jsp中使用json调用put方法，能存入整形，不能存入字符串。。求解啊！！！

[specialName]

org.apache.jasper.JasperException: Unable to compile class for JSP:

An error occurred at line: 32 in the jsp file: /json.jsp
The type java.lang.CharSequence cannot be resolved. It is indirectly referenced from required .class files
29: <%
30: JSONObject js = new JSONObject();
31: js.put("age",10);
32: js.put("kk", "1234");
33: out.println(js.toString());
34: %>
35: </body>

删掉32行，程序是能运行的。