tomcat重启后，session中的某些数据丢失

今天发现一个问题，当tomcat重启后，session中的某些数据丢失。

由于系统需要，把一些内容以HashMap，String，和自定义的User对象等方式放到了session当中。

但是奇怪的是，tomcat重启之后，session中只有User对象丢失，其他内容还在。经过网上查找发现

为了将session中的对象也存储起来，那么session中的对象就必须是可序列化的，即实现serializable接口。

实现此接口问题得到解决。

User类：

import java.io.Serializable;
public class User implements Serializable{
private static final long serialVersionUID = 8565543877453611545L;
    private String USERID;
    private String USERNAME;
    private String ROLE_ID;
    private String ROLENAME;
    private String DEPARTMENT;
    private String DEPART_ID;
    private String EMPLEVEL;
    private String EMAIL;
    private String USERCODE;
    private String DEPARTCODE;
    private String MOBILE;
    private String RZSJ;


    @Override
    public String toString(){
        return  USERID+","
                +USERNAME+","
                +ROLE_ID+","
                +ROLENAME+","
                +DEPART_ID+","
                +DEPARTMENT+","
                +EMPLEVEL+","
                +EMAIL+","
                +USERCODE+","
                +DEPARTCODE+","
                +MOBILE+","
                +RZSJ+","
                ;
    }

    ...