基于Bmob的在线群聊之群聊天的实现

上一篇已经实现了注册，登录的功能，下面就到实现了在线群聊的功能。

先说一下思路吧，自己可能弄复杂了，所以先说一下思路。

1、实现群聊天的思路

创建一个表用来存储聊天的数据

发送数据调用Bmob的保存数据的方法

给数据表设置表监听，也是Bmob带的方法，只要数据更新那么就将更新的数据保存到本地的数据库

聊天的数据显示是通过查询数据库的方法来显示出来

2、需要在Bmob添加一个用来存储聊天数据的表

public class XdMessage extends BmobObject {//需要继承BmobObject
private String name;//存储消息的用户名
private String msg;//存储消息
private BmobFile icon;//存储发送的图片
private String path;//存储发送图片的路径
//添加get、set方法
public String getPath() {
return path;
}

public void setPath(String path) {
this.path = path;
}

public XdMessage(String name, String msg, String path){
this.name = name;
this.msg = msg;
this.path = path;
}
public BmobFile getIcon() {
return icon;
}
public void setIcon(BmobFile icon) {
this.icon = icon;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getMsg() {
return msg;
}
public void setMsg(String msg) {
this.msg = msg;
}
}

3、发送消息的实现

其实这里说的发送消息就是将数据保存到表格里。

public void send(View v){//点击按钮后执行的方法
final User user = BmobUser.getCurrentUser(User.class);//获取当前用户的信息
final String username = user.getUsername();//将当前的用户名赋值给username
final String text = edit.getText().toString();
if(text.equals("")){
return;
}else {
sendMsg(username,text);//发送消息
}
}

private void sendMsg(final String username, final String text) {
final XdMessage chat = new XdMessage(username,text,"");
chat.save(new SaveListener<String>() {//调用Bmob的保存数据的方法
@Override
public void done(String s, BmobException e) {
if(e == null){//保存成功
edit.setText("");
}else {//保存失败
Toast.makeText(XdChat.this,"发送失败",Toast.LENGTH_LONG).show();
}
}
});
}

4、给表设置监听

BmobRealTimeData data = new BmobRealTimeData();
private void initdata() {
data.start(new ValueEventListener() {
@Override
public void onConnectCompleted(Exception e) {
if(data.isConnected()){
//设置监听的表名
data.subTableUpdate("XdMessage");
}
}
@Override
public void onDataChange(JSONObject jsonObject) {
myAdapter1.notifyDataSetChanged();
if(BmobRealTimeData.ACTION_UPDATETABLE.equals(jsonObject.optString("action"))){
JSONObject data = jsonObject.optJSONObject("data");
//data中有更新的数据的信息，并将数据存入数据库中  insertApi(data.optString("name"),data.optString("msg"),data.optString("path"),data.optString("createdAt"));
chaxun();//查询数据库
lvList.setSelection(lvList.FOCUS_DOWN);//将listview定位在最后一条数据
}
}
});
}

5、数据库的操作

插入数据的方法

public void insertApi(String name,String msg,String path ,String time){
//把要插入的数据全部封装至ContentValues对象
MyOpenHelper oh = new MyOpenHelper(this);
SQLiteDatabase db = oh.getWritableDatabase();
ContentValues values = new ContentValues();
values.put("name", name);//存入的数据
values.put("msg", msg);
values.put("path", path);
values.put("time", time);
db.insert("Xd_message", null, values);//数据库的表名
db.close();
}

查询所有的数据

public void chaxun(){
//把数据库的数据查询出来
//List<LocalMessageXd> Localmsg = new ArrayList<LocalMessageXd>();
Localmsg.clear();
Cursor cursor = db.query("xd_message", null, null, null, null, null, null, null);
while (cursor.moveToNext()) {
String _id = cursor.getString(0);
String name= cursor.getString(1);
String msg = cursor.getString(2);
String path = cursor.getString(3);
String time = cursor.getString(4);
LocalMessageXd q = new LocalMessageXd( _id, name, msg, path, time);
Localmsg.add(q);
}
myAdapter1.notifyDataSetChanged();
lvList.setSelection(lvList.FOCUS_DOWN);
System.out.println("查询完毕" + Localmsg.size());
}

LocalMessageXd

public class LocalMessageXd {
private String _id;
private String name;
private String msg;
private String path;
private String time;

public String get_id() {
return _id;
}

public void set_id(String _id) {
this._id = _id;
}

public String getName() {
return name;
}

public void setName(String name) {
this.name = name;
}

public String getMsg() {
return msg;
}

public void setMsg(String msg) {
this.msg = msg;
}

public String getPath() {
return path;
}

public void setPath(String path) {
this.path = path;
}

public String getTime() {
return time;
}

public void setTime(String time) {
this.time = time;
}

@Override
public String toString() {
return
" name='" + name +
", msg='" + msg +
", path='" + path +
", time='" + time;
}

public LocalMessageXd(String _id, String name, String msg, String path, String time) {
super();
this._id = _id;
this.name = name;
this.msg = msg;
this.path = path;
this.time = time;
}
}

MyOpenHelper类用来创建数据库和表

public class MyOpenHelper extends SQLiteOpenHelper{
public MyOpenHelper(Context context) {
super(context, "test.db", null, 1);
}

@Override
public void onCreate(SQLiteDatabase db) {
//聊天的数据库
db.execSQL("create table xd_message(_id integer primary key autoincrement, name char(10),msg char(20), path char(20),time char(20))");
System.out.println("数据库被创建了");
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
System.out.println("数据库升级了");
}
}

MyAdapter1类

private class MyAdapter1 extends BaseAdapter{

@Override
public int getCount() {
return Localmsg.size();
}

@Override
public Object getItem(int position) {
return Localmsg.get(position);
}

@Override
public long getItemId(int position) {
return position;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
System.out.println("getView");
MyAdapter1.ViewHolder holder = null;
if(convertView == null){
holder = new MyAdapter1.ViewHolder();
LayoutInflater inflater = LayoutInflater.from(XdChat.this);
convertView = inflater.inflate(R.layout.item_chat, null);
holder.my_head = (ImageView) convertView.findViewById(R.id.my_head);
holder.my_name = (TextView) convertView.findViewById(R.id.my_name);
holder.tv_my = (TextView) convertView.findViewById(R.id.tv_my);
holder.iv_my = (ImageView) convertView.findViewById(R.id.iv_my);
holder.my_time = (TextView) convertView.findViewById(R.id.my_time);
holder.other_time = (TextView) convertView.findViewById(R.id.other_time);
holder.other_head = (ImageView) convertView.findViewById(R.id.other_head);
holder.other_name = (TextView) convertView.findViewById(R.id.other_name);
holder.tv_other = (TextView) convertView.findViewById(R.id.tv_other);
holder.iv_other = (ImageView) convertView.findViewById(R.id.iv_other);
convertView.setTag(holder);
}else{
holder = (MyAdapter1.ViewHolder) convertView.getTag();
}
LocalMessageXd chat = Localmsg.get(position);
User user = BmobUser.getCurrentUser(User.class);
if(chat.getName().equals(user.getUsername())){
holder.other_head.setVisibility(View.GONE);
holder.other_name.setVisibility(View.GONE);
holder.tv_other.setVisibility(View.GONE);

holder.iv_other.setVisibility(View.GONE);
holder.my_head.setVisibility(View.VISIBLE);
// downloadFile1(chat.getName(),holder.my_head);
String path = chaxunHeadPath(chat.getName());
downloadFile(chat.getName(),holder.my_head,path);
holder.my_name.setVisibility(View.VISIBLE);
holder.my_name.setText(chat.getName());

holder.other_time.setVisibility(View.GONE);
holder.my_time.setVisibility(View.VISIBLE);
String time = chat.getTime().substring(5);
holder.my_time.setText(time + "  ");
String msg = chat.getMsg();
if(msg.equals("")){
holder.tv_my.setVisibility(View.GONE);
holder.iv_my.setVisibility(View.VISIBLE);
/*  Bitmap bmp= BitmapFactory.decodeFile(chat.getPath());
holder.iv_my.setImageBitmap(bmp);*/
downloadFile(chat.getName(),holder.iv_my,chat.getPath());
}else {
holder.iv_my.setVisibility(View.GONE);
holder.tv_my.setVisibility(View.VISIBLE);
// holder.tv_my.setText(chat.getTime() + "\n"+ chat.getMsg());
holder.tv_my.setText(chat.getMsg());
}

}
else{
holder.my_head.setVisibility(View.GONE);
holder.my_name.setVisibility(View.GONE);
holder.tv_my.setVisibility(View.GONE);
holder.iv_my.setVisibility(View.GONE);

holder.other_name.setText(chat.getName());
holder.other_head.setVisibility(View.VISIBLE);
holder.my_time.setVisibility(View.GONE);
holder.other_time.setVisibility(View.VISIBLE);
String time = chat.getTime().substring(5);
holder.other_time.setText("  " + time);
//  downloadFile1(chat.getName(),holder.other_head);
String path = chaxunHeadPath(chat.getName());
if(path.equals("")){
holder.other_head.setImageResource(R.drawable.default_icon_user);
}else {
downloadFile(chat.getName(),holder.other_head,path);
}
holder.other_name.setVisibility(View.VISIBLE);
if(chat.getMsg().equals("")){
holder.tv_other.setVisibility(View.GONE);
holder.iv_other.setVisibility(View.VISIBLE);
/*  Bitmap bmp= BitmapFactory.decodeFile(chat.getPath());
holder.iv_other.setImageBitmap(bmp);*/
downloadFile(chat.getName(),holder.iv_other,chat.getPath());
}else {
holder.iv_other.setVisibility(View.GONE);
holder.tv_other.setVisibility(View.VISIBLE);
// holder.tv_other.setText(chat.getTime() + "\n" + chat.getMsg());
holder.tv_other.setText(chat.getMsg());
}

}
return convertView;
}
class ViewHolder{
ImageView my_head;
TextView my_name;
TextView tv_my;
TextView my_time;
ImageView iv_my;
ImageView other_head;
TextView other_name;
TextView tv_other;
ImageView iv_other;
TextView other_time;
}
}