quickstarts/configuration/java/http/README.md

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# Dapr Configuration API
In this quickstart, you'll create a microservice which makes use of Dapr's Configuration API. Configuration items are key/value pairs containing configuration data such as app ids, partition keys, database names etc. The service gets configuration items from the configuration store and subscribes for configuration updates.
Visit [this](https://docs.dapr.io/developing-applications/building-blocks/configuration/) link for more information about Dapr and Configuration API.
> **Note:** This example leverages HTTP `requests` only. If you are looking for the example using the Dapr Client SDK (recommended) [click here](../sdk/).
This quickstart includes one service:
- Java service `order-processor`
## Prerequisites
- [Maven 3.x](https://maven.apache.org/install.html)
- Java JDK 11 (or greater):
- [Microsoft JDK 11](https://docs.microsoft.com/en-us/java/openjdk/download#openjdk-11)
- [Oracle JDK 11](https://www.oracle.com/technetwork/java/javase/downloads/index.html#JDK11)
- [OpenJDK 11](https://jdk.java.net/11/)
- Locally running redis instance - a redis instance is automatically created as a docker container when you run `dapr init`
- Install Redis CLI - [Getting started with Redis | Redis](https://redis.io/docs/getting-started/). `redis-cli` is installed as part of redis setup
## Add configuration items to the config store
- Open a new terminal and set values for config items `orderId1` and `orderId2` using `redis-cli`
<!-- STEP
name: Add configuration items
-->
```bash
redis-cli -n 0 MSET orderId1 "101" orderId2 "102"
```
<!-- END_STEP -->
## Build the Java file
<!-- STEP
name: Build Java file
-->
```bash
cd ./order-processor
mvn clean install
```
<!-- END_STEP -->
## Run order-processor
1. Navigate to `order-processor` directory.
2. Run the service app with Dapr.
<!-- STEP
name: Run order-processor service
expected_stdout_lines:
- '== APP == Configuration for orderId1:{"orderId1":{"value":"101"}}'
- '== APP == Configuration for orderId2:{"orderId2":{"value":"102"}}'
- '== APP == App subscribed to config changes with subscription id:'
- '= APP == App unsubscribed from config changes'
- '== APP == Shutting down spring app'
- "Exited App successfully"
expected_stderr_lines:
output_match_mode: substring
match_order: none
-->
```bash
cd ./order-processor
dapr run --app-id order-processor --app-port 6001 --components-path ../../../components -- java -jar target/OrderProcessingService-0.0.1-SNAPSHOT.jar
```
<!-- END_STEP -->
## (Optional) Update value of config items
1. Keep the `order-processor` app running and open a separate terminal
2. Change the values of `orderId1` and `orderId2` using `redis-cli`
3. `order-processor` app gets the updated values of config items
<!-- STEP
name: Update config items
-->
```bash
redis-cli -n 0 MSET orderId1 "103" orderId2 "104"
```
<!--END_STEP -->