1、使用Socket進行兩個手機之間的通訊需要安裝兩個不同的程式碼檔案：服務端和客戶端   分別進行安裝

2、建立區域網：兩個手機同時連一個WiFi或者兩個手機進行熱點和WLAN連線

3、客戶端連線另一個手機IP時把另一個手機的IP改成靜態IP（3的第二種方法做這個步驟）

下面上程式碼分客戶端的和服務端的，佈局檔案textview、Editview、Button不上程式碼了，不懂socket通訊原理的可以在百度百科上檢視

客戶端：

1）、MianSocketClient.java

public class MianSocketClient extends AppCompatActivity
 
{
private SocketClient client;
private TextView txt;
private EditText edit;
private Button btn;
@Override
protected void onCreate(@Nullable Bundle savedInstanceState)
    {
super.onCreate ( savedInstanceState );
setContentView ( R.layout.activity_main );
txt=(TextView)findViewById ( R.id.textView );
 
edit=(EditText)findViewById ( R.id.edit );
btn=(Button)findViewById ( R.id.btn );
client=new SocketClient ();
//服務端的IP地址和埠號
client.clintValue (this,"10.0.3.15" ,6666);
//開啟客戶端接收訊息執行緒
client.openClientThread ();
/**
         * 傳送訊息
* */
btn.setOnClickListener ( new View.OnClickListener ( )
        {
@Override
 
public void onClick(View v)
            {
client.sendMsg ( edit.getText ().toString () );
}
        } );
/**
         *  接受訊息
*
         **/
SocketClient.mHandler=new Handler (  ){
@Override
public void handleMessage(Message msg)
            {
txt.setText ( msg.obj.toString ());
Log.i ( "msghh",msg.obj.toString ());
}
        };
}
}

public class SocketClient
{
private Socket client;
private Context context;
private int port;           //IP
private String site;            //埠
private Thread thread;
public static Handler mHandler;
private boolean isClient=false;
private PrintWriter out;
private InputStream in;
private String str;
/**
     * @effect 開啟執行緒建立連線開啟客戶端
* */
public void openClientThread(){
thread=new Thread ( new Runnable ( )
        {
@Override
public void run()
            {
try {
/**
                     *  connect()步驟
* */
client=new Socket ( site,port );
//                    client.setSoTimeout ( 5000 );//設定超時時間
if (client!=null)
                    {
isClient=true;
forOut();
forIn ();
}else {
isClient=false;
Toast.makeText ( context,"網路連線失敗",Toast.LENGTH_LONG ).show ();
}
Log.i ( "hahah","site="+site+" ,port="+port );
}catch (UnknownHostException e) {
e.printStackTrace ();
Log.i ( "socket","6" );
}catch (IOException e) {
e.printStackTrace ();
Log.i ( "socket","7" );
}
            }
        } );
thread.start ();
}
/**
     * 呼叫時向類裡傳值
* */
public void clintValue(Context context,String site,int port)
    {
this.context=context;
this.site=site;
this.port=port;
}
/**
     * @effect 得到輸出字串
* */
public void forOut()
    {
try {
out=new PrintWriter ( client.getOutputStream () );
}catch (IOException e){
e.printStackTrace ();
Log.i ( "socket","8" );
}
    }
/**
     * @steps read();
     * @effect 得到輸入字串
* */
public void forIn(){
while (isClient) {
try {
in=client.getInputStream ();
/**得到的是16進位制數，需要進行解析*/
byte[] bt = new byte[50];
in.read ( bt );
str=new String ( bt,"UTF-8" );
} catch (IOException e) {}
if (str!=null) {
Message msg = new Message ( );
msg.obj =str ;
mHandler.sendMessage ( msg );
}
        }
    }
/**
     * @steps write();
     * @effect 傳送訊息
* */
public void sendMsg(final String str)
    {
new Thread ( new Runnable ( )
        {
@Override
public void run()
            {
if (client!=null)
                {
out.print ( str );
out.flush ();
Log.i ( "outtt",out+"" );
}else
{
isClient=false;
Toast.makeText ( context,"網路連線失敗",Toast.LENGTH_LONG ).show ();
}
            }
        } ).start ();
}
}

1）、MianActivity.java   之前取的名字沒有改 應該改成MainSocketServer.java

public class MainActivity extends AppCompatActivity
{
private TextView txt;
private EditText edit;
private Button btn;
/**啟動服務端埠
* 服務端IP為手機IP
     * */
private SocketServer server=new SocketServer ( 6666 );
@Override
protected void onCreate(Bundle savedInstanceState)
    {
super.onCreate ( savedInstanceState );
setContentView ( R.layout.activity_main );
txt = (TextView) findViewById ( R.id.textView );
edit = (EditText) findViewById ( R.id.edit );
btn = (Button) findViewById ( R.id.btn );
/**socket服務端開始監聽*/
server.beginListen ( );
btn.setOnClickListener ( new View.OnClickListener ( )
        {
@Override
public void onClick(View v)
            {
/**socket傳送資料*/
server.sendMessage ( edit.getText ().toString () );
}
        } );
/**socket收到訊息執行緒*/
SocketServer.ServerHandler=new Handler (  ){
@Override
public void handleMessage(Message msg)
            {
txt.setText ( msg.obj.toString ());
}
        };
}
}

public class SocketServer
{
private ServerSocket server;
private Socket socket;
private InputStream in;
private String str=null;
private boolean isClint=false;
public static Handler ServerHandler;
/**
     * @steps bind();繫結埠號
* @effect 初始化服務端
* @param port 埠號
* */
public SocketServer(int port){
try {
server= new ServerSocket ( port );
isClint=true;
}catch (IOException e){
e.printStackTrace ();
}
    }
/**
     * @steps listen();
     * @effect socket監聽資料
* */
public void beginListen()
    {
new Thread ( new Runnable ( )
        {
@Override
public void run()
            {
try {
/**
                     * accept();
                     * 接受請求
* */
socket=server.accept ();
try {
/**得到輸入流*/
in =socket.getInputStream();
/**
                         * 實現資料迴圈接收
* */
while (!socket.isClosed())
                        {
byte[] bt=new byte[50];
in.read ( bt );
str=new String ( bt,"UTF-8" );                  //編碼方式  解決收到資料亂碼
if (str!=null&&str!="exit")
                            {
returnMessage ( str );
}else if (str==null||str=="exit"){
break;                                     //跳出迴圈結束socket資料接收
}
System.out.println(str);
}
                    } catch (IOException e) {
e.printStackTrace ( );
socket.isClosed ();
}
                } catch (IOException e) {
e.printStackTrace ( );
socket.isClosed ();
}
            }
        } ).start ();
}
/**
     * @steps write();
     * @effect socket服務端傳送資訊
* */
public void sendMessage(final String chat)
    {
Thread thread=new Thread ( new Runnable ( )
        {
@Override
public void run()
            {
try {
PrintWriter out=new PrintWriter ( socket.getOutputStream () );
out.print ( chat );
out.flush ();
} catch (IOException e) {
e.printStackTrace ( );
}
            }
        } );
thread.start ();
}
/**
     * @steps read();
     * @effect socket服務端得到返回資料併發送到主介面
* */
public void returnMessage(String chat){
Message msg=new Message ();
msg.obj=chat;
ServerHandler.sendMessage ( msg );
}
}

實現了兩個真機的簡單通訊

之後動專案時候改完的新程式碼，可以兩個真機都可以裝這個一個軟體

下載地址：https://github.com/845774766/socket