azure-appconfiguration-java

Author's original introduction

Azure App Configuration SDK for Java. Centralized application configuration management with key-value settings, feature flags, and snapshots. Triggers: "ConfigurationClient java", "app configuration java", "feature flag java", "configuration setting java", "azure config java".

SkillPi interpretation

Tasks

azure-appconfiguration-java

Audience

Use the scope in the original author introduction.

Inputs and outputs

See the complete source; users must confirm cloud data transfers.

Software, accounts and paid services

This azure-appconfiguration-java package contains Microsoft Azure SDK documentation and examples, not a runtime-verified installer. Check SDK names/versions, tenant/subscription and actual endpoints; grant only task-specific least privilege. Never put administrator credentials or real secrets in samples, logs or commits. Connected cloud services may receive selected text, documents, audio, messages, logs or other input and incur charges; confirm scope, redaction and costs first. Ask the user to confirm each resource creation/update/deletion, key/access change or outbound message and test with disposable resources before production. Replace and verify placeholder endpoints and samples. SkillPi checked pinned source, complete attachments and static/antivirus evidence only; it did not run the SDK, verify service compatibility or authorize cloud access.

Limits and differences

Original author introduction preserved; Chinese is a corresponding translation. Examples were not run by SkillPi; versions, compatibility and outcomes are author claims.

Testing

Not tested

Security rating and access scope

caution · Static evidence review; not a runtime safety guarantee.

This azure-appconfiguration-java package contains Microsoft Azure SDK documentation and examples, not a runtime-verified installer. Check SDK names/versions, tenant/subscription and actual endpoints; grant only task-specific least privilege. Never put administrator credentials or real secrets in samples, logs or commits. Connected cloud services may receive selected text, documents, audio, messages, logs or other input and incur charges; confirm scope, redaction and costs first. Ask the user to confirm each resource creation/update/deletion, key/access change or outbound message and test with disposable resources before production. Replace and verify placeholder endpoints and samples. SkillPi checked pinned source, complete attachments and static/antivirus evidence only; it did not run the SDK, verify service compatibility or authorize cloud access.

Before use, confirm and authorize actual file access, external services and network destinations in your host. This review grants no runtime permissions.

Original SKILL.md

---
name: azure-appconfiguration-java
description: |
  Azure App Configuration SDK for Java. Centralized application configuration management with key-value settings, feature flags, and snapshots.
  Triggers: "ConfigurationClient java", "app configuration java", "feature flag java", "configuration setting java", "azure config java".
license: MIT
metadata:
  author: Microsoft
  version: "1.0.0"
  package: com.azure:azure-data-appconfiguration
---

# Azure App Configuration SDK for Java

Client library for Azure App Configuration, a managed service for centralizing application configurations.

## Installation

```xml
<dependency>
    <groupId>com.azure</groupId>
    <artifactId>azure-data-appconfiguration</artifactId>
    <version>1.8.0</version>
</dependency>
```

Or use Azure SDK BOM:

```xml
<dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>com.azure</groupId>
            <artifactId>azure-sdk-bom</artifactId>
            <version>{bom_version}</version>
            <type>pom</type>
            <scope>import</scope>
        </dependency>
    </dependencies>
</dependencyManagement>

<dependencies>
    <dependency>
        <groupId>com.azure</groupId>
        <artifactId>azure-data-appconfiguration</artifactId>
    </dependency>
</dependencies>
```

## Prerequisites

- Azure App Configuration store
- Connection string or Entra ID credentials

## Environment Variables

```bash
AZURE_APPCONFIG_CONNECTION_STRING=Endpoint=https://<store>.azconfig.io;Id=<id>;Secret=<secret>  # Alternative to Entra ID auth
AZURE_APPCONFIG_ENDPOINT=https://<store>.azconfig.io  # Required for all auth methods
AZURE_TOKEN_CREDENTIALS=prod  # Required only if DefaultAzureCredential is used in production
```

## Client Creation

### With Connection String

```java
import com.azure.data.appconfiguration.ConfigurationClient;
import com.azure.data.appconfiguration.ConfigurationClientBuilder;

ConfigurationClient configClient = new ConfigurationClientBuilder()
    .connectionString(System.getenv("AZURE_APPCONFIG_CONNECTION_STRING"))
    .buildClient();
```

### Async Client

```java
import com.azure.data.appconfiguration.ConfigurationAsyncClient;

ConfigurationAsyncClient asyncClient = new ConfigurationClientBuilder()
    .connectionString(connectionString)
    .buildAsyncClient();
```

### With Entra ID (Recommended)

```java
import com.azure.core.credential.TokenCredential;
import com.azure.identity.AzureIdentityEnvVars;
import com.azure.identity.DefaultAzureCredentialBuilder;
import com.azure.identity.ManagedIdentityCredentialBuilder;

// Local dev: DefaultAzureCredential. Production: set AZURE_TOKEN_CREDENTIALS=prod or AZURE_TOKEN_CREDENTIALS=<specific_credential>
TokenCredential credential = new DefaultAzureCredentialBuilder()
    .requireEnvVars(AzureIdentityEnvVars.AZURE_TOKEN_CREDENTIALS)
    .build();
// Or use a specific credential directly in production:
// See https://learn.microsoft.com/java/api/overview/azure/identity-readme?view=azure-java-stable#credential-classes
// TokenCredential credential = new ManagedIdentityCredentialBuilder().build();

ConfigurationClient configClient = new ConfigurationClientBuilder()
    .credential(credential)
    .endpoint(System.getenv("AZURE_APPCONFIG_ENDPOINT"))
    .buildClient();
```

## Key Concepts

| Concept | Description |
|---------|-------------|
| Configuration Setting | Key-value pair with optional label |
| Label | Dimension for separating settings (e.g., environments) |
| Feature Flag | Special setting for feature management |
| Secret Reference | Setting pointing to Key Vault secret |
| Snapshot | Point-in-time immutable view of settings |

## Configuration Setting Operations

### Create Setting (Add)

Creates only if setting doesn't exist:

```java
import com.azure.data.appconfiguration.models.ConfigurationSetting;

ConfigurationSetting setting = configClient.addConfigurationSetting(
    "app/database/connection", 
    "Production", 
    "Server=prod.db.com;Database=myapp"
);
```

### Create or Update Setting (Set)

Creates or overwrites:

```java
ConfigurationSetting setting = configClient.setConfigurationSetting(
    "app/cache/enabled", 
    "Production", 
    "true"
);
```

### Get Setting

```java
ConfigurationSetting setting = configClient.getConfigurationSetting(
    "app/database/connection", 
    "Production"
);
System.out.println("Value: " + setting.getValue());
System.out.println("Content-Type: " + setting.getContentType());
System.out.println("Last Modified: " + setting.getLastModified());
```

### Conditional Get (If Changed)

```java
import com.azure.core.http.rest.Response;
import com.azure.core.util.Context;

Response<ConfigurationSetting> response = configClient.getConfigurationSettingWithResponse(
    setting,      // Setting with ETag
    null,         // Accept datetime
    true,         // ifChanged - only fetch if modified
    Context.NONE
);

if (response.getStatusCode() == 304) {
    System.out.println("Setting not modified");
} else {
    ConfigurationSetting updated = response.getValue();
}
```

### Update Setting

```java
ConfigurationSetting updated = configClient.setConfigurationSetting(
    "app/cache/enabled", 
    "Production", 
    "false"
);
```

### Conditional Update (If Unchanged)

```java
// Only update if ETag matches (no concurrent modifications)
Response<ConfigurationSetting> response = configClient.setConfigurationSettingWithResponse(
    setting,     // Setting with current ETag
    true,        // ifUnchanged
    Context.NONE
);
```

### Delete Setting

```java
ConfigurationSetting deleted = configClient.deleteConfigurationSetting(
    "app/cache/enabled", 
    "Production"
);
```

### Conditional Delete

```java
Response<ConfigurationSetting> response = configClient.deleteConfigurationSettingWithResponse(
    setting,     // Setting with ETag
    true,        // ifUnchanged
    Context.NONE
);
```

## List and Filter Settings

### List by Key Pattern

```java
import com.azure.data.appconfiguration.models.SettingSelector;
import com.azure.core.http.rest.PagedIterable;

SettingSelector selector = new SettingSelector()
    .setKeyFilter("app/*");

PagedIterable<ConfigurationSetting> settings = configClient.listConfigurationSettings(selector);
for (ConfigurationSetting s : settings) {
    System.out.println(s.getKey() + " = " + s.getValue());
}
```

### List by Label

```java
SettingSelector selector = new SettingSelector()
    .setKeyFilter("*")
    .setLabelFilter("Production");

PagedIterable<ConfigurationSetting> settings = configClient.listConfigurationSettings(selector);
```

### List by Multiple Keys

```java
SettingSelector selector = new SettingSelector()
    .setKeyFilter("app/database/*,app/cache/*");

PagedIterable<ConfigurationSetting> settings = configClient.listConfigurationSettings(selector);
```

### List Revisions

```java
SettingSelector selector = new SettingSelector()
    .setKeyFilter("app/database/connection");

PagedIterable<ConfigurationSetting> revisions = configClient.listRevisions(selector);
for (ConfigurationSetting revision : revisions) {
    System.out.println("Value: " + revision.getValue() + ", Modified: " + revision.getLastModified());
}
```

## Feature Flags

### Create Feature Flag

```java
import com.azure.data.appconfiguration.models.FeatureFlagConfigurationSetting;
import com.azure.data.appconfiguration.models.FeatureFlagFilter;
import java.util.Arrays;

FeatureFlagFilter percentageFilter = new FeatureFlagFilter("Microsoft.Percentage")
    .addParameter("Value", 50);

FeatureFlagConfigurationSetting featureFlag = new FeatureFlagConfigurationSetting("beta-feature", true)
    .setDescription("Beta feature rollout")
    .setClientFilters(Arrays.asList(percentageFilter));

FeatureFlagConfigurationSetting created = (FeatureFlagConfigurationSetting)
    configClient.addConfigurationSetting(featureFlag);
```

### Get Feature Flag

```java
FeatureFlagConfigurationSetting flag = (FeatureFlagConfigurationSetting)
    configClient.getConfigurationSetting(featureFlag);

System.out.println("Feature: " + flag.getFeatureId());
System.out.println("Enabled: " + flag.isEnabled());
System.out.println("Filters: " + flag.getClientFilters());
```

### Update Feature Flag

```java
featureFlag.setEnabled(false);
FeatureFlagConfigurationSetting updated = (FeatureFlagConfigurationSetting)
    configClient.setConfigurationSetting(featureFlag);
```

## Secret References

### Create Secret Reference

```java
import com.azure.data.appconfiguration.models.SecretReferenceConfigurationSetting;

SecretReferenceConfigurationSetting secretRef = new SecretReferenceConfigurationSetting(
    "app/secrets/api-key",
    "https://myvault.vault.azure.net/secrets/api-key"
);

SecretReferenceConfigurationSetting created = (SecretReferenceConfigurationSetting)
    configClient.addConfigurationSetting(secretRef);
```

### Get Secret Reference

```java
SecretReferenceConfigurationSetting ref = (SecretReferenceConfigurationSetting)
    configClient.getConfigurationSetting(secretRef);

System.out.println("Secret URI: " + ref.getSecretId());
```

## Read-Only Settings

### Set Read-Only

```java
ConfigurationSetting readOnly = configClient.setReadOnly(
    "app/critical/setting", 
    "Production", 
    true
);
```

### Clear Read-Only

```java
ConfigurationSetting writable = configClient.setReadOnly(
    "app/critical/setting", 
    "Production", 
    false
);
```

## Snapshots

### Create Snapshot

```java
import com.azure.data.appconfiguration.models.ConfigurationSnapshot;
import com.azure.data.appconfiguration.models.ConfigurationSettingsFilter;
import com.azure.core.util.polling.SyncPoller;
import com.azure.core.util.polling.PollOperationDetails;

List<ConfigurationSettingsFilter> filters = new ArrayList<>();
filters.add(new ConfigurationSettingsFilter("app/*"));

SyncPoller<PollOperationDetails, ConfigurationSnapshot> poller = configClient.beginCreateSnapshot(
    "release-v1.0",
    new ConfigurationSnapshot(filters),
    Context.NONE
);
poller.setPollInterval(Duration.ofSeconds(10));
poller.waitForCompletion();

ConfigurationSnapshot snapshot = poller.getFinalResult();
System.out.println("Snapshot: " + snapshot.getName() + ", Status: " + snapshot.getStatus());
```

### Get Snapshot

```java
ConfigurationSnapshot snapshot = configClient.getSnapshot("release-v1.0");
System.out.println("Created: " + snapshot.getCreatedAt());
System.out.println("Items: " + snapshot.getItemCount());
```

### List Settings in Snapshot

```java
PagedIterable<ConfigurationSetting> settings = 
    configClient.listConfigurationSettingsForSnapshot("release-v1.0");

for (ConfigurationSetting setting : settings) {
    System.out.println(setting.getKey() + " = " + setting.getValue());
}
```

### Archive Snapshot

```java
ConfigurationSnapshot archived = configClient.archiveSnapshot("release-v1.0");
System.out.println("Status: " + archived.getStatus()); // archived
```

### Recover Snapshot

```java
ConfigurationSnapshot recovered = configClient.recoverSnapshot("release-v1.0");
System.out.println("Status: " + recovered.getStatus()); // ready
```

### List All Snapshots

```java
import com.azure.data.appconfiguration.models.SnapshotSelector;

SnapshotSelector selector = new SnapshotSelector().setNameFilter("release-*");
PagedIterable<ConfigurationSnapshot> snapshots = configClient.listSnapshots(selector);

for (ConfigurationSnapshot snap : snapshots) {
    System.out.println(snap.getName() + " - " + snap.getStatus());
}
```

## Labels

### List Labels

```java
import com.azure.data.appconfiguration.models.SettingLabelSelector;

configClient.listLabels(new SettingLabelSelector().setNameFilter("*"))
    .forEach(label -> System.out.println("Label: " + label.getName()));
```

## Async Operations

```java
ConfigurationAsyncClient asyncClient = new ConfigurationClientBuilder()
    .connectionString(connectionString)
    .buildAsyncClient();

// Async list with reactive streams
asyncClient.listConfigurationSettings(new SettingSelector().setLabelFilter("Production"))
    .subscribe(
        setting -> System.out.println(setting.getKey() + " = " + setting.getValue()),
        error -> System.err.println("Error: " + error.getMessage()),
        () -> System.out.println("Completed")
    );
```

## Error Handling

```java
import com.azure.core.exception.HttpResponseException;

try {
    configClient.getConfigurationSetting("nonexistent", null);
} catch (HttpResponseException e) {
    if (e.getResponse().getStatusCode() == 404) {
        System.err.println("Setting not found");
    } else {
        System.err.println("Error: " + e.getMessage());
    }
}
```

## Best Practices

1. **Use labels** — Separate configurations by environment (Dev, Staging, Production)
2. **Use snapshots** — Create immutable snapshots for releases
3. **Feature flags** — Use for gradual rollouts and A/B testing
4. **Secret references** — Store sensitive values in Key Vault
5. **Conditional requests** — Use ETags for optimistic concurrency
6. **Read-only protection** — Lock critical production settings
7. **Use Entra ID** — Preferred over connection strings
8. **Async client** — Use for high-throughput scenarios

## Reference Links

| Resource | URL |
|----------|-----|
| Maven Package | https://central.sonatype.com/artifact/com.azure/azure-data-appconfiguration |
| GitHub | https://github.com/Azure/azure-sdk-for-java/tree/main/sdk/appconfiguration/azure-data-appconfiguration |
| API Documentation | https://aka.ms/java-docs |
| Product Docs | https://learn.microsoft.com/azure/azure-app-configuration |
| Samples | https://github.com/Azure/azure-sdk-for-java/tree/main/sdk/appconfiguration/azure-data-appconfiguration/src/samples |
| Troubleshooting | https://github.com/Azure/azure-sdk-for-java/blob/main/sdk/appconfiguration/azure-data-appconfiguration/TROUBLESHOOTING.md |

Copyright and license notice

    MIT License

    Copyright (c) Microsoft Corporation.

    Permission is hereby granted, free of charge, to any person obtaining a copy
    of this software and associated documentation files (the "Software"), to deal
    in the Software without restriction, including without limitation the rights
    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
    copies of the Software, and to permit persons to whom the Software is
    furnished to do so, subject to the following conditions:

    The above copyright notice and this permission notice shall be included in all
    copies or substantial portions of the Software.

    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
    SOFTWARE