js接收java后台的传值，java后台传值给js

后台action：

request.put("toposJson",“xxxxxxxx”);

前台jsp：

<%

//json
String toposJson = (String)request.getAttribute("toposJson");

%>

前台js获取值

<script type="text/javascript">

//json格式topo数据
var toposJson ="<%=toposJson%>";

</script>

另一种方式就是异步处理方式了：Ajax