Introducing LiteFlow: A Lightweight Java Rule Engine for Workflow Orchestration

In daily development, serial or parallel business processes often lack correlation, leading to scattered code when using traditional strategy or template patterns.

LiteFlow is a lightweight yet powerful Java rule engine that enables global orchestration of such flows. It supports rule files in XML, JSON or YAML formats and can store them in various back‑ends such as SQL, Zookeeper, Nacos or Apollo.

The engine provides several component types:

NodeComponent : ordinary component that implements process and can control execution via isContinueOnError , isEnd , etc.

NodeSwitchComponent : switch‑like component that overrides processSwitch to choose the next node.

NodeIfComponent : conditional component that overrides processIf and returns a boolean.

Rule files are written in EL syntax. Typical expressions include:

THEN(a, b, c, d);
WHEN(a, b, c);
SWITCH(a).to(b, c);
IF(x, a, b);

A Maven dependency to embed LiteFlow in a Spring Boot project is:

<dependency>
    <groupId>com.yomahub</groupId>
    <artifactId>liteflow-spring-boot-starter</artifactId>
    <version>2.10.6</version>
</dependency>

Data context objects carry parameters between nodes, allowing each node to read or write the required data.

Typical configuration (application.yml) looks like:

liteflow:
  ruleSource: liteflow/*.el.xml
  retry-count: 0
  print-execution-log: true
  monitor:
    enable-log: true
    period: 300000
  request-id-generator-class: com.platform.orderserver.config.AppRequestIdGenerator
  slot-size: 10240
  main-executor-works: 64
  when-max-wait-seconds: 15
  when-max-workers: 16
  when-queue-limit: 5120
  parse-on-start: true
  enable: true

In a real e‑commerce scenario, an order‑completion flow can be defined as:

<flow>
  <chain name="test_flow">
    THEN(prepareTrade, grantScore, sendMq, WHEN(sendEmail, sendPhone));
  </chain>
</flow>

The flow executes the preparation, score granting, and message queue steps sequentially, while sending email and SMS in parallel.

LiteFlow parses all rules at startup, registers components, and assembles the execution graph, delivering high performance and detailed timing statistics.