feat(core): 支持无 chain 配置启动

放宽 DTD 与 JSON 解析对 chain 节点的强校验，允许 ruleSource 下未定义任何 chain 时正常启动；新增 NoChainELSpringbootTest 用例。

liteflow-core/src/main/java/com/yomahub/liteflow/core/FlowExecutor.java

@@ -11,7 +11,6 @@ package com.yomahub.liteflow.core;
 import cn.hutool.core.collection.CollUtil;
 import cn.hutool.core.collection.ListUtil;
 import cn.hutool.core.lang.Tuple;
-import cn.hutool.core.map.MapUtil;
 import cn.hutool.core.util.*;
 import cn.hutool.crypto.digest.MD5;
 import com.yomahub.liteflow.builder.el.LiteFlowChainELBuilder;
@@ -217,16 +216,6 @@ public class FlowExecutor {
 			}
 		}
 
-		// 如果是ruleSource方式的，最后判断下有没有解析出来,如果没有解析出来则报错
-		if (StrUtil.isBlank(liteflowConfig.getRuleSourceExtData())
-				&& MapUtil.isEmpty(liteflowConfig.getRuleSourceExtDataMap())) {
-			if (FlowBus.getChainMap().isEmpty()) {
-				String errMsg = StrUtil.format("no valid rule config found in rule path [{}]",
-						liteflowConfig.getRuleSource());
-				throw new ConfigErrorException(errMsg);
-			}
-		}
-
 		// 执行钩子
 		if (isStart) {
 			FlowInitHook.executeHook();
@@ -722,4 +711,4 @@ public class FlowExecutor {
 	public AtomicBoolean getStartUpPhase() {
 		return startUpPhase;
 	}
-}
+}

liteflow-core/src/main/java/com/yomahub/liteflow/parser/helper/ParserHelper.java

@@ -226,8 +226,13 @@ public class ParserHelper {
         // 这样就不用去像之前的版本那样回归调用
         // 同时也解决了不能循环依赖的问题
         flowJsonObjectList.forEach(jsonObject -> {
+            JsonNode flowNode = jsonObject.get(FLOW);
+            if (flowNode == null || !flowNode.has(CHAIN)) {
+                return;
+            }
+
             // 解析chain节点
-            Iterator<JsonNode> iterator = jsonObject.get(FLOW).get(CHAIN).elements();
+            Iterator<JsonNode> iterator = flowNode.get(CHAIN).elements();
             // 先在元数据里放上chain
             while (iterator.hasNext()) {
                 JsonNode innerJsonObject = iterator.next();

liteflow-core/src/main/resources/dtd/liteflow.dtd

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8" ?>
 
-<!ELEMENT flow  ((nodes)? , (chain)+)>
+<!ELEMENT flow  ((nodes)? , (chain)*)>
 <!ELEMENT nodes  (node)+>
 <!ELEMENT node  (#PCDATA | EMPTY)*>
 <!ELEMENT chain ((route)? | (body)? | #PCDATA)>
@@ -23,4 +23,4 @@
         enable (true|false) #IMPLIED
         namespace CDATA #IMPLIED
         thread-pool-executor-class CDATA #IMPLIED
-        >
+        >

liteflow-testcase-el/liteflow-testcase-el-springboot/src/test/java/com/yomahub/liteflow/test/base/NoChainELSpringbootTest.java

@@ -0,0 +1,35 @@
+package com.yomahub.liteflow.test.base;
+
+import com.yomahub.liteflow.core.FlowExecutor;
+import com.yomahub.liteflow.flow.FlowBus;
+import com.yomahub.liteflow.test.BaseTest;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.context.annotation.ComponentScan;
+import org.springframework.test.context.TestPropertySource;
+
+import javax.annotation.Resource;
+
+/**
+ * springboot环境下没有chain的启动测试
+ *
+ * @author Bryan.Zhang
+ */
+@TestPropertySource(value = "classpath:/base/noChain/application.properties")
+@SpringBootTest(classes = NoChainELSpringbootTest.class)
+@EnableAutoConfiguration
+@ComponentScan({ "com.yomahub.liteflow.test.base.cmp" })
+public class NoChainELSpringbootTest extends BaseTest {
+
+	@Resource
+	private FlowExecutor flowExecutor;
+
+	@Test
+	public void testStartWithoutChain() {
+		Assertions.assertNotNull(flowExecutor);
+		Assertions.assertTrue(FlowBus.getChainMap().isEmpty());
+	}
+
+}

liteflow-testcase-el/liteflow-testcase-el-springboot/src/test/resources/base/noChain/application.properties

@@ -0,0 +1 @@
+liteflow.rule-source=base/noChain/flow.el.xml

liteflow-testcase-el/liteflow-testcase-el-springboot/src/test/resources/base/noChain/flow.el.xml

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE flow PUBLIC  "liteflow" "liteflow.dtd">
+<flow>
+</flow>