执行器注册方式切换优化，切换自动注册时主动同步在线机器，避免执行器为空的问题；

doc/XXL-JOB官方文档.md

@@ -1243,7 +1243,8 @@ Tips: 历史版本(V1.3.x)目前已经Release至稳定版本, 进入维护阶段
 - 27、执行器通讯线程优化，corePoolSize从256降低至32；
 - 28、新增任务运行模式 "GLUE模式(PowerShell) "，支持PowerShell脚本任务；
 - 29、GLUE脚本文件自动清理功能，及时清理过期脚本文件；
-- 30、【迭代中】分片任务失败重试优化，仅重试当前失败的分片；
+- 30、执行器注册方式切换优化，切换自动注册时主动同步在线机器，避免执行器为空的问题；
+- 31、【迭代中】分片任务失败重试优化，仅重试当前失败的分片；
 
 
 ### TODO LIST

xxl-job-admin/src/main/java/com/xxl/job/admin/controller/JobGroupController.java

 package com.xxl.job.admin.controller;
 
 import com.xxl.job.admin.core.model.XxlJobGroup;
+import com.xxl.job.admin.core.model.XxlJobRegistry;
+import com.xxl.job.admin.core.schedule.XxlJobDynamicScheduler;
 import com.xxl.job.admin.core.util.I18nUtil;
 import com.xxl.job.admin.dao.XxlJobGroupDao;
 import com.xxl.job.admin.dao.XxlJobInfoDao;
 import com.xxl.job.core.biz.model.ReturnT;
+import com.xxl.job.core.enums.RegistryConfig;
+import org.apache.commons.collections4.CollectionUtils;
 import org.apache.commons.lang3.StringUtils;
 import org.springframework.stereotype.Controller;
 import org.springframework.ui.Model;
@@ -12,6 +16,9 @@ import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.ResponseBody;
 
 import javax.annotation.Resource;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashMap;
 import java.util.List;
 
 /**
@@ -80,7 +87,17 @@ public class JobGroupController {
 		if (xxlJobGroup.getTitle()==null || StringUtils.isBlank(xxlJobGroup.getTitle())) {
 			return new ReturnT<String>(500, (I18nUtil.getString("system_please_input") + I18nUtil.getString("jobgroup_field_title")) );
 		}
-		if (xxlJobGroup.getAddressType()!=0) {
+		if (xxlJobGroup.getAddressType() == 0) {
+			// 0=自动注册
+			List<String> registryList = findRegistryByAppName(xxlJobGroup.getAppName());
+			String addressListStr = null;
+			if (CollectionUtils.isNotEmpty(registryList)) {
+				Collections.sort(registryList);
+				addressListStr = StringUtils.join(registryList, ",");
+			}
+			xxlJobGroup.setAddressList(addressListStr);
+		} else {
+			// 1=手动录入
 			if (StringUtils.isBlank(xxlJobGroup.getAddressList())) {
 				return new ReturnT<String>(500, I18nUtil.getString("jobgroup_field_addressType_limit") );
 			}
@@ -96,6 +113,28 @@ public class JobGroupController {
 		return (ret>0)?ReturnT.SUCCESS:ReturnT.FAIL;
 	}
 
+	private List<String> findRegistryByAppName(String appNameParam){
+		HashMap<String, List<String>> appAddressMap = new HashMap<String, List<String>>();
+		List<XxlJobRegistry> list = XxlJobDynamicScheduler.xxlJobRegistryDao.findAll(RegistryConfig.DEAD_TIMEOUT);
+		if (list != null) {
+			for (XxlJobRegistry item: list) {
+				if (RegistryConfig.RegistType.EXECUTOR.name().equals(item.getRegistryGroup())) {
+					String appName = item.getRegistryKey();
+					List<String> registryList = appAddressMap.get(appName);
+					if (registryList == null) {
+						registryList = new ArrayList<String>();
+					}
+
+					if (!registryList.contains(item.getRegistryValue())) {
+						registryList.add(item.getRegistryValue());
+					}
+					appAddressMap.put(appName, registryList);
+				}
+			}
+		}
+		return appAddressMap.get(appNameParam);
+	}
+
 	@RequestMapping("/remove")
 	@ResponseBody
 	public ReturnT<String> remove(int id){