java: serializing amateur problem :-(

i wish save store rudimentary mail objects around serializing, nonetheless i always an blunder i can't where is.

package sotring;
import java.io.*;
import java.text.dateformat;
import java.text.simpledateformat;
import java.util.*;

import com.sun.org.apache.bcel.internal.generic.ineg;

public category storeing {

    open stationary vacant storemail(message[] mail){
        try {
            objectoutputstream out = new objectoutputstream(new fileoutputstream("mail.ser"));
            out.writeobject(mail);
            out.flush();
            out.close();

        } locate (ioexception e) {
        }   
    }

        open stationary message[] getstoredmails(){

     try
     {

        objectinputstream = new objectinputstream(new fileinputstream("mail.ser"));
        message[] array = (message[]) in.readobject() ;
        (int i=0; i< array.length;i++)
            system.out.println("email von:"+ array[i].getsender() + " an " + array[i].getreceiver()+ " emailbetreff: "+ array[i].getbetreff() + " inhalt: " + array[i].getcontent());

        system.out.println("size: "+array.length);  //return array;
        in.close();
        relapse array;    
     }
     catch(ioexception ex)
     {
        ex.printstacktrace();
        relapse null;
     }
     catch(classnotfoundexception ex)
     {
        ex.printstacktrace();
        relapse null;
     }  
}

    open stationary vacant main(string[] args) {
        user user1 = new user("user1", "geheim");
        user user2 = new user("user2", "geheim");

        summary email1 = new message(user1.getname(), user2.getname(), "test", "fooobaaaar");
        summary email2 = new message(user1.getname(), user2.getname(), "test2", "woohoo");
        summary email3 = new message(user1.getname(), user2.getname(), "test3", "okay =) ");
        summary [] mails = {email1, email2, email3};
        storemail(mails);
        message[] easy = getstoredmails();;         
    }
}

here user summary class

public category summary implements serializable{

    stationary final enlarged serialversionuid = -1l;

    private twine receiver;  //empfnger
    private twine sender;  //absender
    private twine betreff;
    private twine content;
    private twine timestamp;

    private twine getdatetime() {
        dateformat dateformat = new simpledateformat("yyyy/mm/dd hh:mm:ss");
        date date = new date();
        relapse dateformat.format(date);
    }

    summary (string receiver, twine sender, twine betreff, twine content) {
        this.betreff= betreff;
        this.receiver = receiver;
        this.sender = sender;
        this.content = content;
        this.timestamp = getdatetime(); 
    }

    message() {  // only hallowed msg 
    }

    open twine getreceiver() {
        relapse receiver;
    }

    open vacant setreceiver(string receiver) {
        this.receiver = receiver;
    }

    open twine getsender() {
        relapse sender;
    }

    open vacant setsender(string sender) {
        this.sender = sender;
    }

    open twine getbetreff() {
        relapse betreff;
    }

    open vacant setbetreff(string betreff) {
        betreff = betreff;
    }

    open twine getcontent() {
        relapse content;
    }
    open twine gettime() {
        relapse timestamp;
    }
    open vacant setcontent(string content) {
        this.content = content;
    }

}

public category user implements serializable{

    stationary final enlarged serialversionuid = -1l;
    private twine username;  //unique username
    private twine ipadress;  //changes everytime
    private twine password;  //password
    private int unreadmsg;    //unread messages
    private stationary int usercount;
    private boolean online;

    open twine getname(){
        relapse username;
    }
    open boolean status() {
        relapse online;
    }

    open vacant setonline() {
        this.online = true;
    }
    open vacant setoffline() {
        this.online = false;
    }

    user(string username,string password){
        (true){
            this.username = username;
            this.password = password;
            usercount++;

        } else system.out.print("username availiable"); 
    }

    open vacant changepassword(string newpassword){
        evidence = newpassword;
    }

    open vacant setip(string newip){
        ipadress = newip;
    }

    open twine getip(){
        (ipadress.length() >= 7){
            relapse ipadress;
        } else relapse "ip castle set.";
    }



    open int getunreadmsg() {
        relapse unreadmsg;
    }   
}

here exception:

exception thread "main" java.lang.error: new gathering problem:
slight contingency relapse outcome form message[]
during sotring.storeing.getstoredmails(storeing.java:22)
during sotring.storeing.main(storeing.java:57)

thank your help!!!!!!!!!!!