grpc/grpc-java · error · UnsupportedOperationException

getInetAddress() not supported

Error message

getInetAddress() not supported

What it means

UdsSocket emulates java.net.Socket over an Android LocalSocket. A LocalSocket has no java.net.InetAddress — it is addressed by a filesystem path or abstract namespace, not an IP address — so getInetAddress() is implemented to throw UnsupportedOperationException instead of returning a meaningless value.

Source

Thrown at android/src/main/java/io/grpc/android/UdsSocket.java:98

  @Override
  public void connect(SocketAddress endpoint) throws IOException {
    localSocket.connect(localSocketAddress);
  }

  @Override
  public void connect(SocketAddress endpoint, int timeout) throws IOException {
    localSocket.connect(localSocketAddress, timeout);
  }

  @Override
  public SocketChannel getChannel() {
    throw new UnsupportedOperationException("getChannel() not supported");
  }

  @Override
  public InetAddress getInetAddress() {
    throw new UnsupportedOperationException("getInetAddress() not supported");
  }

  @Override
  public InputStream getInputStream() throws IOException {
    return new FilterInputStream(localSocket.getInputStream()) {
      @Override
      public void close() throws IOException {
        UdsSocket.this.close();
      }
    };
  }

  @Override
  public boolean getKeepAlive() {
    throw new UnsupportedOperationException("Unsupported operation getKeepAlive()");
  }

  @Override

View on GitHub (pinned to 64daddc1f3)

Solutions

1. Do not query IP-level metadata on UDS sockets; use the UDS path passed to UdsChannelBuilder.forPath() as the identity instead.
2. Guard address-dependent code with a check for UdsSocket (or catch UnsupportedOperationException) and fall back to the configured path.
3. If IP-level addressing is required, use a TCP channel rather than the UDS transport.

Example fix

// before
InetAddress addr = socket.getInetAddress();
// after
String peer = "uds:" + udsPath; // identity for UDS sockets
InetAddress addr = socket.getClass().getSimpleName().equals("UdsSocket") ? null : socket.getInetAddress();

static boolean isUdsSocket(Socket s) {
  return s.getClass().getName().equals("io.grpc.android.UdsSocket");
}

try {
  InetAddress addr = socket.getInetAddress();
} catch (UnsupportedOperationException e) {
  String peerId = "uds:" + configuredPath; // use the UDS path as identity
}

When it happens

Trigger: Calling getInetAddress() on the UdsSocket produced by UdsSocketFactory, e.g. logging code, security checks, or libraries that record the remote IP of a connected socket.

Common situations: Network monitoring/logging frameworks capturing peer addresses; retry or policy logic keyed on the remote IP; tests asserting socket metadata.

Understand the failure class

Background: UnsupportedOperationException and "is not supported" errors: when a library deliberately refuses a call — this error's family across 30 libraries.

Related errors

• getChannel() not supported
• Unsupported operation getLocalAddress()
• Unsupported operation getLocalPort()
• Unsupported operation getKeepAlive()
• Unsupported operation getOOBInline()

AI-assisted analysis of grpc/grpc-java@64daddc1f3 (2026-09-08). Data as JSON: /api/errors/342b25447bc518dd. Report an issue: GitHub.