Eliminate mutable field anti-patterns

[Akanksha-kedia]

Description

. ClusterStatsJdbcMonitor.java - Complete Immutable Configuration Refactor

Problem: Mutable Properties field causing potential thread safety issues Solution: Created comprehensive immutable configuration system

New Files Created:

• JdbcMonitorConfiguration.java - Immutable JDBC configuration class with factory methods

Key Changes:

• ✅ Replaced private final Properties properties with private final JdbcMonitorConfiguration jdbcConfig
• ✅ Added factory method JdbcMonitorConfiguration.from() for easy construction
• ✅ Added toProperties() method for backward compatibility with JDBC drivers
• ✅ Improved error handling with fail-fast validation
• ✅ Enhanced SSL configuration based on URL protocol
• ✅ Better resource management and exception handling

2. GatewayWebAppResource.java - Immutable UI Configuration

Problem: Mutable UIConfiguration field in web resource Solution: Created immutable wrapper with defensive copying

New Files Created:

• ImmutableUIConfiguration.java - Thread-safe UI configuration wrapper

Key Changes:

• ✅ Replaced private final UIConfiguration uiConfiguration with private final ImmutableUIConfiguration immutableUiConfiguration
• ✅ Added ImmutableUIConfiguration.copyOf() factory method
• ✅ Defensive copying in constructor to prevent external modification
• ✅ Maintained API compatibility while ensuring thread safety
• ✅ Used Guava's ImmutableList for collections

Additional context and related issues

Release notes

( ) This is not user-visible or is docs only, and no release notes are required.
( ) Release notes are required, with the following suggested text:

* Fix some things.

Summary by Sourcery

Eliminate mutable field anti-patterns by introducing immutable configuration handling in the JDBC monitor and web app resource to improve thread safety.

Enhancements:

• Replace mutable Properties field in ClusterStatsJdbcMonitor with a Guava ImmutableMap and construct a Properties copy at connection time
• Replace mutable UIConfiguration field in GatewayWebAppResource with an ImmutableUIConfiguration wrapper and perform defensive copying in the constructor
• Leverage Guava’s immutable collections to ensure thread-safe configuration usage

[sourcery-ai]

Hey there - I've reviewed your changes and they look great!

Prompt for AI Agents

Please address the comments from this code review:

## Individual Comments

### Comment 1
<location> `gateway-ha/src/main/java/io/trino/gateway/ha/clustermonitor/ClusterStatsJdbcMonitor.java:81-85` </location>
<code_context>
+            connectionProperties.putAll(properties);
             // automatically set ssl config based on url protocol
-            properties.setProperty("SSL", String.valueOf(parsedUrl.getProtocol().equals("https")));
+            connectionProperties.setProperty("SSL", String.valueOf(parsedUrl.getProtocol().equals("https")));
         }
         catch (MalformedURLException e) {
</code_context>

<issue_to_address>
**suggestion:** Overwriting SSL property may cause confusion if initial value differs.

Since the SSL property is set both from the initial properties and then overwritten based on the URL protocol, clarify which value should take precedence, or remove the initial assignment if it is always replaced.

```suggestion
            // Create connection properties from immutable map
            connectionProperties = new Properties();
            // Remove any existing SSL property to avoid confusion
            Properties filteredProperties = new Properties();
            for (String key : properties.stringPropertyNames()) {
                if (!key.equalsIgnoreCase("SSL")) {
                    filteredProperties.setProperty(key, properties.getProperty(key));
                }
            }
            connectionProperties.putAll(filteredProperties);
            // Set SSL config based on url protocol, always taking precedence
            connectionProperties.setProperty("SSL", String.valueOf(parsedUrl.getProtocol().equals("https")));
```
</issue_to_address>

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[Akanksha-kedia]

@ebyhr @mosabua @oneonestar please review.

[oneonestar]

We should also remove BackendStateConfiguration.ssl since it's value is always being replaced by the url protocol.

[Akanksha-kedia]

@oneonestar please review

[oneonestar]

Since properties will not have "SSL" anymore, we don't need this logic.

[github-actions]

This pull request has gone a while without any activity. Ask for help on #trino-gateway-dev on Trino slack.