Properties

Properties

The Dapr Java SDK provides a set of global properties that control the behavior of the SDK. These properties can be configured using environment variables or system properties. System properties can be set using the -D flag when running your Java application.

These properties affect the entire SDK, including clients and runtime. They control aspects such as:

• Sidecar connectivity (endpoints, ports)
• Security settings (TLS, API tokens)
• Performance tuning (timeouts, connection pools)
• Protocol settings (gRPC, HTTP)
• String encoding

Environment Variables

The following environment variables are available for configuring the Dapr Java SDK:

Sidecar Endpoints

When these variables are set, the client will automatically use them to connect to the Dapr sidecar.

API Token

gRPC Configuration

TLS Settings

For secure gRPC communication, you can configure TLS settings using the following environment variables:

Keepalive Settings

Configure gRPC keepalive behavior using these environment variables:

Inbound Message Settings

Configure gRPC inbound message settings using these environment variables:

HTTP Client Configuration

These properties control the behavior of the HTTP client used for communication with the Dapr sidecar:

API Configuration

These properties control the behavior of API calls made through the SDK:

String Encoding

System Properties

All environment variables can be set as system properties using the -D flag. Here is the complete list of available system properties:

Property Resolution Order

Properties are resolved in the following order:

1. Override values (if provided when creating a Properties instance)
2. System properties (set via -D)
3. Environment variables
4. Default values

The SDK checks each source in order. If a value is invalid for the property type (e.g., non-numeric for a numeric property), the SDK will log a warning and try the next source. For example:

# Invalid boolean value - will be ignored
java -Ddapr.grpc.enable.keep.alive=not-a-boolean -jar myapp.jar

# Valid boolean value - will be used
export DAPR_GRPC_ENABLE_KEEP_ALIVE=false

In this case, the environment variable is used because the system property value is invalid. However, if both values are valid, the system property takes precedence:

# Valid boolean value - will be used
java -Ddapr.grpc.enable.keep.alive=true -jar myapp.jar

# Valid boolean value - will be ignored
export DAPR_GRPC_ENABLE_KEEP_ALIVE=false

Override values can be set using the DaprClientBuilder in two ways:

1. Using individual property overrides (recommended for most cases):

import io.dapr.config.Properties;

// Set a single property override
DaprClient client = new DaprClientBuilder()
    .withPropertyOverride(Properties.GRPC_ENABLE_KEEP_ALIVE, "true")
    .build();

// Or set multiple property overrides
DaprClient client = new DaprClientBuilder()
    .withPropertyOverride(Properties.GRPC_ENABLE_KEEP_ALIVE, "true")
    .withPropertyOverride(Properties.HTTP_CLIENT_READ_TIMEOUT_SECONDS, "120")
    .build();

2. Using a Properties instance (useful when you have many properties to set at once):

// Create a map of property overrides
Map<String, String> overrides = new HashMap<>();
overrides.put("dapr.grpc.enable.keep.alive", "true");
overrides.put("dapr.http.client.readTimeoutSeconds", "120");

// Create a Properties instance with overrides
Properties properties = new Properties(overrides);

// Use these properties when creating a client
DaprClient client = new DaprClientBuilder()
    .withProperties(properties)
    .build();

For most use cases, you’ll use system properties or environment variables. Override values are primarily used when you need different property values for different instances of the SDK in the same application.

Proxy Configuration

You can configure proxy settings for your Java application using system properties. These are standard Java system properties that are part of Java’s networking layer (java.net package), not specific to Dapr. They are used by Java’s networking stack, including the HTTP client that Dapr’s SDK uses.

For detailed information about Java’s proxy configuration, including all available properties and their usage, see the Java Networking Properties documentation.

For example, here’s how to configure a proxy:

# Configure HTTP proxy - replace with your actual proxy server details
java -Dhttp.proxyHost=your-proxy-server.com -Dhttp.proxyPort=8080 -jar myapp.jar

# Configure HTTPS proxy - replace with your actual proxy server details
java -Dhttps.proxyHost=your-proxy-server.com -Dhttps.proxyPort=8443 -jar myapp.jar

Replace your-proxy-server.com with your actual proxy server hostname or IP address, and adjust the port numbers to match your proxy server configuration.

These proxy settings will affect all HTTP/HTTPS connections made by your Java application, including connections to the Dapr sidecar.