intellij Idea 同一個project下模塊module 之間是如何實現引用？

廢話不說，idea模塊（module） 是如何實現引用的，若A模塊需要使用B模塊裏的東西可以直接在 A模塊組織文件 A.iml 中添加一句

<orderEntry type="module" module-name="B模塊名字" />

如下我的一個例子 是demomain 模塊應用了democore模塊 

<?xml version="1.0" encoding="UTF-8"?>
<module org.jetbrains.idea.maven.project.MavenProjectsManager.isMavenModule="true" type="JAVA_MODULE" version="4">
  <component name="FacetManager">
    <facet type="Spring" name="Spring">
      <configuration />
    </facet>
  </component>
  <component name="NewModuleRootManager" LANGUAGE_LEVEL="JDK_1_8">
    <output url="file://$MODULE_DIR$/demomain/target/classes" />
    <output-test url="file://$MODULE_DIR$/demomain/target/test-classes" />
    <content url="file://$MODULE_DIR$/demomain">
      <sourceFolder url="file://$MODULE_DIR$/demomain/src/main/java" isTestSource="false" />
      <sourceFolder url="file://$MODULE_DIR$/demomain/src/test/java" isTestSource="true" />
      <excludeFolder url="file://$MODULE_DIR$/demomain/target" />
    </content>
    <orderEntry type="inheritedJdk" />
    <orderEntry type="sourceFolder" forTests="false" />
    <orderEntry type="library" scope="TEST" name="Maven: junit:junit:4.11" level="project" />
    <orderEntry type="library" scope="TEST" name="Maven: org.hamcrest:hamcrest-core:1.3" level="project" />
    <orderEntry type="module" module-name="democore" />
    <orderEntry type="library" name="Maven: org.activiti:activiti-engine:5.22.0" level="project" />
    <orderEntry type="library" name="Maven: org.activiti:activiti-bpmn-converter:5.22.0" level="project" />
    .................
    <orderEntry type="library" scope="PROVIDED" name="Maven: javax.servlet:javax.servlet-api:3.1.0" level="project" />
    <orderEntry type="library" scope="PROVIDED" name="Maven: javax.servlet.jsp:javax.servlet.jsp-api:2.3.1" level="project" />
    <orderEntry type="library" scope="PROVIDED" name="Maven: org.projectlombok:lombok:1.16.20" level="project" />
    <orderEntry type="library" name="Maven: mysql:mysql-connector-java:5.1.21" level="project" />
  </component>
</module>