socket编程java,socket编程c语言
java socket 编程 登录
给你一个聊天室的，这个是客户端之间的通信，服务器负责接收和转发，你所要的服务器与客户端对发，只要给服务器写个界面显示和输入就行，所有代码如下：
你测试的时候应该把所有代码放在同一个工程下，因为客户端可服务器共用同一个POJO，里面有些包的错误，删除掉就行了
服务器代码，即服务器入口程序：
import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.ObjectOutputStream;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Date;
import java.util.HashSet;
public class ChatRoomServer {
private ServerSocket ss;
private HashSetSocket allSockets;
private UserDao dao;
public ChatRoomServer(){
try {
ss=new ServerSocket(9999);
allSockets=new HashSetSocket();
dao=new UserDaoForTextFile(new File("d:/stu/user.txt"));
} catch (IOException e) {
e.printStackTrace();
}
}
public void startService() throws IOException{
while(true){
Socket s=ss.accept();
allSockets.add(s);
new ChatRoomServerThread(s).start();
}
}
class ChatRoomServerThread extends Thread{
private Socket s;
public ChatRoomServerThread(Socket s){
this.s=s;
}
public void run(){
//1,得到Socket的输入流，并包装。
//2，循环从输入流中读取一行数据。
//3，每读到一行数据，判断该行是否是退出命令？
//4，如果是退出命令，则将当前socket从集合中删除，关闭当前socket，并跳出循环
//5，如果不是退出命令，则将该消model.getCurrentUser().getName()息转发给所有在线的客户端。
// 循环遍历allSockets集合，得到每一个socket的输出流，向流中写出该消息。
BufferedReader br=null;
String str = null;
try {
br = new BufferedReader(new InputStreamReader(s
.getInputStream()));
while((str=br.readLine())!=null ){
if(str.indexOf("%EXIT%")==0){
allSockets.remove(s);
//向其他客户端发送XXX退出的消息
sendMessageToAllClient(str.split(":")[1]+"离开聊天室！");
s.close();
break;
}else if(str.indexOf("%LOGIN%")==0){
String userName=str.split(":")[1];
String password=str.split(":")[2];
User user=dao.getUser(userName, password);
ObjectOutputStream oos=new ObjectOutputStream(s.getOutputStream());
oos.writeObject(user);
oos.flush();
if(user!=null){
sendMessageToAllClient(user.getName()+"进入聊天室！");
}
str = null;
}
if(str!=null){
sendMessageToAllClient(str);
}
}
} catch (Exception e) {
e.printStackTrace();
}
}
public void sendMessageToAllClient(String message)throws IOException{
Date date=new Date();
System.out.println(s.getInetAddress()+":"+message+"\t["+date+"]");
for(Socket temps:allSockets){
PrintWriter pw=new PrintWriter(temps.getOutputStream());
pw.println(message+"\t["+date+"]");
pw.flush();
}
}
}
public static void main(String[] args) {
try {
new ChatRoomServer().startService();
} catch (IOException e) {
e.printStackTrace();
}
}
}
客户端代码：
总共4个：
1：入口程序：
public class ChatRoomClient {
private ClientModel model;
public ChatRoomClient(){
// String hostName = JOptionPane.showInputDialog(null,
// "请输入服务器主机名：");
// String portName = JOptionPane
// .showInputDialog(null, "请输入端口号：");
//固定服务端IP和端口
model=new ClientModel("127.0.0.1",Integer.parseInt("9999"));
model.createSocket();
new LoginFrame(model).showMe();
}
public static void main(String[] args) {
new ChatRoomClient();
}
}
2：登陆后显示界面：
import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.PrintWriter;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;
public class ClientMainFrame extends JFrame{
private JTextArea area;
private JTextField field;
private JLabel label;
private JButton button;
private ClientModel model;
public ClientMainFrame(){
super("聊天室客户端v1.0");
area=new JTextArea(20,40);
field=new JTextField(25);
button=new JButton("发送");
label=new JLabel();
JScrollPane jsp=new JScrollPane(area);
this.add(jsp,BorderLayout.CENTER);
JPanel panel=new JPanel();
panel.add(label);
panel.add(field);
panel.add(button);
this.add(panel,BorderLayout.SOUTH);
addEventHandler();
}
public ClientMainFrame(ClientModel model){
this();
this.model=model;
label.setText(model.getCurrentUser().getName());
}
public void addEventHandler(){
ActionListener lis=new SendEventListener();
button.addActionListener(lis);
field.addActionListener(lis);
this.addWindowListener(new WindowAdapter(){
public void windowClosing(WindowEvent arg0) {
int op=JOptionPane.showConfirmDialog(null,"确认退出聊天室吗？","确认退出",JOptionPane.YES_NO_OPTION);
if(op==JOptionPane.YES_OPTION){
PrintWriter pw = model.getOutputStream();
if(model.getCurrentUser().getName()!=null){
pw.println("%EXIT%:"+model.getCurrentUser().getName());
pw.flush();
}
try {
Thread.sleep(200);
} catch (Exception e) {
}
System.exit(0);
}
}
});
}
public void showMe(){
this.pack();
this.setVisible(true);
this.setLocation(300,300);
this.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);
new ReadMessageThread().start();
}
class SendEventListener implements ActionListener{
public void actionPerformed(ActionEvent e) {
String str=field.getText().trim();
if(str.equals("")){
JOptionPane.showMessageDialog(null, "不能发送空消息！");
return;
}
PrintWriter pw = model.getOutputStream();
pw.println(model.getCurrentUser().getName()+":"+str);
pw.flush();
field.setText("");
}
}
class ReadMessageThread extends Thread{
public void run(){
while(true){
try {
BufferedReader br = model.getInputStream();
String str=br.readLine();
area.append(str+"\n");
} catch (IOException e) {
}
}
}
}
}
3：登陆界面：
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.PrintWriter;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JPasswordField;
import javax.swing.JTextField;
public class LoginFrame extends JFrame {
private static final long serialVersionUID = 1L;
private JPanel jContentPane = null;
private JLabel lab1 = null;
private JLabel lab2 = null;
private JLabel lab3 = null;
private JTextField userNameField = null;
private JPasswordField passwordField = null;
private JButton loginButton = null;
private JButton registerButton = null;
private JButton cancelButton = null;
private ClientModel model = null;
/**
* This method initializes userNameField
*
* @return javax.swing.JTextField
*/
private JTextField getUserNameField() {
if (userNameField == null) {
userNameField = new JTextField();
userNameField.setSize(new Dimension(171, 33));
userNameField.setFont(new Font("Dialog", Font.PLAIN, 18));
userNameField.setLocation(new Point(140, 70));
}
return userNameField;
}
/**
* This method initializes passwordField
*
* @return javax.swing.JPasswordField
*/
private JPasswordField getPasswordField() {
if (passwordField == null) {
passwordField = new JPasswordField();
passwordField.setSize(new Dimension(173, 30));
passwordField.setFont(new Font("Dialog", Font.PLAIN, 18));
passwordField.setLocation(new Point(140, 110));
}
return passwordField;
}
/**
* This method initializes loginButton
*
* @return javax.swing.JButton
*/
private JButton getLoginButton() {
if (loginButton == null) {
loginButton = new JButton();
loginButton.setLocation(new Point(25, 180));
loginButton.setText("登录");
loginButton.setSize(new Dimension(75, 30));
}
return loginButton;
}
/**
* This method initializes cancelButton
*
* @return javax.swing.JButton
*/
private JButton getCancelButton() {
if (cancelButton == null) {
cancelButton = new JButton();
cancelButton.setLocation(new Point(270, 180));
cancelButton.setText("取消");
cancelButton.setSize(new Dimension(75, 30));
}
return cancelButton;
}
/**
* 显示界面的方法，在该方法中调用addEventHandler()方法给组件添加事件监听器
*
*/
public void showMe(){
this.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);
this.setVisible(true);
this.setLocation(300,200);
addEventHandler();
}
/**
* 该方法用于给组件添加事件监听
*
*/
public void addEventHandler(){
ActionListener loginListener=new LoginEventListener();
loginButton.addActionListener(loginListener);
passwordField.addActionListener(loginListener);
cancelButton.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e) {
try {
model.getSocket().close();
} catch (IOException e1) {
e1.printStackTrace();
}
System.exit(0);
}
});
this.addWindowListener(new WindowAdapter(){
public void windowClosing(WindowEvent arg0) {
try {
model.getSocket().close();
} catch (IOException e1) {
e1.printStackTrace();
}
System.exit(0);
}
});
}
/**
* 该内部类用来监听登录事件
* @author Administrator
*
*/
class LoginEventListener implements ActionListener{
public void actionPerformed(ActionEvent e) {
//?????登录的代码
//1,判断用户名和密码是否为空
//2，从clientmodel得到输出流，PrintWriter
//3，发送登录请求给服务器
//pw.println("%LOGIN%:userName:password");
//4,从socket得到对象输入流，从流中读取一个对象。
//5，如果读到的对象为null，则显示登录失败的消息。
//6，如果读到的对象不为空，则转成User对象，并且将
// clientModel的currentUser对象设置为该对象。
//7，并销毁当前窗口，打开主界面窗口。
String userName = userNameField.getText();
char[] c = passwordField.getPassword();
String password = String.valueOf(c);
if(userName == null || userName.equals("")){
JOptionPane.showMessageDialog(null,"用户名不能为空");
return;
}
if(password == null || password.equals("")){
JOptionPane.showMessageDialog(null,"密码名不能为空");
return;
}
PrintWriter pw = model.getOutputStream();
pw.println("%LOGIN%:"+userName+":"+password);
pw.flush();
try {
InputStream is = model.getSocket().getInputStream();
System.out.println("is"+is.getClass());
ObjectInputStream ois = new ObjectInputStream(is);
Object obj = ois.readObject();
if(obj != null){
User user = (User)obj;
if(user != null){
model.setCurrentUser(user);
LoginFrame.this.dispose();
new ClientMainFrame(model).showMe();
}
}
else{
JOptionPane.showMessageDialog(null,"用户名或密码错误，请重新输入");
userNameField.setText("");
passwordField.setText("");
return;
}
} catch (Exception e1) {
e1.printStackTrace();
}
}
}
public static void main(String[] args) {
new LoginFrame().showMe();
}
/**
* This is the default constructor
*/
public LoginFrame(ClientModel model) {
this();
this.model=model;
}
public LoginFrame(){
super();
initialize();
}
public ClientModel getModel() {
return model;
}
public void setModel(ClientModel model) {
this.model = model;
}
/**
* This method initializes this
*
* @return void
*/
private void initialize() {
this.setSize(362, 267);
this.setContentPane(getJContentPane());
this.setTitle("达内聊天室--用户登录");
}
/**
* This method initializes jContentPane
*
* @return javax.swing.JPanel
*/
private JPanel getJContentPane() {
if (jContentPane == null) {
lab3 = new JLabel();
lab3.setText("密 码：");
lab3.setSize(new Dimension(80, 30));
lab3.setFont(new Font("Dialog", Font.BOLD, 18));
lab3.setLocation(new Point(50, 110));
lab2 = new JLabel();
lab2.setText("用户名：");
lab2.setSize(new Dimension(80, 30));
lab2.setToolTipText("");
lab2.setFont(new Font("Dialog", Font.BOLD, 18));
lab2.setLocation(new Point(50, 70));
lab1 = new JLabel();
lab1.setBounds(new Rectangle(54, 12, 245, 43));
lab1.setFont(new Font("Dialog", Font.BOLD, 24));
lab1.setForeground(new Color(0, 0, 204));
lab1.setText("聊天室--用户登录");
jContentPane = new JPanel();
jContentPane.setLayout(null);
jContentPane.add(lab1, null);
jContentPane.add(lab2, null);
jContentPane.add(lab3, null);
jContentPane.add(getUserNameField(), null);
jContentPane.add(getPasswordField(), null);
jContentPane.add(getLoginButton(), null);
jContentPane.add(getCancelButton(), null);
}
return jContentPane;
}
}
4：客户端管理socket类
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;
/**
* 该类定义客户端的全局参数，如：Socket，当前用户,流对象等
*
*/
public class ClientModel {
private Socket socket;
private User currentUser;
private BufferedReader br;
private PrintWriter pw;
private String hostName;
private int port;
public Socket getSocket() {
return socket;
}
public ClientModel(String hostName, int port) {
super();
this.hostName = hostName;
this.port = port;
}
public User getCurrentUser() {
return currentUser;
}
public void setCurrentUser(User currentUser) {
this.currentUser = currentUser;
}
public synchronized Socket createSocket(){
if(socket==null){
try {
socket=new Socket(hostName,port);
}catch (IOException e) {
e.printStackTrace();
return null;
}
}
return socket;
}
public synchronized BufferedReader getInputStream(){
if (br==null) {
try {
br = new BufferedReader(new InputStreamReader(socket
.getInputStream()));
} catch (IOException e) {
e.printStackTrace();
return null;
}
}
return br;
}
public synchronized PrintWriter getOutputStream(){
if (pw==null) {
try {
pw = new PrintWriter(socket.getOutputStream());
} catch (IOException e) {
e.printStackTrace();
return null;
}
}
return pw;
}
public synchronized void closeSocket(){
if(socket!=null){
try {
br.close();
pw.close();
socket.close();
} catch (IOException e) {
e.printStackTrace();
}
}
socket=null;
br=null;
pw=null;
}
}
这里是工具和POJO类：
User类：
import java.io.Serializable;
public class User implements Serializable {
private static final long serialVersionUID = 1986L;
private int id;
private String name;
private String password;
private String email;
public User(){}
public User( String name, String password, String email) {
super();
this.name = name;
this.password = password;
this.email = email;
}
public User( String name, String password) {
super();
this.name = name;
this.password = password;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public String toString(){
return id+":"+name+":"+password+":"+email;
}
}
DAO，用于从本地读取配置文件
接口：
public interface UserDao {
public boolean addUser(User user);
public User getUser(String userName,String password);
}
实现类：
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
public class UserDaoForTextFile implements UserDao{
private File userFile;
public UserDaoForTextFile(){
}
public UserDaoForTextFile(File file){
this.userFile = file;
if(!file.exists()){
try {
file.createNewFile();
} catch (IOException e) {
e.printStackTrace();
}
}
}
public synchronized boolean addUser(User user) {
FileInputStream fis = null;
BufferedReader br = null;
int lastId = 0;
try{
fis = new FileInputStream(userFile);
br = new BufferedReader(new InputStreamReader(fis));
String str = null;
String lastLine = null;
while((str=br.readLine()) != null){
//得到最后一行值
lastLine = str;
if(str.split(":")[1].equals(user.getName())){
return false;
}
}
if(lastLine != null)
lastId = Integer.parseInt(lastLine.split(":")[0]);
}catch(Exception e){
e.printStackTrace();
}finally{
if(br!=null)try{br.close();}catch(IOException e){}
if(fis!=null)try{fis.close();}catch(IOException e){}
}
FileOutputStream fos = null;
PrintWriter pw = null;
try{
fos = new FileOutputStream(userFile,true);
pw = new PrintWriter(fos);
user.setId(lastId+1);
pw.println(user);
pw.flush();
return true;
}catch(Exception e){
e.printStackTrace();
}finally{
if(pw!=null)try{pw.close();}catch(Exception e){}
if(fos!=null)try{fos.close();}catch(IOException e){}
}
return false;
}
public synchronized User getUser(String userName, String password) {
FileInputStream fis = null;
BufferedReader br = null;
String str = null;
User user = null;
try{
fis = new FileInputStream(userFile);
br = new BufferedReader(new InputStreamReader(fis));
while((str = br.readLine()) != null){
String[] s = str.split(":");
if(userName.equals(s[1]) password.equals(s[2])){
user = new User();
user.setId(Integer.parseInt(s[0]));
user.setName(s[1]);
user.setPassword(s[2]);
user.setEmail(s[3]);
}
}
}catch(IOException e){
e.printStackTrace();
}finally{
if(br!=null)try{br.close();}catch(IOException e){}
if(fis!=null)try{fis.close();}catch(IOException e){}
}
return user;
}
}
配置文件格式为：
id流水号:用户名:密码:邮箱
1:yawin:034437:yawin@126.com
2:zhoujg:034437:zhou@126.com
在java Socket编程中（client给server发送一个字符串，再由server返回一个字符串给client）
SERVER端：
--------------------------------------------------------
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
public class Server extends Thread {
private Socket clientSocket;
public Server(Socket clientSocket) {
this.clientSocket = clientSocket;
}
public void run() {
DataInputStream dis = null;
DataOutputStream dos = null;
try {
dis = new DataInputStream(clientSocket.getInputStream());
dos = new DataOutputStream(clientSocket.getOutputStream());
while (true) {
String temp = dis.readUTF();
if ("over".equals(temp)) {
break;
}
dos.writeUTF("from server:" + temp);
}
} catch (Exception e) {
//e.printStackTrace();
} finally {
try {
if (dis != null) {
dis.close();
}
if (dis != null) {
dos.close();
}
if (clientSocket != null) {
clientSocket.close();
}
} catch (IOException e) {
e.printStackTrace();
} finally {
System.out.println("Server Thread is shutdown.");
}
}
}
public static void main(String[] args) throws Exception {
ServerSocket ss = new ServerSocket(8008);
while (true) {
Socket clientSocket = ss.accept();
// 针对每个客户端, 启一个Server线程专门处理此客户端的请求。
Server server = new Server(clientSocket);
server.start();
}
}
}
CLIENT端：
----------------------------------------
import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.InputStreamReader;
import java.net.Socket;
public class Client {
public static void main(String[] args) throws Exception {
// 输入流1, 从键盘进入Client。
InputStreamReader isr = new InputStreamReader(System.in);
BufferedReader br = new BufferedReader(isr);
Socket clientSocket = new Socket("127.0.0.1", 8008);
// 输入流2, 从服务器端进入Client的流对象。
DataInputStream dis = new DataInputStream(clientSocket.getInputStream());
// 输出流, 从Client出去, 到服务器端。
DataOutputStream dos = new DataOutputStream(clientSocket.getOutputStream());
while (true) {
// 从键盘输入读取
String msg = br.readLine();
// 将读取信息发送给服务器端
dos.writeUTF(msg);
//输入over退出
if ("over".equals(msg)) {
break;
}
//读取从服务器返回的信息
String temp = dis.readUTF();
System.out.println(temp);
}
br.close();
dis.close();
dos.close();
clientSocket.close();
}
}
--------------------------------------------------------
用Java Socket编程，实现简单的Echo功能
// 服务器
import java.io.*;
import java.net.*;
public class MyServer {
public static void main(String[] args) throws IOException{
ServerSocket server=new ServerSocket(5678);
while (true) {
Socket client=server.accept();
BufferedReader in=new BufferedReader(new InputStreamReader(client.getInputStream()));
PrintWriter out=new PrintWriter(client.getOutputStream());
while(true){
String str=in.readLine();
System.out.println(str);
out.println("has receive....");
out.flush();
if(str.equals("exit"))
break;
}
client.close();
}
}
}
// 客户端
import java.net.*;
import java.io.*;
public class Client{
static Socket server;
public static void main(String[] args)throws Exception{
server=new Socket(InetAddress.getLocalHost(),5678);
BufferedReader in=new BufferedReader(new InputStreamReader(server.getInputStream()));
PrintWriter out=new PrintWriter(server.getOutputStream());
BufferedReader wt=new BufferedReader(new InputStreamReader(System.in));
while(true){
String str=wt.readLine();
out.println(str);
out.flush();
if(str.equals("end")){
break;
}
System.out.println(in.readLine());
}
server.close();
}
}
java socket编程，客户端发送文件给服务器，服务器接收到文件后如何返回确认信息告诉客户端文件已接收
import?java.io.BufferedReader;??
import?java.io.File;??
import?java.io.FileNotFoundException;??
import?java.io.FileOutputStream;??
import?java.io.IOException;??
import?java.io.InputStream;??
import?java.io.InputStreamReader;??
import?java.net.ServerSocket;??
import?java.net.Socket;??
??
??
/**?
?*??
?*?文件名：ServerReceive.java?
?*?实现功能：作为服务器接收客户端发送的文件?
?*??
?*?具体实现过程：?
?*?1、建立SocketServer，等待客户端的连接?
?*?2、当有客户端连接的时候，按照双方的约定，这时要读取一行数据?
?*??????其中保存客户端要发送的文件名和文件大小信息?
?*?3、根据文件名在本地创建文件，并建立好流通信?
?*?4、循环接收数据包，将数据包写入文件?
?*?5、当接收数据的长度等于提前文件发过来的文件长度，即表示文件接收完毕，关闭文件?
?*?6、文件接收工作结束?
?*??
?*??
?*?【注：此代码仅为演示客户端与服务器传送文件使用，?
?*??????每一个数据包之前没有文件协议命令?
?*??????具体的协议传输和文件传出的使用阶段可根据自己程序自行放置】?
?*??
?*??
?*?作者：小菜鸟?
?*?创建时间：2014-08-19?
?*??
?*?*/??
??
??
??
??
public?class?ServerReceive?{??
??
????public?static?void?main(String[]?args)?{??
??????????
????????/**与服务器建立连接的通信句柄*/??
????????ServerSocket?ss?=?null;??
????????Socket?s?=?null;??
??????????
????????/**定义用于在接收后在本地创建的文件对象和文件输出流对象*/??
????????File?file?=?null;??
????????FileOutputStream?fos?=?null;??
??????????
????????/**定义输入流，使用socket的inputStream对数据包进行输入*/??
????????InputStream?is?=?null;??
??????????
????????/**定义byte数组来作为数据包的存储数据包*/??
????????byte[]?buffer?=?new?byte[4096?*?5];??
??????????
????????/**用来接收文件发送请求的字符串*/??
????????String?comm?=?null;??
??????????
??????????
????????/**建立socekt通信，等待服务器进行连接*/??
????????try?{??
????????????ss?=?new?ServerSocket(4004);??
????????????s?=?ss.accept();??
????????}?catch?(IOException?e)?{??
????????????e.printStackTrace();??
????????}??
??????????
??????????
????????/**读取一行客户端发送过来的约定信息*/??
????????try?{??
????????????InputStreamReader?isr?=?new?InputStreamReader(s.getInputStream());??
????????????BufferedReader?br?=?new?BufferedReader(isr);??
????????????comm?=?br.readLine();??
????????}?catch?(IOException?e)?{??
????????????System.out.println("服务器与客户端断开连接");??
????????}??
??????????
????????/**开始解析客户端发送过来的请求命令*/??
????????int?index?=?comm.indexOf("/#");??
??????????
????????/**判断协议是否为发送文件的协议*/??
????????String?xieyi?=?comm.substring(0,?index);??
????????if(!xieyi.equals("111")){??
????????????System.out.println("服务器收到的协议码不正确");??
????????????return;??
????????}??
??????????
????????/**解析出文件的名字和大小*/??
????????comm?=?comm.substring(index?+?2);??
????????index?=?comm.indexOf("/#");??
????????String?filename?=?comm.substring(0,?index).trim();??
????????String?filesize?=?comm.substring(index?+?2).trim();??
??????????
??????????
????????/**创建空文件，用来进行接收文件*/??
????????file?=?new?File(filename);??
????????if(!file.exists()){??
????????????try?{??
????????????????file.createNewFile();??
????????????}?catch?(IOException?e)?{??
????????????????System.out.println("服务器端创建文件失败");??
????????????}??
????????}else{??
????????????/**在此也可以询问是否覆盖*/??
????????????System.out.println("本路径已存在相同文件，进行覆盖");??
????????}??
??????????
????????/**【以上就是客户端代码中写到的服务器的准备部分】*/??
??????????
??????????
????????/**?
?????????*?服务器接收文件的关键代码*/??
????????try?{??
????????????/**将文件包装到文件输出流对象中*/??
????????????fos?=?new?FileOutputStream(file);??
????????????long?file_size?=?Long.parseLong(filesize);??
????????????is?=?s.getInputStream();??
????????????/**size为每次接收数据包的长度*/??
????????????int?size?=?0;??
????????????/**count用来记录已接收到文件的长度*/??
????????????long?count?=?0;??
??????????????
????????????/**使用while循环接收数据包*/??
????????????while(count??file_size){??
????????????????/**从输入流中读取一个数据包*/??
????????????????size?=?is.read(buffer);??
??????????????????
????????????????/**将刚刚读取的数据包写到本地文件中去*/??
????????????????fos.write(buffer,?0,?size);??
????????????????fos.flush();??
??????????????????
????????????????/**将已接收到文件的长度+size*/??
????????????????count?+=?size;??
????????????????System.out.println("服务器端接收到数据包，大小为"?+?size);??
????????????}??
??????????????
????????}?catch?(FileNotFoundException?e)?{??
????????????System.out.println("服务器写文件失败");??
????????}?catch?(IOException?e)?{??
????????????System.out.println("服务器：客户端断开连接");??
????????}finally{??
????????????/**?
?????????????*?将打开的文件关闭?
?????????????*?如有需要，也可以在此关闭socket连接?
?????????????*?*/??
????????????try?{??
????????????????if(fos?!=?null)??
????????????????????fos.close();??
????????????}?catch?(IOException?e)?{??
????????????????e.printStackTrace();??
????????????}//catch?(IOException?e)??
????????}//finally??
??
????}//public?static?void?main(String[]?args)??
}//public?class?ServerReceive
Linux(或C语言)和JAVA下的socket编程有什么异同点
不同：
1.首先2者提供的接口不同，这点很容易区分。
2.java跨平台，写好的程序不用做任何修改就可以放到linux或者windows或者苹果等诸多操作系统上运行，C当然可以，但linux本身提供了socket的
系统调用
，你如果使用的是linux系统调用，那么你的程序只能在linux下运行，这点不难理解。但如果是C的
库函数
，那还是可以跨平台的
3.利用linux系统调用的速度是要快于JAVA提供的SOCKET接口。
相同性我就不说了，你看完我下面的话，你就能理解他们直接的关系了。
从你提出的问题，我觉的你可能对编程不是很了解。
socket是用来实现
进程通信
（主要是网络通信）的目的，但这不是语言能够解决的问题，确切的说语言连什么是进程他都不知道。这么说来SOCKET不是JAVA带的功能，那么JAVA是如何来实现这一功能的呢？JAVA是通过调用系统提供的SOCKET来完成的。
在LINUX里面，JAVA中的SCOKET最终就是通过调用系统提供的系统调用来完成，而系统调用的SOCKET则是操作系统和硬件共同完成的。所以他们共同点是，如果你的
JAVA程序
是在LINUX中运行的，那他们通信的具体过程会完全一样，只不过JAVA会在系统调用前面加上一些它认为必需加的东西或者是它认为能够方便编程人员使用的东西。
JAVA Socket编程和C++Socket编程有什么不同
Socket 是winsock里的原始套接字开发接口API，c++/java 他们是开发语言，而 socket 是一种通讯标准简称。首先，2者提供的接口不同（主要是封装形式不同），java 本身不带socket通讯底层实现的，而是通过调用系统底层的winsock API 进行的二次封装，而c/c++ 的socket可以理解为 更接近 系统层面的winsock,所以c/c++ 的socket 可以提供 更多的底层扩展与控制。 其次，从语言上讲，用JAVA发开出来的socket程序 可以在任何支持JAVA虚拟机上运行，不用修改任何代码。而 C/c++ 要根据系统特性进行适当的修改。