PowerJob的Evaluator方法工作流程源码解读
作者:codecraft
这篇文章主要介绍了PowerJob的Evaluator方法工作流程源码解读,有需要的朋友可以借鉴参考下,希望能够有所帮助,祝大家多多进步,早日升职加薪
序
本文主要研究一下PowerJob的Evaluator
Evaluator
tech/powerjob/server/core/evaluator/Evaluator.java
public interface Evaluator { /** * 使用给定输入计算表达式 * * @param expression 可执行的表达式 * @param input 输入 * @return 计算结果 */ Object evaluate(String expression, Object input); }
Evaluator接口定义了evaluate方法,它有expression和input两个参数,返回计算结果
GroovyEvaluator
tech/powerjob/server/core/evaluator/GroovyEvaluator.java
@Slf4j @Component public class GroovyEvaluator implements Evaluator { private static final ScriptEngine ENGINE = new ScriptEngineManager().getEngineByName("groovy"); @Override @SneakyThrows public Object evaluate(String expression, Object input) { Bindings bindings = ENGINE.createBindings(); bindings.put("context", input); return ENGINE.eval(expression, bindings); } }
GroovyEvaluator实现了Evaluator,它内置了一个groovy的ScriptEngine,其evaluate方法先创建bindings,然后传入参数,最后通过ENGINE.eval(expression, bindings)计算结果
DecisionNodeHandler
tech/powerjob/server/core/workflow/hanlder/impl/DecisionNodeHandler.java
@Slf4j @Component public class DecisionNodeHandler implements ControlNodeHandler { private final GroovyEvaluator groovyEvaluator = new GroovyEvaluator(); /** * 处理判断节点 * 1. 执行脚本 * 2. 根据返回值 disable 掉相应的边以及节点 */ @Override public void handle(PEWorkflowDAG.Node node, PEWorkflowDAG dag, WorkflowInstanceInfoDO wfInstanceInfo) { String script = node.getNodeParams(); if (StringUtils.isBlank(script)) { log.error("[Workflow-{}|{}]decision node's param is blank! nodeId:{}", wfInstanceInfo.getWorkflowId(), wfInstanceInfo.getWfInstanceId(), node.getNodeId()); throw new PowerJobException("decision node's param is blank!"); } // wfContext must be a map HashMap<String, String> wfContext = JSON.parseObject(wfInstanceInfo.getWfContext(), new TypeReference<HashMap<String, String>>() { }); Object result; try { result = groovyEvaluator.evaluate(script, wfContext); } catch (Exception e) { log.error("[Workflow-{}|{}]failed to evaluate decision node,nodeId:{}", wfInstanceInfo.getWorkflowId(), wfInstanceInfo.getWfInstanceId(), node.getNodeId(), e); throw new PowerJobException("can't evaluate decision node!"); } boolean finalRes; if (result instanceof Boolean) { finalRes = ((Boolean) result); } else if (result instanceof Number) { finalRes = ((Number) result).doubleValue() > 0; } else { log.error("[Workflow-{}|{}]decision node's return value is illegal,nodeId:{},result:{}", wfInstanceInfo.getWorkflowId(), wfInstanceInfo.getWfInstanceId(), node.getNodeId(), JsonUtils.toJSONString(result)); throw new PowerJobException("decision node's return value is illegal!"); } handleDag(finalRes, node, dag); } //...... }
DecisionNodeHandler实例化了groovyEvaluator,其handle方法通过groovyEvaluator.evaluate(script, wfContext)来计算node的结果
小结
PowerJob的Evaluator接口定义了evaluate方法,它有expression和input两个参数,返回计算结果;GroovyEvaluator实现了Evaluator,它内置了一个groovy的ScriptEngine,其evaluate方法先创建bindings,然后传入参数,最后通过ENGINE.eval(expression, bindings)计算结果。
以上就是PowerJob的Evaluator方法工作流程源码解读的详细内容,更多关于PowerJob Evaluator工作流程的资料请关注脚本之家其它相关文章!