Add Java Durable Entity samples

[bachuv]

Purpose

Adding Java Durable Entity samples. Creating the PR as a draft PR until the feature is released in the Durable Java SDK.

Does this introduce a breaking change?

[ ] Yes
[x] No

Pull Request Type

What kind of change does this Pull Request introduce?

[ ] Bugfix
[x] Feature
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[ ] Documentation content changes
[ ] Other... Please describe:

How to Test

• Get the code

git clone https://github.com/bachuv/Durable-Task-Scheduler.git
cd Durable-Task-Scheduler
git checkout vabachu/java-entity-samples

• Test the code

Prerequisites: Docker, Java 11+, Maven, Azure Functions Core Tools v4

Start local services

docker run --name dtsemulator -d -p 8080:8080 -p 8082:8082 mcr.microsoft.com/dts/dts-emulator:latest
docker run --name azurite -d -p 10000:10000 -p 10001:10001 -p 10002:10002 mcr.microsoft.com/azure-storage/azurite

Test durable-task-sdks/java entities sample (Gradle)

cd samples/durable-task-sdks/java/entities
./gradlew runEntitiesPattern

Test durable-functions/java Entities sample (Maven)

cd samples/durable-functions/java/Entities
mvn clean package
mvn azure-functions:run
# In another terminal:
curl -X POST "http://localhost:7071/api/SignalCounter?key=test&op=add&value=7"
curl "http://localhost:7071/api/GetCounter?key=test"
curl -X POST "http://localhost:7071/api/StartCounterOrchestration?key=test-orch"

Test durable-functions/java HelloCities sample (Maven, verify no regression)

cd samples/durable-functions/java/HelloCities
mvn clean package
mvn azure-functions:run

In another terminal:

curl -X POST http://localhost:7071/api/StartChaining
curl -X POST http://localhost:7071/api/StartFanOutFanIn

What to Check

Verify that the following are valid

• SDK entities sample — ./gradlew runEntitiesPattern signals a counter entity directly, then runs 5 orchestrations that each produce final value: 12
• Functions entities sample — SignalCounter returns 202, GetCounter returns the correct counter value as JSON, StartCounterOrchestration completes with final value: 12
• Functions entities sample — SignalCounter?op=get returns 400 with a message pointing to GetCounter
• HelloCities no regression — mvn clean package then mvn azure-functions:run still works; StartChaining and StartFanOutFanIn return orchestration results
• READMEs — Run instructions in samples/durable-functions/java/README.md, HelloCities/README.md, and Entities/README.md match the actual commands needed

Other Information

• The azure-functions-maven-plugin package goal is now bound to the Maven package phase in both Java Functions samples, so the standard two-step flow (mvn clean package + mvn azure-functions:run) works out of the box — matching the Java Durable Functions quickstart.
• host.json storage provider type was changed from durabletask-scheduler to azureManaged in both HelloCities and Entities to match what the local Functions runtime recognizes.
• The SDK sample uses durabletask-client:1.9.0 and durabletask-azuremanaged:1.9.0; the Functions sample uses durabletask-azure-functions:1.9.0.
• Azurite is required locally because AzureWebJobsStorage=UseDevelopmentStorage=true in local.settings.json.