添加 IdGen.randomShortString() 方法

modules/core/src/main/java/com/jeesite/modules/sys/interceptor/LogInterceptor.java

@@ -35,7 +35,7 @@ public class LogInterceptor extends BaseService implements HandlerInterceptor {
 	public boolean preHandle(HttpServletRequest request, HttpServletResponse response, 
 			Object handler) throws Exception {
 		if (StringUtils.isBlank(MDC.get(TRACE_ID))) {
-            MDC.put(TRACE_ID, IdGen.randomBase62(4));
+            MDC.put(TRACE_ID, IdGen.randomShortString());
         }
 		long beginTime = System.currentTimeMillis();// 1、开始时间  
 		startTimeThreadLocal.set(beginTime);		// 线程绑定变量（该数据只有当前请求的线程可见）  

modules/core/src/main/java/com/jeesite/modules/sys/service/support/EmpUserServiceSupport.java

@@ -139,7 +139,7 @@ public class EmpUserServiceSupport extends CrudService<EmpUserDao, EmpUser>
 			// 如果没有设置用户编码，则根据登录名生成一个
 			if (StringUtils.isBlank(user.getUserCode())){
 				userService.genId(user, user.getLoginCode());
-				user.setUserCode(user.getUserCode()+"_"+IdGen.randomBase62(4).toLowerCase());
+				user.setUserCode(user.getUserCode()+"_"+IdGen.randomShortString());
 			}
 			user.setUserType(EmpUser.USER_TYPE_EMPLOYEE);
 			user.setMgrType(EmpUser.MGR_TYPE_NOT_ADMIN);