# javax.net.ssl.SSLException: closing inbound before receiving peer's close_notify

- **ID:** `java/ssl-exception-closed-ssl-socket`
- **Domain:** java
- **Category:** protocol_error
- **Verification:** ai_generated
- **Fix Rate:** 85%

## Root Cause

The SSL/TLS connection is being closed by the client or server without exchanging the proper close_notify alert, violating the TLS protocol specification.

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| Java 8 | active | — | — |
| Java 11 | active | — | — |
| Java 17 | active | — | — |
| Java 21 | active | — | — |

## Workarounds

1. **Add system property -Djdk.tls.acknowledgeCloseNotify=true to allow graceful handling of missing close_notify messages.** (85% success)
   ```
   Add system property -Djdk.tls.acknowledgeCloseNotify=true to allow graceful handling of missing close_notify messages.
   ```
2. **Ensure the server sends a proper close_notify alert before closing the socket. In Java, use SSLSocket.close() which automatically sends close_notify, not Socket.close().** (90% success)
   ```
   Ensure the server sends a proper close_notify alert before closing the socket. In Java, use SSLSocket.close() which automatically sends close_notify, not Socket.close().
   ```
3. **Catch the SSLException in the client code and treat it as a normal connection termination without retrying.** (75% success)
   ```
   Catch the SSLException in the client code and treat it as a normal connection termination without retrying.
   ```

## Dead Ends

- **Set javax.net.ssl.trustStore system property to a custom truststore** — This error is not related to truststore configuration; changing trust stores does not affect TLS close_notify handshake behavior. (90% fail)
- **Increase SSL socket timeout using setSoTimeout()** — Timeout settings do not control TLS shutdown behavior; the error occurs even with ample timeouts. (85% fail)
- **Disable SSL verification entirely with a custom TrustManager** — Disabling verification bypasses certificate checks but does not fix the protocol-level close_notify violation. (95% fail)