utility-components

Tool Components

Applicable Scenarios

• Using JWT or authentication-related tools
• Parsing variable expressions, conditional expressions, or custom functions
• Using thread pools, batch processing, or loop retry tools
• Implementing or reusing chain of responsibility pattern components

Inapplicable Scenarios

• It is only a framework-level cross-cutting practice, such as AOP, distributed locks, monitoring, or auditing
• It is only inter-service communication, event-driven, or multi-environment configuration
• It is only a data structure or process of a certain business module itself

Quick Guidance

1. This skill focuses on "how to use specific tools", not "how to implement framework practices".
2. If the question is more like "is there an existing component that can be directly reused", it usually falls here.
3. First enter the corresponding reference document by topic:
   • JWT：reference/1-jwt-security.md
   • Expression parsing:reference/2-expression-parser.md
   • Thread pools and loop tools:reference/3-thread-pool-loop-util.md
   • Chain of responsibility:reference/4-chain-responsibility.md
4. If what you want to solve is a cross-cutting architecture problem, switch to common-technical-practices; if what you want to solve is a microservice foundation problem, switch to microservice-infrastructure。

High-Signal Rules

• This is more about "component-level reuse", not "platform-level framework solutions"
• Tool components should prioritize reusing existing implementations rather than reinventing the wheel
• The chain of responsibility here is more about specific components and implementations, not a pattern encyclopedia
• Before using a component, first confirm whether it solves a business problem or just makes the code look more complex

Key Pitfalls

• Mixing up component issues and framework practice issues
• Rebuilding a new set even though ready-made tools already exist
• Only knowing how to call utility classes, without understanding inputs, outputs, and boundary conditions
• Overusing the chain of responsibility, thread pools, and expression parsing where they are not needed

Further Reading

• JWT：reference/1-jwt-security.md
• Expression parsing:reference/2-expression-parser.md
• Thread pools and loop tools:reference/3-thread-pool-loop-util.md
• Chain of responsibility:reference/4-chain-responsibility.md
• If you need cross-cutting practices: see also common-technical-practices
• If you need a microservice foundation: see also microservice-infrastructure