Why LiteFlow Is the Go‑to Rule Engine for Complex Business Logic

LiteFlow is an open‑source lightweight rule engine that decouples complex business logic by splitting a waterfall‑style process into independent components (nodes) orchestrated with a DSL. Each component processes a single step and shares a common context (workbench), eliminating inter‑component method calls.

Key Capabilities

Component‑based decomposition : Long chains are broken into single‑purpose components.

Rule‑driven orchestration : EL expressions define serial, parallel, conditional and loop structures.

Multi‑language script support : Java, JavaScript, Groovy, QLExpress, Python, Lua, Aviator, etc. Java script compilation was accelerated 200× in v2.15.3 (30 s → 150 ms for 2000 scripts).

Hot deployment : Rules and scripts stored in DB or registries (Nacos, Etcd, Zookeeper) take effect instantly without restart.

Visual editor : LiteFlowX provides a drag‑and‑drop UI.

Built‑in monitoring : Command‑line monitor reports component execution time ranking.

Performance Highlights

Upgrading the underlying engine from QLExpress 3 to QLExpress 4 (v2.15.2) yields:

Compile TPS: 2,739 → 3,636 ops (+32%).

Context injection: 55,826 → 222,625 ops (+300%).

Benchmark used 2 warm‑up runs and 3 measured runs.

Quick Start

Maven Dependency

<dependency>
  <groupId>com.yomahub</groupId>
  <artifactId>liteflow-spring-boot-starter</artifactId>
  <version>2.15.3</version>
</dependency>

Supports JDK 8‑25; for JDK 9+ use v2.15.0+ without extra JVM arguments.

Rule File Configuration

liteflow.rule-source=config/flow.el.xml

Example resources/config/flow.el.xml:

<flow>
  <chain name="orderChain">
    THEN(
      validateOrder,
      WHEN(checkStock, calcPrice),
      riskCheck,
      saveOrder
    );
  </chain>
</flow>

THEN

denotes serial execution; WHEN runs its arguments in parallel.

Component Definition

@LiteflowComponent("validateOrder")
public class ValidateOrderCmp extends NodeComponent {
    @Override
    public void process() {
        OrderContext ctx = this.getContextBean(OrderContext.class);
        Order order = ctx.getOrder();
        if (order.getAmount() <= 0) {
            throw new IllegalArgumentException("订单金额必须大于0");
        }
        ctx.setValid(true);
    }
}

Components obtain shared data via getContextBean, avoiding explicit parameter passing.

Typical Use Cases

E‑commerce pricing engine : Separate base price, member discount, coupon, activity discount, final price calculation and persistence into distinct components; add new discount types by adding a component only.

Complex approval process : Implement business logic such as budget check, parallel supplier queries, risk rules, and order generation while delegating task routing to a BPM engine.

Data‑cleansing ETL : Componentize deduplication, format conversion, enrichment, and quality checks; configure different chains per data source.

Real‑time risk decision : Adjust fraud thresholds via hot‑deployed script changes without downtime.

EL Syntax Overview

Serial : THEN(a, b, c) or SER(a, b, c) Parallel : WHEN(a, b, c) or PAR(a, b, c) Nested : THEN(a, WHEN(b, THEN(c, d)), e) Ignore errors : WHEN(b, c, d).ignoreError(true) Any completion : WHEN(b, c, d).any(true) Must‑wait nodes : WHEN(b, c, d).must(b, c) Percentage completion :

WHEN(a, b, c, d, e).percentage(0.6)

When Not to Use

Pure role‑based approval flows (use Flowable/Flowlong).

Very simple 2‑3 step processes where the overhead outweighs benefits.

Massive parallel computations (hundreds of components) better suited for Spark/Flink.

Repository

https://gitee.com/dromara/liteFlow

LiteFlowX UI: https://gitee.com/liupeiqiang/LiteFlowX

Liquor dynamic compiler (used for Java script acceleration): https://gitee.com/noear/liquor