Socket是TCP/IP协议上的一种通信，在通信的两端各建立一个Socket，从而在通信的两端之间形成网络虚拟链路。一旦建立了虚拟的网络链路，两端的程序就可以通过虚拟链路进行通信。
Client A 发信息给 Client B , A的信息首先发送信息到服务器Server ，Server接受到信息后再把A的信息广播发送给所有的Clients
首先我们要在服务器建立一个ServerSocket ，ServerSocket对象用于监听来自客户端的Socket连接，如果没有连接，它将一直处于等待状态。
Socket accept()：如果接收到一个客户端Socket的连接请求，该方法将返回一个与客户端Socket对应的Socket
Server示例：
//创建一个ServerSocket，用于监听客户端Socket的连接请求 ServerSocket ss = new ServerSocket(30000); //采用循环不断接受来自客户端的请求 while (true){ //每当接受到客户端Socket的请求，服务器端也对应产生一个Socket Socket s = ss.accept(); //下面就可以使用Socket进行通信了 ... }
客户端通常可使用Socket的构造器来连接到指定服务器
Client示例:
//创建连接到服务器、30000端口的Socket Socket s = new Socket("192.168.2.214" , 30000); //下面就可以使用Socket进行通信了 ...
这样Server和Client就可以进行一个简单的通信了
当然，我们要做的是多客户，所以每当客户端Socket连接到该ServerSocket之后，程序将对应Socket加入clients集合中保存，并为该Socket启动一条线程，该线程负责处理该Socket所有的通信任务
//定义保存所有Socket的ArrayList public static ArrayList<Socket> clients = new ArrayList<Socket>();
当服务器线程读到客户端数据之后，程序遍历clients集合，并将该数据向clients集合中的每个Socket发送一次。这样就可以实现一个聊天室的功能了
下面来看看整个功能的demo
先建立一个Java工程，把Server.java运行起来，然后再运行手机模拟器
服务器打印信息：
程序文件结构：
1.先看看主Activity : SocketmsgActivity.java
public class SocketmsgActivity extends Activity { /** Called when the activity is first created. */ private SQLiteDatabase db; Thread thread = null; Socket s = null; private InetSocketAddress isa = null; DataInputStream dis = null; DataOutputStream dos = null; private String reMsg=null; private Boolean isContect = false; private EditText chattxt; private EditText chatbox; private Button chatok; private String chatKey="SLEEKNETGEOCK4stsjeS"; private String name=null,ip=null,port=null; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); chattxt = (EditText)findViewById(R.id.chattxt); chatbox = (EditText)findViewById(R.id.chatbox); chatok = (Button)findViewById(R.id.chatOk); chatbox.setCursorVisible(false); chatbox.setFocusable(false); chatbox.setFocusableInTouchMode(false); chatbox.setGravity(2); //初始化，创建数据库来储存用户信息 InitDatabase(); db = SQLiteDatabase.openOrCreateDatabase(config.f, null); try { Cursor cursor = db.query("config", new String[]{"ip","name","port"},null,null, null, null, null); while(cursor.moveToNext()){ name = cursor.getString(cursor.getColumnIndex("name")); ip = cursor.getString(cursor.getColumnIndex("ip")); port = cursor.getString(cursor.getColumnIndex("port")); } cursor.close(); } catch (Exception e) { // TODO: handle exception System.out.println(e.toString()); } db.close(); //设置连接 if(ip==null || port==null){ Intent intent = new Intent(SocketmsgActivity.this,IniActivity.class); startActivity(intent); SocketmsgActivity.this.finish(); } //设置名称 else if(name==null){ Intent intent = new Intent(SocketmsgActivity.this,IniuserActivity.class); startActivity(intent); SocketmsgActivity.this.finish(); }else{ connect(); chatok.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { String str = chattxt.getText().toString().trim(); System.out.println(s); try { dos.writeUTF(chatKey+"name:"+name+"end;"+str); chattxt.setText(""); }catch (SocketTimeoutException e) { System.out.println("連接超時，服務器未開啟或IP錯誤"); Toast.makeText(SocketmsgActivity.this, "連接超時，服務器未開啟或IP錯誤", Toast.LENGTH_SHORT).show(); Intent intent = new Intent(SocketmsgActivity.this,IniActivity.class); startActivity(intent); SocketmsgActivity.this.finish(); e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block System.out.println("連接超時，服務器未開啟或IP錯誤"); Toast.makeText(SocketmsgActivity.this, "連接超時，服務器未開啟或IP錯誤", Toast.LENGTH_SHORT).show(); Intent intent = new Intent(SocketmsgActivity.this,IniActivity.class); startActivity(intent); SocketmsgActivity.this.finish(); e.printStackTrace(); } } }); } } private Runnable doThread = new Runnable() { public void run() { System.out.println("running!"); ReceiveMsg(); } }; public void connect() { try { s = new Socket(); isa = new InetSocketAddress(ip,Integer.parseInt(port)); s.connect(isa,5000); if(s.isConnected()){ dos = new DataOutputStream (s.getOutputStream()); dis = new DataInputStream (s.getInputStream()); dos.writeUTF(chatKey+"online:"+name); /** * 这里是关键，我在此耗时8h+ * 原因是 子线程不能直接更新UI * 为此，我们需要通过Handler物件，通知主线程Ui Thread来更新界面。 * */ thread = new Thread(null, doThread, "Message"); thread.start(); System.out.println("connect"); isContect=true; } }catch (UnknownHostException e) { System.out.println("連接失敗"); Toast.makeText(SocketmsgActivity.this, "連接失敗", Toast.LENGTH_SHORT).show(); Intent intent = new Intent(SocketmsgActivity.this,IniActivity.class); startActivity(intent); SocketmsgActivity.this.finish(); e.printStackTrace(); }catch (SocketTimeoutException e) { System.out.println("連接超時，服務器未開啟或IP錯誤"); Toast.makeText(SocketmsgActivity.this, "連接超時，服務器未開啟或IP錯誤", Toast.LENGTH_SHORT).show(); Intent intent = new Intent(SocketmsgActivity.this,IniActivity.class); startActivity(intent); SocketmsgActivity.this.finish(); e.printStackTrace(); }catch (IOException e) { System.out.println("連接失敗"); e.printStackTrace(); } } public void disConnect() { if(dos!=null){ try { dos.writeUTF(chatKey+"offline:"+name); } catch (IOException e1) { // TODO Auto-generated catch block e1.printStackTrace(); } try { s.close(); } catch (IOException e) { e.printStackTrace(); } } } /** * 线程监视Server信息 */ private void ReceiveMsg() { if (isContect) { try { while ((reMsg = dis.readUTF()) != null) { System.out.println(reMsg); if (reMsg != null) { try { Message msgMessage = new Message(); msgMessage.what = 0x1981; handler.sendMessage(msgMessage); Thread.sleep(100); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } } catch (SocketException e) { // TODO: handle exception System.out.println("exit!"); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } /** * 通过handler更新UI */ Handler handler = new Handler() { public void handleMessage(Message msg) { switch (msg.what) { case 0x1981: chatbox.setText(chatbox.getText() + reMsg + 'n'); chatbox.setSelection(chatbox.length()); break; } } }; @Override protected void onDestroy() { // TODO Auto-generated method stub super.onDestroy(); disConnect(); //System.exit(0); } @Override public boolean onCreateOptionsMenu(Menu menu) { // TODO Auto-generated method stub menu.add(0, 1, 1, "初始化設置"); menu.add(0, 2, 2, "退出"); return super.onCreateOptionsMenu(menu); } @Override public boolean onOptionsItemSelected(MenuItem item) { // TODO Auto-generated method stub if(item.getItemId()==1){ Intent intent = new Intent(SocketmsgActivity.this,IniActivity.class); startActivity(intent); SocketmsgActivity.this.finish(); }else if(item.getItemId()==2){ disConnect(); SocketmsgActivity.this.finish(); android.os.Process.killProcess(android.os.Process.myPid()); System.exit(0); } return super.onOptionsItemSelected(item); } public void InitDatabase(){ if(!config.path.exists()){ config.path.mkdirs(); Log.i("LogDemo", "mkdir"); } if(!config.f.exists()){ try{ config.f.createNewFile(); Log.i("LogDemo", "create a new database file"); }catch(IOException e){ Log.i("LogDemo",e.toString()); } } try { if(tabIsExist("config")==false){ db = SQLiteDatabase.openOrCreateDatabase(config.f, null); db.execSQL("create table config(_id integer primary key autoincrement," + "ip varchar(128),port varchar(10),name varchar(32))"); Log.i("LogDemo", "create a database"); db.close(); } } catch (Exception e) { // TODO: handle exception Log.i("LogDemo",e.toString()); } } /** * check the database is already exist * @param tabName * @return */ public boolean tabIsExist(String tabName){ boolean result = false; if(tabName == null){ return false; } Cursor cursor = null; db = SQLiteDatabase.openOrCreateDatabase(config.f, null); try { String sql = "select count(*) as c from sqlite_master where type ='table' " + "and name ='"+tabName.trim()+"' "; cursor = db.rawQuery(sql, null); if(cursor.moveToNext()){ int count = cursor.getInt(0); if(count>0){ result = true; } } } catch (Exception e) { // TODO: handle exception } cursor.close(); db.close(); return result; } }
2.初始化IP和端口Activity， IniActivity.java
public class IniActivity extends Activity{ private EditText ip,port; private Button nextButton; private String getip,getport; private ProgressDialog progressDialog; private InetSocketAddress isa = null; private SQLiteDatabase db; private String ipstring=null,portString=null; private int row=0; @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); setContentView(R.layout.config); ip = (EditText)findViewById(R.id.ip); port = (EditText)findViewById(R.id.port); nextButton = (Button)findViewById(R.id.next); db = SQLiteDatabase.openOrCreateDatabase(config.f, null); try { Cursor cursor = db.query("config", new String[]{"ip","port"},null,null, null, null, null); while(cursor.moveToNext()){ ipstring = cursor.getString(cursor.getColumnIndex("ip")); portString = cursor.getString(cursor.getColumnIndex("port")); row++; } ip.setText(ipstring); port.setText(portString); cursor.close(); } catch (Exception e) { // TODO: handle exception System.out.println(e.toString()); } db.close(); nextButton.setOnClickListener(new nextButtonListenner()); } class nextButtonListenner implements OnClickListener{ @Override public void onClick(View v) { // TODO Auto-generated method stub getip = ip.getText().toString().trim(); getport = port.getText().toString().trim(); if(getip=="" || getip==null || getip.equals("")){ Toast.makeText(IniActivity.this, "請輸入IP", Toast.LENGTH_SHORT).show(); ip.setFocusable(true); }else if(getport=="" || getport==null || getport.equals("")){ Toast.makeText(IniActivity.this, "請輸入端口", Toast.LENGTH_SHORT).show(); port.setFocusable(true); }else{ //progressDialog = ProgressDialog.show(IniActivity.this, "", "請稍後...", true, false); //new Thread() { //@Override //public void run() { try { Socket s = new Socket(); isa = new InetSocketAddress(getip,Integer.parseInt(getport)); s.connect(isa,5000); //showDialog("連接成功",IniActivity.this); try { //生成ContentValues对象 ContentValues values = new ContentValues(); //想该对象当中插入键值对，其中键是列名，值是希望插入到这一列的值，值必须和数据库当中的数据类型一致 values.put("ip", getip); values.put("port",getport); db = SQLiteDatabase.openOrCreateDatabase(config.f, null); if(row==0){ db.insert("config", null, values); }else{ db.update("config", values ,null,null); } Toast.makeText(IniActivity.this, "連接成功", Toast.LENGTH_SHORT); s.close(); Intent intent = new Intent(IniActivity.this,IniuserActivity.class); startActivity(intent); IniActivity.this.finish(); db.close(); } catch (Exception e) { // TODO: handle exception showDialog("設置失敗，數據庫不可用",IniActivity.this); } } catch (UnknownHostException e) { // TODO Auto-generated catch block e.printStackTrace(); showDialog("連接失敗，IP或者端口不可用",IniActivity.this); }catch (SocketTimeoutException e) { System.out.println("連接超時，服務器未開啟或IP錯誤"); showDialog("連接超時，服務器未開啟或IP錯誤",IniActivity.this); e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); showDialog("連接失敗，IP或者端口不可用",IniActivity.this); } //progressDialog.dismiss(); //finish(); //} //}.start(); } } } /** * define a dialog for show the message * @param mess * @param activity */ public void showDialog(String mess,Activity activity){ new AlertDialog.Builder(activity).setTitle("信息") .setMessage(mess) .setNegativeButton("確定",new DialogInterface.OnClickListener() { public void onClick(DialogInterface dialog, int which) { } }) .show(); } }
3.初始化用户名称Activity， IniuserActivity.java
public class IniuserActivity extends Activity{ private EditText name; private Button ok; private SQLiteDatabase db; private String nameString; @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); setContentView(R.layout.configuser); name = (EditText)findViewById(R.id.name); ok = (Button)findViewById(R.id.ok); ok.setOnClickListener(new okButtonListenner()); db = SQLiteDatabase.openOrCreateDatabase(config.f, null); try { Cursor cursor = db.query("config", new String[]{"name"},null,null, null, null, null); while(cursor.moveToNext()){ nameString = cursor.getString(cursor.getColumnIndex("name")); } name.setText(nameString); cursor.close(); } catch (Exception e) { // TODO: handle exception System.out.println(e.toString()); } db.close(); } class okButtonListenner implements OnClickListener{ @Override public void onClick(View v) { // TODO Auto-generated method stub String getname = name.getText().toString().trim(); if(getname==""){ Toast.makeText(IniuserActivity.this, "請輸入您的稱呢", Toast.LENGTH_SHORT).show(); name.setFocusable(true); }else{ try { //生成ContentValues对象 ContentValues values = new ContentValues(); //想该对象当中插入键值对，其中键是列名，值是希望插入到这一列的值，值必须和数据库当中的数据类型一致 values.put("name", getname); db = SQLiteDatabase.openOrCreateDatabase(config.f, null); db.update("config",values,null,null); Toast.makeText(IniuserActivity.this, "設置完成", Toast.LENGTH_SHORT).show(); Intent intent = new Intent(IniuserActivity.this,SocketmsgActivity.class); startActivity(intent); IniuserActivity.this.finish(); db.close(); } catch (Exception e) { // TODO: handle exception showDialog("設置失敗，數據庫不可用",IniuserActivity.this); } } } } /** * define a dialog for show the message * @param mess * @param activity */ public void showDialog(String mess,Activity activity){ new AlertDialog.Builder(activity).setTitle("信息") .setMessage(mess) .setNegativeButton("確定",new DialogInterface.OnClickListener() { public void onClick(DialogInterface dialog, int which) { } }) .show(); } }
4.config.java
public class config{ public static String SDCARD = android.os.Environment.getExternalStorageDirectory().getAbsolutePath(); public static File path = new File(SDCARD+"/RunChatDatabase/"); //数据库文件目录 public static File f = new File(SDCARD+"/RunChatDatabase/config.db"); //数据库文件 }
布局文件：
1.main.xml
<"1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent"> <EditText android:id="@+id/chatbox" android:layout_width="fill_parent" android:layout_height="fill_parent" android:layout_weight="1"> </EditText> <EditText android:id="@+id/chattxt" android:layout_width="fill_parent" android:layout_height="wrap_content" android:gravity="top" android:hint="你想和对方说点什么？"> </EditText> <Button android:id="@+id/chatOk" android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="Send" android:textSize="@dimen/btn1"> </Button> </LinearLayout>
2.config.xml
<"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"> <TextView android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="初始化設置" android:textSize="@dimen/h2"/> <TextView android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="服務器IP" android:textSize="@dimen/h3"/> <EditText android:layout_width="fill_parent" android:layout_height="wrap_content" android:hint="192.168.2.214" android:id="@+id/ip" android:textSize="@dimen/et1"/> <TextView android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="端口" android:textSize="@dimen/h3"/> <EditText android:layout_width="fill_parent" android:layout_height="wrap_content" android:hint="8888" android:id="@+id/port" android:textSize="@dimen/et1"/> <Button android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="下一步" android:id="@+id/next" android:textSize="@dimen/btn1"/> </LinearLayout>
3.configuer.xml
<"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"> <TextView android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="初始化設置" android:textSize="@dimen/h2"/> <TextView android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="您的稱呢" android:textSize="@dimen/h3"/> <EditText android:layout_width="fill_parent" android:layout_height="wrap_content" android:hint="潤仔" android:id="@+id/name" android:maxLength="20" android:textSize="@dimen/et1"/> <Button android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="完成" android:id="@+id/ok" android:textSize="@dimen/btn1"/> </LinearLayout> style文件：dimens.xml <"1.0" encoding="utf-8"?> <resources> <dimen name="h3">30dip</dimen> <dimen name="h2">40dip</dimen> <dimen name="btn1">30dip</dimen> <dimen name="et1">25dip</dimen> </resources>
最后是服务器文件：Server.java
import java.io.*; import java.net.*; import java.text.DateFormat; import java.text.SimpleDateFormat; import java.util.*; import javax.sound.sampled.Port; import javax.swing.JOptionPane; public class Server { ServerSocket ss = null; private String getnameString=null; boolean started = false; List<Client> clients = new ArrayList<Client>(); List<Info> infos = new ArrayList<Info>(); public static void main(String[] args) { String inputport = JOptionPane.showInputDialog("請輸入該服務器使用的端口:"); int port = Integer.parseInt(inputport); new Server().start(port); } public void start(int port) { try { ss = new ServerSocket(port); System.out.println("服務器啟動"); started = true; } catch (BindException e) { System.out.println(" 端口已经被占用"); System.exit(0); } catch (IOException e) { e.printStackTrace(); } try { while (started) { Socket s = ss.accept(); Client c = new Client (s); System.out.println("a client is connected"); new Thread(c).start(); clients.add(c); } } catch (IOException e) { e.printStackTrace(); } finally { try { ss.close(); } catch (IOException e) { e.printStackTrace(); } } } public List<Client> getClient(){ return clients; } class Client implements Runnable { private String chatKey="SLEEKNETGEOCK4stsjeS"; private Socket s = null; private DataInputStream dis = null; private DataOutputStream dos = null; private boolean bConnected = false; private String sendmsg=null; Client (Socket s) { this.s = s; try { dis = new DataInputStream (s.getInputStream()); dos = new DataOutputStream (s.getOutputStream()); bConnected = true; } catch(IOException e) { e.printStackTrace(); } } public void send (String str) { try { //System.out.println(s); dos.writeUTF(str+""); dos.flush(); } catch(IOException e) { clients.remove(this); System.out.println("对方已经退出了"); } } public void run() { try { while (bConnected) { String str = dis.readUTF(); DateFormat df = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss"); String date = " ["+df.format(new Date())+"]"; if(str.startsWith(chatKey+"online:")){ Info info = new Info(); getnameString = str.substring(27); info.setName(getnameString); infos.add(info); for (int i=0; i<clients.size(); i++) { Client c = clients.get(i); c.send(getnameString+" on line."+date); } System.out.println(getnameString+" on line."+date); }else if(str.startsWith(chatKey+"offline:")){ getnameString = str.substring(28); clients.remove(this); for (int i=0; i<clients.size(); i++) { Client c = clients.get(i); c.send(getnameString+" off line."+date); } System.out.println(getnameString+" off line."+date); } else{ int charend = str.indexOf("end;"); String chatString = str.substring(charend+4); String chatName = str.substring(25, charend); sendmsg=chatName+date+"n"+chatString; for (int i=0; i<clients.size(); i++) { Client c = clients.get(i); c.send(sendmsg); } System.out.println(sendmsg); } } } catch (SocketException e) { System.out.println("client is closed!"); clients.remove(this); } catch (EOFException e) { System.out.println("client is closed!"); clients.remove(this); } catch (IOException e) { e.printStackTrace(); } finally { try { if (dis != null) dis.close(); if (dos != null) dos.close(); if (s != null) s.close(); } catch (IOException e) { e.printStackTrace(); } } } } class Info{ private String info_name = null; public Info(){ } public void setName(String name){ info_name = name; } public String getName(){ return info_name; } } }
以上只是一个粗略的聊天室功能，如果要实现私聊，还需要保存该Socket关联的客户信息。一个客户端可以将信息发送另一个指定客户端。实际上，我们知道所有客户端只与服务器连接，客户端之间并没有互相连接。这个功能等我以后有时间再写个demo.....
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持查字典教程网。