HTTPS请求为什么会降级为HTTP

用HTTP请求没有任何问题，用HTTPS请求就报错，这是为什么？

这是后台代码块

报错的是越界 String question_vip = selectByFilter2.get(0).getQuestion_vip();

List<User> selectByFilter2 = uservice.selectByFilter(u);
		String question_vip = selectByFilter2.get(0).getQuestion_vip();
		if (type != "") {
			if (question_vip.equals("1")) {
				Map<String, Object> map = new HashMap<>();
				map.put("data", selectByFilter);
				String jsonString = JSON.toJSONString(map);
				writer.write(jsonString);
				writer.flush();
			} else {
				Map<String, Object> map = new HashMap<>();
				map.put("data", selectByFilter);
				String jsonString = JSON.toJSONString(map);
				writer.write(jsonString);
				writer.flush();
			}
		} else {
			Map<String, Object> map = new HashMap<>();
			map.put("msg", "条件错误");
			String jsonString = JSON.toJSONString(map);
			writer.write(jsonString);
			writer.flush();
		}

报错内容

Type 异常报告

消息 Request processing failed; nested exception is java.lang.IndexOutOfBoundsException: Index: 0, Size: 0

描述 服务器遇到一个意外的情况，阻止它完成请求。

Exception

org.springframework.web.util.NestedServletException: Request processing failed; nested exception is java.lang.IndexOutOfBoundsException: Index: 0, Size: 0
	org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:978)
	org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:868)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:660)
	org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:842)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
	org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
	org.apache.logging.log4j.core.web.Log4jServletFilter.doFilter(Log4jServletFilter.java:66)
Root Cause

java.lang.IndexOutOfBoundsException: Index: 0, Size: 0
	java.util.ArrayList.rangeCheck(ArrayList.java:653)
	java.util.ArrayList.get(ArrayList.java:429)
	main.controller.qMunController.qMun(qMunController.java:53)
	sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	java.lang.reflect.Method.invoke(Method.java:498)
	org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:221)
	org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:137)
	org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:110)
	org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:777)
	org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:706)
	org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
	org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:943)
	org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:877)
	org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:966)
	org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:868)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:660)
	org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:842)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
	org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
	org.apache.logging.log4j.core.web.Log4jServletFilter.doFilter(Log4jServletFilter.java:66)

注意用HTTP请求是正常的不会出错
望各路大神指点，谢谢！