var carinfo ={
            emptyseats : emptyseats,
            carnum : carnum,
            carbrand : carbrand,
            driverage : driverage,
            cardesc : cardesc,
            isdown: isdown,
            issmoking : issmoking,
            iseating: iseating,
            userid: userid
        };

        var URL = "savecarinfo.do";

        $.ajax({
            type : "post",// 使用post方法访问后台
            dataType : "json",// 返回json格式的数据
            url : URL,// 要访问的后台地址
            async : "false",// 采用同步方式，必须先进行数据拉取后显示界面
            contentType : "application/json;charset=utf-8",
            data : {
                carInfo:carinfo
            }// 要发送的数据
        });

net.sf.json.JSONException: A JSONObject text must begin with '{' at character 1 of carInfo[emptyseats]=1&carInfo[carnum]=&carInfo[carbrand]=&carInfo[driverage]=&carInfo[cardesc]=&carInfo[isdown]=0&carInfo[issmoking]=1&carInfo[iseating]=0&carInfo[userid]=s24f566
    at net.sf.json.util.JSONTokener.syntaxError(JSONTokener.java:512)
    at net.sf.json.JSONObject._fromJSONTokener(JSONObject.java:1096)
    at net.sf.json.JSONObject._fromString(JSONObject.java:1317)
    at net.sf.json.JSONObject.fromObject(JSONObject.java:185)
    at net.sf.json.JSONObject.fromObject(JSONObject.java:154)
    at com.carpooling.controller.CarinfoController.saveCarinfo(CarinfoController.java:57)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.springframework.web.bind.annotation.support.HandlerMethodInvoker.invokeHandlerMethod(HandlerMethodInvoker.java:176)
    at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.invokeHandlerMethod(AnnotationMethodHandlerAdapter.java:426)
    at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle(AnnotationMethodHandlerAdapter.java:414)
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:790)
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:719)
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:644)
    at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:560)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:641)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:225)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
    at org.apache.catalina.authenticator.AuthenticatorBase.invok