[Bug] Potential NPE in DefaultHAConnection and AutoSwitchHAConnection when getRemoteSocketAddress() returns null

[daguimu]

Before Creating the Bug Report

• I found a bug, not just asking a question, which should be created in GitHub Discussions.
• I have searched the GitHub Issues and GitHub Discussions of this repository and believe that this is not a duplicate.
• I have confirmed that this bug belongs to the current repository, not other repositories of RocketMQ.

Runtime platform environment

All platforms

RocketMQ version

develop branch (latest)

JDK Version

All

Describe the Bug

In DefaultHAConnection (line 64) and AutoSwitchHAConnection (line 109), .toString() is called directly on the return value of getRemoteSocketAddress() without a null check:

this.clientAddress = this.socketChannel.socket().getRemoteSocketAddress().toString();

According to the Java documentation, Socket.getRemoteSocketAddress() returns null if the socket is not connected. In edge cases (e.g., the socket is accepted but the remote peer disconnects before the HA connection constructor completes), this can throw a NullPointerException, which would crash the HA connection setup.

Steps to Reproduce

1. Under network instability, a slave connects and immediately disconnects
2. The master accepts the socket channel
3. DefaultHAConnection constructor is called
4. getRemoteSocketAddress() returns null because the peer has already disconnected
5. .toString() on null throws NPE

What Did You Expect to See?

The HA connection should handle null remote address gracefully.

What Did You See Instead?

NullPointerException in the HA connection constructor.

Additional Context

Affected files:

• store/src/main/java/org/apache/rocketmq/store/ha/DefaultHAConnection.java:64
• store/src/main/java/org/apache/rocketmq/store/ha/autoswitch/AutoSwitchHAConnection.java:109