When using @response and @request for json,i meet with some probems

 LoginController.java:

@Controller @RequestMapping("/user") public class LoginController { @RequestMapping(value="receive", method=RequestMethod.POST, consumes="application/json") @ResponseBody public RegInfo receiveData(@RequestBody RegInfo info){//

    System.out.println("come here");
    System.out.println(info.getRealname());
    return info;
}

}

register.xml:

    $("#sub").click(function(){
    var m = {
            "realname": $("#real_name").val(),
            "phonenumber": $("#phone_number").val()             
        };
    $.ajax({
        type:"POST",
        url:"/demo/user/receive",
        data:m,

        dataType:"json",
        contentType:"application/json; charset=utf-8",
        async:false,
        success:function(data){
            alert("nihao");
        },
        erroe:function(data){
            alert("保存失败 ")
        }
    })
});

RegInfo.java:

public class RegInfo {

private String realname;

private String phonenumber;

//private boolean sex;

public RegInfo(){

}

public void setRealname(String realname){
    this.realname= realname;
}
public String getRealname(){
    return realname;
}

public void setPhonenumber(String phonenumber){
    this.phonenumber = phonenumber;
}
public String getPhonenumber(){
    return phonenumber;
}

demo-servlet.xml:

<!-- 默认的注解映射的支持 -->
<mvc:annotation-driven/>
<context:annotation-config/>

i have imported jackson-annotations-2.1.4.jar、jackson-core-2.1.4.jar、jackson-databind-2.1.4.jar in the lib but i cannot see the print in the console and it point 400 bad request in the chorme.I have tried some ways but it does no effect.