报错如下：
在wordspace.xml中找到下面代码.（如果你是用IDEA开发的，wordspace.xml文件在项目的.idea文件夹下面）
<component name="PropertiesComponent">
<property name="WebServerToolWindowFactoryState" value="false" />
<property name="aspect.path.notification.shown" value="true" />
<property name="last_opened_file_path" value="$PROJECT_DIR$/.." />
<property name="nodejs_interpreter_path.stuck_in_default_project" value="undefined stuck path" />
<property name="nodejs_npm_path_reset_for_default_project" value="true" />
<property name="project.structure.last.edited" value="Project" />
<property name="project.structure.proportion" value="0.0" />
<property name="project.structure.side.proportion" value="0.0" />
<property name="settings.editor.selected.configurable" value="project.propCompiler" />
</component>
增加<property name="dynamic.classpath" value="true" />即可.