本案例中 username 记录成 userId了， nick 始终为空。。。，这是 getNick() 取得的就是 username。。。。。

如果想自己取得自己系统的nickname则 做以下调整即可，即：重写了 getNick 和 setNick, 这是 会将nick保存至本地sqlite数据库

/** * Copyright (C) 2013-2014 EaseMob Technologies. All rights reserved. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at *     http://www.apache.org/licenses/LICENSE-2.0 * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */package com.easemob.chatuidemo.domain;import com.easemob.chat.EMContact;public class User extends EMContact {    private int unreadMsgCount;    private String header;    private String avatar;    private String yxq_nick;        public User(){}        public User(String username){        this.username = username;    }    public String getHeader() {        return header;    }    public void setHeader(String header) {        this.header = header;    }    public int getUnreadMsgCount() {        return unreadMsgCount;    }    public void setUnreadMsgCount(int unreadMsgCount) {        this.unreadMsgCount = unreadMsgCount;    }            public String getAvatar() {        return avatar;    }    public void setAvatar(String avatar) {        this.avatar = avatar;    }    @Override    public int hashCode() {        return 17 * getUsername().hashCode();    }    @Override    public boolean equals(Object o) {        if (o == null || !(o instanceof User)) {            return false;        }        return getUsername().equals(((User) o).getUsername());    }    @Override    public String toString() {        return nick == null ? username : nick;    }        @Override    public void setNick(String nick) {        // TODO Auto-generated method stub                yxq_nick=nick;    }    @Override    public String getNick() {        // TODO Auto-generated method stub//        return super.getNick();        return yxq_nick == null ? username : yxq_nick;    }}