JAVA进阶-网络编程

阅读原文时间：2021年07月31日阅读：1

>通过套接字连接server

Socket指代套接字

>读取随意站点的首页

---------

/**
* @author Lean @date:2014-10-9
*/
public class SocketSample {

public static void main(String\[\] args) {  
    BufferedWriter writer=null;  
    Socket socket=null;  
    try {  
        while (true) {  
            try {  
                Thread.sleep(1000);  
            } catch (InterruptedException e) {  
                e.printStackTrace();  
            }  
            socket=new Socket("localhost",8080);  
            OutputStream outputStream=socket.getOutputStream();  
            outputStream.write("GET / HTTP/1.0\\n\\n".getBytes());  
            BufferedReader reader=new BufferedReader(new InputStreamReader(socket.getInputStream()));  
            writer=new BufferedWriter(new OutputStreamWriter(new FileOutputStream("C:/Users/Administrator/Desktop/TheadSample.html")));  
            String appendStr=null;  
            while ((appendStr=reader.readLine()) != null) {

// System.out.println(appendStr);
writer.write(appendStr);
}
writer.close();
reader.close();
}
} catch (UnknownHostException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}finally{
if (socket!=null) {
try {
socket.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}

}

---------

>通过url下载随意网页

---------

/**
* @author Lean @date:2014-10-9
*/
public class URLSample {

public static void main(String\[\] args) {

    try {  
        URL url=new URL("HTTP","www.baidu.com",80,"");

// URL url=new URL("http://www.baidu.com");
HttpURLConnection connection=(HttpURLConnection) url.openConnection();
connection.connect();
InputStream is=connection.getInputStream();
byte[] buff=new byte[1024];
int length=0;
while ((length=is.read(buff))!=-1) {
System.out.println(new String(buff));
}
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}

}

---------

>检測站点传入的cookie信息

---------

/**
* @author Lean @date:2014-10-9
*/
public class HttpCookieSample {

/\*\*  
 \* @param args  
 \*/  
public static void main(String\[\] args) {  
    CookieManager manager=new CookieManager();  
    manager.setCookiePolicy(new CustomerPolicy());  
    CookieHandler.setDefault(manager);  
    try {  
        URL url=new URL("http://www.baidu.com");  
        URLConnection conn=url.openConnection();  
        Object content=conn.getContent();  
        List<HttpCookie> cookies=manager.getCookieStore().getCookies();  
        for (HttpCookie httpCookie : cookies) {  
            System.out.println(httpCookie.getName()+"  "+httpCookie.getValue()+"    "+httpCookie.getDomain());  
            printCookieLiveAge(httpCookie);  
            System.out.println("Cookie secured:"+httpCookie.getSecure());  
            System.out.println("...........");

        }  
    } catch (MalformedURLException e) {  
        e.printStackTrace();  
    } catch (IOException e) {  
        e.printStackTrace();  
    }

}

private static void printCookieLiveAge(HttpCookie httpCookie) {  
    long age=httpCookie.getMaxAge();  
    SimpleDateFormat df=new SimpleDateFormat("HH:mm:ss");  
    System.out.println(age!=-1?"Cookie will expire when close ":"Cookie age is:"+df.format(age));  
}

static class CustomerPolicy implements CookiePolicy{

    @Override  
    public boolean shouldAccept(URI uri, HttpCookie cookie) {  
        return true;  
    }

}

}

---------

>编写同一时候服务多个client的server程序

---------

/**
* @author Lean @date:2014-10-9
*/
public class ServerSocketSample {

private static ServerSocket server=null;

public static void main(String\[\] args) {

    try {  
        server=new ServerSocket(8080);  
        ExecutorService pool=Executors.newFixedThreadPool(3);  
        while (true) {  
            Socket socketObject= server.accept();  
            pool.submit(new CustomRunnable(socketObject));  
        }  
    } catch (IOException e) {  
        e.printStackTrace();  
    }  
}

static class CustomRunnable implements Runnable{

    byte\[\] buff=new byte\[512\];  
    private Socket socketObject;  
    public CustomRunnable(Socket socketObject) {  
        this.socketObject=socketObject;  
    }

    @Override  
    public void run() {  
        try {  
            System.out.println("Thread ID>>"+Thread.currentThread().getId());  
            InputStream stream=socketObject.getInputStream();  
            stream.read(buff);  
            OutputStream os=socketObject.getOutputStream();  
            os.write(buff);  
            socketObject.close();  
        } catch (IOException e) {  
            e.printStackTrace();  
        }  
    }  
}

}

---------

>编写实际的文件存储server程序

---------

StorgeServerSample

/**
* @author Lean @date:2014-10-10
*/
public class StorgeServerSample {

public static void main(String\[\] args) {  
    ServerSocket socket=null;  
    ExecutorService service=Executors.newFixedThreadPool(Runtime.getRuntime().availableProcessors());  
    try {  
        socket=new ServerSocket(8080);  
        try {  
            while (true) {  
                Socket socketObject=socket.accept();  
                service.submit(new RequestRunnable(socketObject));  
            }  
        } finally{  
            socket.close();  
        }  
    } catch (IOException e) {  
        e.printStackTrace();  
    }

}

static class RequestRunnable implements Runnable{

    private Socket requestSocket;

    public RequestRunnable(Socket socketObject) {  
        requestSocket=socketObject;  
    }

    @Override  
    public void run() {  
        try {  
            DataInputStream dataIs=new DataInputStream(requestSocket.getInputStream());  
            DataOutputStream dataOs=new DataOutputStream(requestSocket.getOutputStream());  
            int cmd=dataIs.readInt();  
            String message=cmd==0?

"Put ":"Get ";
String fileName=dataIs.readUTF();
message+=fileName+" REQUEST";
fileName="C:/Documents and Settings/Administrator/桌面/Server.txt";
if (cmd==0) {
uploadFile(dataIs,fileName);
}else {
downFile(dataOs,fileName);
}
} catch (IOException e) {
e.printStackTrace();
}

    }

    private void uploadFile(DataInputStream dataIs, String fileName) {  
        try {  
            BufferedWriter writer=new BufferedWriter(new FileWriter(fileName));  
            String tempStr;  
            while (!(tempStr=dataIs.readUTF()).equals("-1")) {  
                writer.write(tempStr);  
                writer.newLine();  
            }  
            writer.close();  
            dataIs.close();  
        } catch (IOException e) {  
            e.printStackTrace();  
        }  
    }

    private void downFile(DataOutputStream dataOs, String fileName) {  
        try {  
            BufferedReader reader=new BufferedReader(new FileReader(fileName));  
            String tempStr=null;  
            while ((tempStr=reader.readLine())!=null) {  
                dataOs.writeUTF(tempStr);  
            }  
            dataOs.writeUTF("-1");  
            dataOs.close();  
            reader.close();  
        } catch (FileNotFoundException e) {  
            e.printStackTrace();  
        } catch (IOException e) {  
            e.printStackTrace();  
        }  
    }

}

}

---------

StorgeClientSample

public class StorgeClientSample {

public static void main(String\[\] args) {

    int cmd=1;  
    try {  
        Socket requestScoket=new Socket();  
        requestScoket.connect(new InetSocketAddress("localhost",8080));  
        if (cmd==0) {  
            String fileName="C:/Documents and Settings/Administrator/桌面/Test.txt";  
            BufferedReader reader=new BufferedReader(new FileReader(fileName));  
            DataOutputStream dataOs=new DataOutputStream(requestScoket.getOutputStream());  
            dataOs.writeInt(cmd);  
            dataOs.writeUTF(fileName);  
            String tempStr;  
            while ((tempStr=reader.readLine())!=null) {  
                System.out.println(tempStr);  
                dataOs.writeUTF(tempStr);  
            }  
            dataOs.writeUTF("-1");  
            dataOs.close();  
            reader.close();  
        }else {  
            String fileName="C:/Documents and Settings/Administrator/桌面/Down.txt";  
            BufferedWriter writer=new BufferedWriter(new FileWriter(fileName));  
            DataOutputStream dataOs=new DataOutputStream(requestScoket.getOutputStream());  
            dataOs.writeInt(cmd);  
            dataOs.writeUTF(fileName);  
            DataInputStream dataIs=new DataInputStream(requestScoket.getInputStream());  
            String tempStr;  
            while (!(tempStr=dataIs.readUTF()).equalsIgnoreCase("-1")) {  
                System.out.println(tempStr);  
                writer.write(tempStr);  
                writer.newLine();  
            }  
            dataIs.close();  
            writer.close();  
        }  
    } catch (IOException e) {  
        e.printStackTrace();  
    }

}

}

---------

>创建多电波server和client

---------

StockTradesServer

/**
* @author Lean @date:2014-10-11
*/
public class StockTradesServer {

public static void main(String\[\] args) {  
    Thread stockSThread=new Thread(new StockTradeGenerator());  
    stockSThread.setDaemon(true);  
    stockSThread.start();  
    try {  
        Thread.sleep(30000);  
    } catch (InterruptedException e) {  
    }  
}

static class StockTradeGenerator implements Runnable{

    private DatagramSocket broadcastSocket;  
    private String\[\] stockSymbols ={"IBM","SNE","XRX","MHP","NOK"};

    public StockTradeGenerator() {  
        try {  
            broadcastSocket=new DatagramSocket(4445);  
        } catch (SocketException e) {  
            System.out.println("error create socket ! ");  
        }  
    }

    @Override  
    public void run() {  
        byte\[\] buff=new byte\[126\];  
        try {  
            while (true) {  
                int index=(int) (Math.random()\*5);  
                float trade=generatorRandomTrade(index);  
                String tempStr=String.format("%s %.2f@ %s",stockSymbols\[index\],trade,now());  
                buff=tempStr.getBytes();  
                InetAddress groupInetAddresses;  
                    groupInetAddresses = InetAddress.getLocalHost();  
                DatagramPacket datagramPacket=new DatagramPacket(buff,buff.length, groupInetAddresses,4446);  
                broadcastSocket.send(datagramPacket);  
                Thread.sleep(500);  
            }  
        } catch (UnknownHostException e) {  
            e.printStackTrace();  
        } catch (IOException e) {  
            e.printStackTrace();  
        } catch (InterruptedException e) {  
            e.printStackTrace();  
        }finally{  
            broadcastSocket.close();  
        }  
    }

}

public static float generatorRandomTrade(int index) {  
    float trade=(float) Math.random();  
    switch (index) {  
        case 0:  
            trade+=118;  
            break;  
        case 1:  
            trade+=29;  
            break;  
        case 2:  
            trade+=8;  
            break;  
        case 3:  
            trade+=26;  
            break;  
        case 4:  
            trade+=14;  
            break;  
        default:  
            break;  
    }  
    return trade;  
}

public static Object now() {  
    SimpleDateFormat df=new SimpleDateFormat("HH:mm:ss");  
    Date date=new Date();  
    return df.format(date);  
}

}

---------

StockTradeClient

/**
* @author Lean @date:2014-10-11
*/
public class StockTradeClient {

public static void main(String\[\] args) throws IOException {  
    MulticastSocket multicastSocket=new MulticastSocket(4446);  
    InetAddress address=InetAddress.getByName("232.0.1.1");  
    multicastSocket.joinGroup(address);  
    for (int i = 0; i < 10; i++) {  
        byte\[\] buff=new byte\[256\];  
        DatagramPacket datagramPacket=new DatagramPacket(buff,buff.length);  
        multicastSocket.receive(datagramPacket);  
        System.out.println(new String(datagramPacket.getData(),0,datagramPacket.getLength()));  
    }  
    multicastSocket.leaveGroup(address);  
    multicastSocket.close();  
}

}

---------

网络基础知识(转)

**Ip:提供了数据的发送地址和接收地址;位于网络层;

Tcp:三次握手,"带重定向的肯定确认"技术来实现传输可靠性,"滑动窗体"的流量控制

对Ip包进行解包,并对分解的tcp包进行排序,假设出错,即发出又一次请求的信号

Udp:面向无连接的传输数据协议,可当做广播处理,不监控包的顺序,速度快,easy产生丢包现象;

Icmp:为ip指出通向目标地址的路径信息.

通讯port:以源地址源port,目标地址目标port作为确定,并依靠传输层协议对每次传输进行确认

数据格式:帧头+IP数据包+帧尾（帧头包含源和目标主机MAC地址及类型，帧尾是校验字）

IP数据包：IP头部+TCP数据信息（IP头包含源和目标主机IP地址、类型、生存期等）

TCP数据信息：TCP头部+实际数据 (TCP头包含源和目标主机port号、顺序号、确认号、校验字等）