTER_USER: admin
         REGION: ${{ secrets.JAVA_PGJDBC_CLUSTER_REGION }}
-      run: |
-        mvn validate
-        mvn initialize
-        mvn compile
-        mvn test
+      run: ./gradlew test

.github/workflows/python-asyncpg-integ-tests.yml

@@ -0,0 +1,70 @@
+name: Python asyncpg integration tests
+
+permissions: {}
+
+on:
+  push:
+    branches: [ main ]
+    paths:
+      - 'python/asyncpg/**'
+      - '.github/workflows/python-asyncpg-integ-tests.yml'
+  pull_request:
+    branches: [ main ]
+    paths:
+      - 'python/asyncpg/**'
+      - '.github/workflows/python-asyncpg-integ-tests.yml'
+  # Give us a button to allow running the workflow on demand for testing.
+  workflow_dispatch:
+    inputs:
+      tags:
+        description: 'Manual Workflow Run'
+        required: false
+        type: string
+
+jobs:
+  python-asyncpg-integ-test:
+    runs-on: ubuntu-latest
+    permissions:
+      id-token: write # required by aws-actions/configure-aws-credentials
+    concurrency:
+      # Ensure only 1 job uses the workflow cluster at a time.
+      group: ${{ github.workflow }}
+
+    steps:
+    - name: Checkout code
+      uses: actions/checkout@v4
+
+    - name: Set up Python
+      uses: actions/setup-python@v5
+      with:
+        python-version: '3.10'
+
+    - name: Cache pip packages
+      uses: actions/cache@v4
+      with:
+        path: ~/.cache/pip
+        key: ${{ runner.os }}-pip-${{ hashFiles('**/requirements.txt') }}
+        restore-keys: |
+          ${{ runner.os }}-pip-
+
+    - name: Configure AWS Credentials
+      uses: aws-actions/configure-aws-credentials@v4
+      with:
+        role-to-assume: ${{ secrets.PYTHON_IAM_ROLE }}
+        aws-region: us-east-1
+
+    - name: Configure and run integration for asyncpg - admin
+      working-directory: ./python/asyncpg
+      env:
+        CLUSTER_USER: "admin"
+        CLUSTER_ENDPOINT: ${{ secrets.PYTHON_PSYCOPG3_CLUSTER_ENDPOINT }}
+      run: |
+        python3 -m venv .venv
+        source .venv/bin/activate
+        pip install --upgrade pip
+        pip install --force-reinstall -r requirements.txt
+        python3 -c "import boto3; print(boto3.__version__)"
+        pip list
+        echo "$GITHUB_WORKSPACE" >> $GITHUB_PATH
+        wget https://www.amazontrust.com/repository/AmazonRootCA1.pem -O root.pem
+        pytest

java/pgjdbc/README.md

@@ -56,9 +56,7 @@ connections should be used where possible to ensure data security during transmi
    ```bash
    java -version
 
-* Build Tool (Maven or Gradle)
-   - _Maven_: Ensure Maven is installed if that is your preferred option. You can download it from the [official website](https://maven.apache.org/download.cgi).
-   - _Gradle_: Ensure Gradle is installed if that is your preferred option. You can download it from the [official website](https://gradle.org/install/).
+* Gradle: This example uses the Gradle wrapper included in the repository, so no separate installation is required.
 * AWS SDK: Ensure that you setup the latest version of the AWS Java SDK [official website](https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/setup.html)
 * You must have an Aurora DSQL cluster. For information about creating an Aurora DSQL cluster, see the
   [Getting started with Aurora DSQL](https://docs.aws.amazon.com/aurora-dsql/latest/userguide/getting-started.html)
@@ -95,18 +93,15 @@ export CLUSTER_ENDPOINT="<your endpoint>"
 
 Run the example:
 
-  - _Maven_:
-
-      ```bash
-      mvn compile
-      mvn test
-      ```
+```bash
+./gradlew run
+```
 
-  - _Gradle_:
+Run the tests:
 
-      ```bash
-      gradle run
-      ```
+```bash
+./gradlew test
+```
 
 
 The example contains comments explaining the code and the operations being performed.
@@ -122,4 +117,4 @@ The example contains comments explaining the code and the operations being perfo
 
 Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
 
-SPDX-License-Identifier: MIT-0
+SPDX-License-Identifier: Apache-2.0

java/pgjdbc/build.gradle.kts

@@ -1,3 +1,6 @@
+// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+
 import org.gradle.api.tasks.testing.logging.TestExceptionFormat
 
 plugins {
@@ -6,18 +9,22 @@ plugins {
 }
 
 application {
-    mainClass = "org.example.Example"
+    mainClass = "software.amazon.dsql.examples.ExamplePreferred"
 }
 
-group = "org.example"
+group = "software.amazon.dsql.examples"
 version = "1.0-SNAPSHOT"
 
 repositories {
     mavenCentral()
 }
 
 dependencies {
+    implementation("com.zaxxer:HikariCP:5.1.0")
     implementation("software.amazon.dsql:aurora-dsql-jdbc-connector:1.2.0")
+    // AWS SDK dependencies for SDK-only example (ExampleWithNoConnector)
+    implementation("software.amazon.awssdk:dsql:2.31.32")
+    implementation("org.postgresql:postgresql:42.7.7")
 
     testImplementation(platform("org.junit:junit-bom:5.10.0"))
     testImplementation("org.junit.jupiter:junit-jupiter")
@@ -41,4 +48,4 @@ tasks.withType<Test> {
 
 tasks.withType<JavaExec> {
     this.enableAssertions = true
-}
+}

java/pgjdbc/gradle/wrapper/gradle-wrapper.jar

@@ -0,0 +1,7 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-9.1.0-bin.zip
+networkTimeout=10000
+validateDistributionUrl=true
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists