JavaSteam

JavaSteam is a Java port of SteamKit2 that targets Java 17. To use it in your project, add the Maven Central repository and the in.dragonbra:javasteam dependency.

1. Add the repository

Gradle:

repositories {
    mavenCentral()
}

Maven:

<repository>
    <id>central</id>
    <url>https://repo.maven.apache.org/maven2</url>
</repository>

2. Add the dependency

Gradle:

implementation 'in.dragonbra:javasteam:x.y.z'

Maven:

<dependency>
    <groupId>in.dragonbra</groupId>
    <artifactId>javasteam</artifactId>
    <version>x.y.z</version>
</dependency>

JavaSteam requires a cryptography dependency to function. You must choose the one appropriate for your platform:

• Android (Deprecated): Use Spongy Castle.
• Android and Non-Android: Use Bouncy Castle (bcprov-jdk18on).

Troubleshooting InvalidKeyException If you encounter java.security.InvalidKeyException: Illegal key size or default parameters during message encryption, you may need to install the Unlimited Strength Jurisdiction Policy Files into your ${java.home}/jre/lib/security/ directory.

For practical implementation guidance, refer to the following resources:

• Getting Started Guide: Detailed walkthroughs available on the official wiki.
• Code Samples: View the javasteam-samples directory for implementation examples.
• Open Source Projects: Explore existing projects using JavaSteam for real-world context.

If you are developing or building the project from the repository, use the following Gradle commands:

Full build:

./gradlew build -x signMavenJavaPublication

Generate required classes (Protobufs and Steam language):

./gradlew generateProto generateSteamLanguage generateProjectVersion

The Client class is the primary interface for downloading game content from Steam content delivery networks (CDNs). It requires an associated, connected, and logged-in SteamClient instance.

Key capabilities include:

• Downloading depot manifests (downloadManifest).
• Downloading depot chunks (downloadDepotChunk).
• Supporting proxy servers and CDN authentication tokens.
• Decrypting filenames and processing chunks if a depotKey is provided.

Note: The Client implements Closeable. You should call .close() to cancel pending coroutines and shut down the underlying HTTP client's connection pool and executor service.

// Example initialization (requires an existing SteamClient)
val cdnClient = Client(steamClient)

try {
    // Perform downloads...
} finally {
    cdnClient.close()
}

Depending on your use case, you may need to add the following optional dependencies:

Protobufs

If you intend to work with protobuf builders directly (for actions not supported by a handler), add protobuf-java. It is recommended to match the version used by JavaSteam to avoid errors or warnings.

Content Downloading

To support content downloading, add these dependencies:

• XZ For Java
• ZSTD JNI (Note: For Android, use the aar library type).

You can find the specific versions supported by the current JavaSteam release in the libs.versions.toml file.

Once a ServerRecord is created, you can access the connection details through the following properties:

• host: Returns the hostname or IP address as a String.
• port: Returns the port number as an Int.
• endpoint: Returns the underlying InetSocketAddress used for the connection.
• protocolTypes: Returns an EnumSet of the ProtocolTypes supported by this server.

The Server class represents a single Steam3 'Steampipe' content server. You can instantiate a Server using two static factory methods provided in its companion object:

1. fromInetSocketAddress(endPoint: InetSocketAddress): Creates a server from a network socket address. It automatically determines if the protocol is HTTPS or HTTP based on whether the port is 443.
2. fromHostAndPort(hostname: String, port: Int): Creates a server from a hostname string and an integer port. It also automatically sets the protocol to HTTPS if the port is 443.

Note that host and vHost are both initialized to the provided hostname/address.

// Using hostname and port
val server = Server.fromHostAndPort("cdn.steampowered.com", 443)

// Using InetSocketAddress
val address = InetSocketAddress("127.0.0.1", 80)
val serverFromAddress = Server.fromInetSocketAddress(address)

The Client.buildCommand companion method constructs a valid HttpUrl for CDN requests, supporting proxy transformations.

Parameters:

• server: The target Server.
• command: The request path (e.g., depot/123/manifest/456).
• query (optional): A query string (e.g., ?token=abc).
• proxyServer (optional): A Server instance. If proxyServer.useAsProxy is true and proxyServer.proxyRequestPathTemplate is provided, the URL is constructed using the template (replacing %host% and %path%).

Returns: A configured HttpUrl object.