Add JVM SOCKS5 proxy support to NettyConnectionClient

[zrlw]

What is the purpose of the change?

try to fix #16276

Checklist

• Make sure there is a GitHub_issue field for the change.
• Write a pull request description that is detailed enough to understand what the pull request does, how, and why.
• Write necessary unit-test to verify your logic correction. If the new feature or significant change is committed, please remember to add sample in dubbo samples project.
• Make sure gitHub actions can pass. Why the workflow is failing and how to fix it?

[codecov-commenter]

Codecov Report

❌ Patch coverage is 95.00000% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 60.81%. Comparing base (c3ceb27) to head (59c4488).

Files with missing lines	Patch %	Lines
...e/dubbo/remoting/transport/netty4/NettyClient.java	93.33%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##                3.3   #16285      +/-   ##
============================================
+ Coverage     60.79%   60.81%   +0.01%     
+ Complexity    11777    11775       -2     
============================================
  Files          1953     1953              
  Lines         89208    89214       +6     
  Branches      13458    13458              
============================================
+ Hits          54234    54254      +20     
+ Misses        29403    29395       -8     
+ Partials       5571     5565       -6     

Flag	Coverage Δ
integration-tests-java21	32.17% <65.00%> (+0.04%)	⬆️
integration-tests-java8	32.23% <65.00%> (-0.09%)	⬇️
samples-tests-java21	32.21% <65.00%> (+0.08%)	⬆️
samples-tests-java8	29.86% <65.00%> (+<0.01%)	⬆️
unit-tests-java11	59.07% <95.00%> (+0.04%)	⬆️
unit-tests-java17	58.50% <95.00%> (-0.02%)	⬇️
unit-tests-java21	58.53% <95.00%> (+0.02%)	⬆️
unit-tests-java25	58.49% <95.00%> (+0.01%)	⬆️
unit-tests-java8	59.07% <95.00%> (+<0.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[Copilot]

Pull request overview

This PR adds SOCKS5 proxy support to the tri/HTTP2 Netty client path by wiring Netty’s Socks5ProxyHandler into NettyConnectionClient when JVM-style proxy properties are present, addressing #16276.

Changes:

• Read socksProxyHost / socksProxyPort from Dubbo’s global configuration (incl. system properties) and conditionally add Socks5ProxyHandler to the Netty pipeline.
• Skip proxying for local/loopback targets via a new isFilteredAddress(...) helper.
• Add supporting imports/constants for the new behavior.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[RainYuY]

@zrlw Let's handle the Copilot prompt first, either reject or accept is fine

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 2 comments.

[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

Comments suppressed due to low confidence (1)

dubbo-remoting/dubbo-remoting-netty4/src/main/java/org/apache/dubbo/remoting/transport/netty4/NettyConnectionClient.java:63

• NettyClient.SOCKS_PROXY_HOST/PORT/DEFAULT_SOCKS_PROXY_PORT are declared private in NettyClient, so referencing them here will not compile. Define these keys locally (or make them accessible via a public/package-private constant in another change).

public final class NettyConnectionClient extends AbstractNettyConnectionClient {

    private Bootstrap bootstrap;

[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 3 comments.

[Copilot]

Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated 3 comments.