SpringMVC用@RequestBody反序列化时出错? 400 报错

SpringMVC用@RequestBody反序列化时出错? 400 报错

public Object selectByExample(@RequestBody SysRole sysRole)

json是这样的

{"id":"","rolename":"root","sort":"","info":"","lastModifyTime":"","status":"","pageNum":"1","pageSize":"2"};

实体类SysRole是这样的

public class SysRole extends MyPage implements Serializable{
    private Integer id;

    private String rolename;

    private Integer sort;

    private String info;

    private Date lastModifyTime;

    private Integer status;

public class MyPage implements Serializable{
    //当前页
    private int pageNum=1;
    //每页的数量
    private int pageSize=10;

get和set省略