安卓android+WebSocket实现简易QQ聊天室

本篇仅介绍实现聊天室的前端，也就是安卓端代码，后端的实现看链接说明

链接说明

1.后端使用了spring boot 框架，若不熟悉，有关spring boot 入门教程请戳此链接使用Intellij IDEA开发第一个spring boot项目
2.websocket后端实现细节戳此链接spring boot练习–利用websocket实现QQ聊天室

界面展示

说明

有两个界面，第一个是登陆界面，我借用了我之前实现的登陆界面，并做了一些微调。需要输入ID和名字，测试的时候输入的ID不能重复，第二个是名字用于界面展示，登陆后跳转入第二个界面，就可以在聊天室里聊天了。

下面图模拟了一组场景，大青儿先进入聊天室，然后小明进入，互相发一段消息后，小明退出聊天室。

大青儿界面变化

小明界面变化

代码部分

这里仅展示安卓的代码，后端代码详见上面链接说明。

文件的简单介绍

Activity文件：LoginActivity.java,ChatActivity.java,与其对应布局文件activity_login.xml,activity_chat.xml
模型文件：Msg.java,User.java
适配器:UserAdapter
子布局文件:user_item.xml

第一步修改.gradle文件，添加以下内容

    implementation 'com.squareup.okhttp3:okhttp:3.8.1'
    implementation 'com.squareup.okhttp3:mockwebserver:3.8.1'

    implementation 'com.alibaba:fastjson:1.2.10'
    implementation 'com.android.support:recyclerview-v7:28.0.0'

第二步，修改AndroidManifest.xml文件，添加以下内容

 <activity android:name=".ChatActivity">
 </activity>
 <activity android:name=".LoginActivity">
     <intent-filter>
         <action android:name="android.intent.action.MAIN" />

         <category android:name="android.intent.category.LAUNCHER"/>
     </intent-filter>
 </activity>

以及添加这行，注意添加的位置的区别

<uses-permission android:name="android.permission.INTERNET" />

第三步具体功能代码

LoginActivity.java

public class LoginActivity extends Activity {
    private EditText mEditTextName,mEditTextId;
    private Button mButtonLogin;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_login);
        init();

        mButtonLogin.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String userName = mEditTextName.getText().toString();
                String userId = mEditTextId.getText().toString();
                User user = new User(userId,userName);
                Intent intent = ChatActivity.newIntent(LoginActivity.this,user.toString());
                startActivity(intent);
                LoginActivity.this.finish();
            }
        });
    }

    private void init(){
        mEditTextName = findViewById(R.id.nickname_editText);
        mEditTextId = findViewById(R.id.id_editText);
        mEditTextName.setCompoundDrawables(initDrawable(R.drawable.nickname),null,null,null);
        mEditTextId.setCompoundDrawables(initDrawable(R.drawable.id),null,null,null);
        mButtonLogin = findViewById(R.id.login);
    }

    /**
     * 设置EditText左边图片的大小
     * */
    private Drawable initDrawable(int res){
        Drawable drawable = getResources().getDrawable(res);
        //距离左边距离，距离上边距离，长，宽
        drawable.setBounds(0,0,100,100);
        return drawable;
    }
}

activity_login.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@drawable/background">

    <!--    https://www.runoob.com/w3cnote/android-tutorial-relativelayout.html-->

    <RelativeLayout
        android:id="@+id/viewTop"
        android:layout_width="match_parent"
        android:layout_height="240dp"
        android:background="@color/mihuang">

        <ImageView
            android:layout_width="90dp"
            android:layout_height="90dp"
            android:layout_alignParentBottom="true"
            android:layout_centerHorizontal="true"
            android:layout_marginBottom="10dp"
            android:src="@drawable/boy" />
    </RelativeLayout>

    <RelativeLayout
        android:id="@+id/viewCenter"
        android:paddingTop="20dp"
        android:layout_centerHorizontal="true"
        android:layout_width="280dp"
        android:layout_height="wrap_content"
        android:layout_below="@+id/viewTop"
        android:paddingBottom="70dp">

        <EditText
            android:id="@+id/id_editText"
            android:layout_width="match_parent"
            android:layout_height="60dp"
            android:drawablePadding="10dp"
            android:drawableLeft="@drawable/id"
            android:hint="请输入Id"
            android:textSize="16sp"
            android:layout_marginLeft="10dp"/>

        <ImageView
            android:layout_width="40dp"
            android:layout_height="40dp"
            android:layout_alignParentRight="true"
            android:src="@drawable/down"
            android:paddingRight="10dp"
            android:paddingTop="20dp"/>

        <EditText
            android:layout_below="@+id/id_editText"
            android:id="@+id/nickname_editText"
            android:layout_width="match_parent"
            android:layout_height="60dp"
            android:drawablePadding="10dp"
            android:drawableLeft="@drawable/nickname"
            android:hint="请输入昵称"
            android:layout_marginLeft="10dp"
            android:textSize="16sp"/>

    </RelativeLayout>

    <Button
        android:layout_below="@+id/viewCenter"
        android:layout_centerHorizontal="true"
        android:id="@+id/login"
        android:layout_width="200dp"
        android:layout_height="wrap_content"
        android:layout_marginLeft="10dp"
        android:layout_marginRight="10dp"
        android:text="登陆"
        android:textColor="@color/text"
        android:background="@color/login"
        android:textSize="25dp" />

    <RelativeLayout
        android:layout_alignParentBottom="true"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:paddingBottom="10dp">
        <TextView
            android:text="无法登陆？"
            android:paddingLeft="10dp"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"/>
        <TextView
            android:text="新用户注册"
            android:paddingRight="10dp"
            android:layout_alignParentRight="true"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"/>
    </RelativeLayout>

</RelativeLayout>

ChatActivity.java

public class ChatActivity extends Activity {
    private ArrayList<User> mUserArrayList = new ArrayList<>();//定义一个存储信息的列表
    private EditText mInputText;//输入框
    private Button mSend;//发送按钮
    private RecyclerView mRecyclerView;//滑动框
    private UserAdapter mAdapter;//适配器
    private boolean backFlag = false;
    private WebSocket mSocket;


    private User mUser;;//全局User

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_chat);
        initView();

        String data = getIntent().getStringExtra("data");
        if (!data.equals("")){
            mUser = JSON.parseObject(data,User.class);
        }else {
            mUser = new User("0001","测试名字",R.drawable.boy);
        }


        LinearLayoutManager layoutManager = new LinearLayoutManager(this);
        mRecyclerView.setLayoutManager(layoutManager);
        mAdapter = new UserAdapter(mUserArrayList);
        mRecyclerView.setAdapter(mAdapter);

        //开启连接
        start(mUser.getUserId());

        mSend.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String content = mInputText.getText().toString();
                if (!"".equals(content)) {
                    Msg msg = new Msg(true,content,false);
                    User tempUser = new User(mUser.getUserId(),mUser.getUserName(),R.drawable.boy,msg);
                    mSocket.send(tempUser.toString());
                    mUserArrayList.add(tempUser);
                    updateRecyclerView();//刷新RecyclerView
                    //清空输入栏
                    mInputText.setText("");
                }
            }
        });

    }

    /**
     * 刷新view
     * */
    private void updateRecyclerView(){
        //当有新消息时，刷新RecyclerView中的显示
        mAdapter.notifyItemInserted(mUserArrayList.size() - 1);
        //将RecyclerView定位到最后一行
        mRecyclerView.scrollToPosition(mUserArrayList.size() - 1);
    }

    /**
     * 开启web socket连接
     * */
    private void start(String userId) {

        OkHttpClient mOkHttpClient = new OkHttpClient.Builder()
                .readTimeout(300, TimeUnit.SECONDS)//设置读取超时时间
                .writeTimeout(300, TimeUnit.SECONDS)//设置写的超时时间
                .connectTimeout(300, TimeUnit.SECONDS)//设置连接超时时间
                .build();

        //定义request
        Request request = new Request.Builder().url("ws://192.168.5.10:8080/test/"+userId).build();
        //绑定回调接口
        mOkHttpClient.newWebSocket(request, new EchoWebSocketListener());
        mOkHttpClient.dispatcher().executorService().shutdown();

    }

    /**
     * 显示内容
     * */
    private void output(final User user) {
        runOnUiThread(new Runnable() {
            @Override
            public void run() {
                mUserArrayList.add(user);
                updateRecyclerView();
            }
        });
    }

    /**
     * 初始化界面
     * */
    private void initView(){
        mInputText = findViewById(R.id.input_text);
        mSend = findViewById(R.id.send);
        mRecyclerView = findViewById(R.id.msg_recycler_view);
    }

    /**
     * 静态方法返回一个能启动自己的intent
     * */
    public static Intent newIntent(Context context,String data){
        Intent intent = new Intent(context,ChatActivity.class);
        intent.putExtra("data",data);
        return intent;
    }

    /**
     * 对返回键的处理
     * */
    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event){
        if(keyCode==KeyEvent.KEYCODE_BACK&&!backFlag){
            Toast.makeText(ChatActivity.this,"再按一次退出程序",Toast.LENGTH_SHORT).show();
            backFlag = true;
            return true;
        }else {
            return super.onKeyDown(keyCode, event);
        }
    }

    /**
     * 内部类，监听web socket回调
     * */
    private final class EchoWebSocketListener extends WebSocketListener {

        @Override
        public void onOpen(WebSocket webSocket, Response response) {
            super.onOpen(webSocket, response);
            mSocket = webSocket;    //实例化web socket
            User user = new User();
            user.setUserMsg(new Msg(false,"连接成功",true));
            output(user);
        }

        @Override
        public void onMessage(WebSocket webSocket, String text) {
            super.onMessage(webSocket, text);
            User user = JSON.parseObject(text, User.class);
            output(user);
        }

        @Override
        public void onClosed(WebSocket webSocket, int code, String reason) {
            super.onClosed(webSocket, code, reason);
            User user = new User();
            user.setUserMsg(new Msg(false,"关闭连接",true));
            output(user);
        }

        @Override
        public void onFailure(WebSocket webSocket, Throwable t, Response response) {
            super.onFailure(webSocket, t, response);
            User user = new User();
            user.setUserMsg(new Msg(false,"连接失败:"+t.getMessage(),true));
            output(user);
        }
    }

}

activity_chat.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#d8e0e8">

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/msg_recycler_view"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1" />

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
        <EditText
            android:id="@+id/input_text"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:maxLines="2"
            android:hint="请输入……"
            />
        <Button
            android:id="@+id/send"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="发送"/>
    </LinearLayout>
</LinearLayout>

Msg.java

public class Msg {
    private boolean send;//是否是发送的消息
    private String content;//发送的内容
    private boolean system;//是否是系统消息

    public Msg(boolean send, String content) {
        this.send = send;
        this.content = content;
        this.system = false;
    }

    public Msg() {
    }

    public Msg(boolean send, String content, boolean system) {
        this.send = send;
        this.content = content;
        this.system = system;
    }

    public boolean isSystem() {
        return system;
    }

    public void setSystem(boolean system) {
        this.system = system;
    }



    public boolean isSend() {
        return send;
    }

    public void setSend(boolean send) {
        this.send = send;
    }

    public String getContent() {
        return content;
    }

    public void setContent(String content) {
        this.content = content;
    }

    @Override
    public String toString() {
        return JSON.toJSONString(this);
    }
}

User.java

public class User {
    private String userId;
    private String userName;
    private int userImg;
    private Msg userMsg;

    public int getUserImg() {
        return userImg;
    }

    public void setUserImg(int userImg) {
        this.userImg = userImg;
    }

    public User(String userId, String userName, int userImg) {
        this.userId = userId;
        this.userName = userName;
        this.userImg = userImg;
    }

    public User() {
    }

    public User(String userId, String userName) {
        this.userId = userId;
        this.userName = userName;
    }

    public User(String userId, String userName, Msg userMsg) {
        this.userId = userId;
        this.userName = userName;
        this.userMsg = userMsg;
    }

    public User(String userId, String userName, int userImg, Msg userMsg) {
        this.userId = userId;
        this.userName = userName;
        this.userImg = userImg;
        this.userMsg = userMsg;
    }

    public String getUserId() {
        return userId;
    }

    public void setUserId(String userId) {
        this.userId = userId;
    }

    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName;
    }

    public Msg getUserMsg() {
        return userMsg;
    }

    public void setUserMsg(Msg userMsg) {
        this.userMsg = userMsg;
    }

    @Override
    public String toString() {
        return JSON.toJSONString(this);
    }
}

UserAdapter.java

public class UserAdapter extends RecyclerView.Adapter<UserAdapter.ViewHolder>{

    private ArrayList<User> mUsers;

    public UserAdapter(ArrayList<User> users) {
        mUsers = users;
    }

    @NonNull
    @Override
    public UserAdapter.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext())
                .inflate(R.layout.user_item,parent,false);

        return new ViewHolder(view);
    }

    @Override
    public void onBindViewHolder(@NonNull UserAdapter.ViewHolder holder, int position) {
        User user = mUsers.get(position);
        if (user.getUserMsg().isSystem()){//系统消息
            holder.mLinearLayoutSystem.setVisibility(View.VISIBLE);
            holder.mRelativeLayoutReceive.setVisibility(View.GONE);
            holder.mRelativeLayoutSend.setVisibility(View.GONE);
            holder.mTextViewSystemText.setText(user.getUserMsg().getContent());
        }else{
            if (user.getUserMsg().isSend()){//是发送消息
                holder.mLinearLayoutSystem.setVisibility(View.GONE);
                holder.mRelativeLayoutReceive.setVisibility(View.GONE);
                holder.mRelativeLayoutSend.setVisibility(View.VISIBLE);

                holder.mImageViewSend.setImageResource(user.getUserImg());
                holder.mTextViewNameSend.setText(user.getUserName());
                holder.mTextViewContentSend.setText(user.getUserMsg().getContent());
            }else { //接收的消息
                holder.mLinearLayoutSystem.setVisibility(View.GONE);
                holder.mRelativeLayoutReceive.setVisibility(View.VISIBLE);
                holder.mRelativeLayoutSend.setVisibility(View.GONE);

                holder.mImageViewReceive.setImageResource(user.getUserImg());
                holder.mTextViewNameReceive.setText(user.getUserName());
                holder.mTextViewContentReceive.setText(user.getUserMsg().getContent());
            }
        }

    }

    @Override
    public int getItemCount() {
        return mUsers.size();
    }

    public class ViewHolder extends RecyclerView.ViewHolder {
        //绑定所有视图
        RelativeLayout mRelativeLayoutSend,mRelativeLayoutReceive;
        LinearLayout mLinearLayoutSystem;
        ImageView mImageViewReceive,mImageViewSend;
        TextView mTextViewNameReceive,mTextViewNameSend,mTextViewContentReceive,mTextViewContentSend,mTextViewSystemText;

        public ViewHolder(@NonNull View itemView) {
            super(itemView);
            mRelativeLayoutReceive = itemView.findViewById(R.id.receive_relative);
            mRelativeLayoutSend = itemView.findViewById(R.id.send_relative);
            mLinearLayoutSystem = itemView.findViewById(R.id.system_layout);

            mImageViewReceive = itemView.findViewById(R.id.image_receive);
            mImageViewSend = itemView.findViewById(R.id.image_send);

            mTextViewNameReceive = itemView.findViewById(R.id.text_name_receive);
            mTextViewNameSend = itemView.findViewById(R.id.text_name_send);
            mTextViewContentReceive = itemView.findViewById(R.id.text_content_receive);
            mTextViewContentSend = itemView.findViewById(R.id.text_content_send);
            mTextViewSystemText = itemView.findViewById(R.id.system_text);
        }
    }
}

user_item.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent" android:layout_height="wrap_content"
    android:layout_marginBottom="10dp">
    <RelativeLayout
        android:id="@+id/receive_relative"
        android:orientation="vertical"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
        <ImageView
            android:layout_alignParentLeft="true"
            android:id="@+id/image_receive"
            android:layout_width="60dp"
            android:layout_height="60dp"
            android:layout_marginTop="20dp"
            android:layout_marginLeft="10dp"
            android:src="@drawable/boy"/>
        <LinearLayout
            android:layout_toRightOf="@id/image_receive"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:orientation="vertical">
            <TextView
                android:id="@+id/text_name_receive"
                android:layout_width="50dp"
                android:layout_height="20dp"
                android:layout_gravity="left"
                android:text="大青儿"
                android:textSize="15dp"
                android:textColor="#131313"
                android:layout_marginLeft="20dp"/>
            <LinearLayout
                android:id="@+id/layout_content_receive"
                android:layout_gravity="right"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:background="@drawable/message_left">
                <TextView
                    android:id="@+id/text_content_receive"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_gravity="center"
                    android:layout_margin="5dp"
                    android:textSize="20dp"
                    android:textColor="#F5EFEF"
                    android:text="我是一段文字一段文"
                    />
            </LinearLayout>
        </LinearLayout>
    </RelativeLayout>
    <RelativeLayout
        android:id="@+id/send_relative"
        android:orientation="vertical"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
        <ImageView
            android:layout_alignParentRight="true"
            android:id="@+id/image_send"
            android:layout_width="60dp"
            android:layout_height="60dp"
            android:layout_marginTop="20dp"
            android:layout_marginRight="10dp"
            android:src="@drawable/boy"/>
        <LinearLayout
            android:layout_toLeftOf="@id/image_send"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:orientation="vertical">
            <TextView
                android:id="@+id/text_name_send"
                android:layout_width="50dp"
                android:layout_height="20dp"
                android:layout_gravity="right"
                android:text="大青儿"
                android:textSize="15dp"
                android:textColor="#131313"
                android:layout_marginRight="20dp"/>

            <LinearLayout
                android:id="@+id/layout_content_send"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_gravity="right"
                android:background="@drawable/message_right">

                <TextView
                    android:id="@+id/text_content_send"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_gravity="center"
                    android:layout_margin="5dp"
                    android:text="我是一段文字一段文"
                    android:textSize="20dp" />
            </LinearLayout>
        </LinearLayout>
    </RelativeLayout>

    <LinearLayout
        android:id="@+id/system_layout"
        android:orientation="vertical"
        android:layout_width="match_parent"
        android:layout_height="match_parent">
        <TextView
            android:id="@+id/system_text"
            android:layout_width="wrap_content"
            android:layout_height="20dp"
            android:text="系统消息:"
            android:layout_gravity="center"
            android:textColor="#F17070"/>
    </LinearLayout>
</RelativeLayout>

图片资源

应用中大部分图片资源都是只起装饰性作用，可以在阿里巴巴矢量图标库获取，当然包裹聊天文字的图片是.9格式图片，可以参考：Android Studio制作.9图片

提醒一哈

先配置好后端再进行前端测试，不然没连上服务器会报错并闪退。因为当你点发送的时候，有一段代码中websocket并没有被实例化。