Interface ExpressionEvaluator

Functional Interface:
This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.
@FunctionalInterface public interface ExpressionEvaluator
Expression-evaluation SPI (optional). 表达式求值 SPI（可选）。

The engine calls this SPI to evaluate ${expr} placeholders found in DSL fields (e.g. transition when guards, assignee values). Implementations are typically thin adapters over SpEL, MVEL, OGNL, Aviator, etc.

引擎在求值 DSL 中的 ${expr} 占位符（如 transition 的 when 守卫、assignee 取值等）时调用本 SPI。实现通常是 SpEL / MVEL / OGNL / Aviator 等表达式引擎的薄适配。

Security requirement (/sec P1, MANDATORY): implementations MUST use a sandboxed evaluation environment:

  • SpEL implementations MUST use SimpleEvaluationContext; StandardEvaluationContext is forbidden.
  • Type references T(...), constructor invocations new, and reflective access such as #this.class MUST be disabled.
  • When the DSL source is untrusted (e.g. form-based import) the implementation SHOULD further restrict accessible root-object fields.

安全要求（/sec P1，强制）：实现方必须使用受限的求值环境：

  • SpEL 实现必须使用 SimpleEvaluationContext，禁用 StandardEvaluationContext。
  • 禁止类型引用 T(...)、构造函数 new、反射 #this.class。
  • 当 DSL 来源不可信时（如表单导入）应进一步限制可访问的 root 对象字段。

This component does not provide a default implementation; the host is solely responsible for the safety of its implementation. An unsafe implementation will expose the application to CVE-2022-22963 / CVE-2022-22965-class remote-code-execution risks.

本组件不提供默认实现，宿主对自身实现的安全性负全责。 不安全实现将导致 CVE-2022-22963 / CVE-2022-22965 类 RCE 风险。

Since:
JDK 25, opencode-base-flow V1.0.5
Author:
Leon Soo

  • Method Summary

    Modifier and Type
    Method
    Description
    Object
    evaluate(String expression, FlowContext ctx)
    Evaluates the given expression against the supplied FlowContext.

  • Method Details

    • evaluate

      Object evaluate(String expression, FlowContext ctx)
      Evaluates the given expression against the supplied FlowContext. 在给定 FlowContext 下对表达式求值。
      Parameters:
      expression - the expression source (without the ${...} wrapper) — 去除 ${...} 包裹后的表达式源码
      ctx - the current flow context — 当前流程上下文
      Returns:
      the evaluation result; may be null — 求值结果，允许 null
      Since:
      JDK 25, opencode-base-flow V1.0.5