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 PROGRAMOWANIE W ŚRODOWISKU SIECIOWYM I

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Serializacja obiektów

Code Sample 1: SaveDate.java

import java.io.*;

import java.util.Date;

public class SaveDate {

public static void main(String argv[]) throws Exception {

FileOutputStream fos = new FileOutputStream("date.out");

ObjectOutputStream oos = new ObjectOutputStream(fos);

Date date = new Date();

oos.writeObject(date);

oos.flush();

oos.close();

fos.close();

}

}

Code Sample 2: ReadDate.java

import java.io.*;

import java.util.Date;

public class ReadDate {

public static void main(String argv[]) throws Exception {

FileInputStream fis = new FileInputStream("date.out");

ObjectInputStream ois = new ObjectInputStream(fis);

Date date = (Date) ois.readObject();

System.out.println("The date is: "+date);

ois.close();

fis.close();

}

}

Code Sample 3: UserInfo.java

import java.io.*;

import java.util.*;

public class UserInfo implements Serializable {

String name = null;

public UserInfo(String name) {

this.name = name;

}

public void printInfo() {

System.out.println("The name is: "+name);

}

}

Code Sample 4: SaveInfo.java

import java.io.*;

import java.util.Date;

public class SaveInfo {

public static void main(String argv[]) throws Exception {

FileOutputStream fos = new FileOutputStream("name.out");

ObjectOutputStream oos = new ObjectOutputStream(fos);

// create two objects

UserInfo user1 = new UserInfo("Java Duke");

UserInfo user2 = new UserInfo("Java Blue");

// write the objects to the output stream

oos.writeObject(user1);

oos.writeObject(user2);

oos.flush();

oos.close();

fos.close();

}

}

Code Sample 5: ReadInfo.java

import java.io.*;

import java.util.Date;

public class ReadInfo {

public static void main(String argv[]) throws Exception {

FileInputStream fis = new FileInputStream("name.out");

ObjectInputStream ois = new ObjectInputStream(fis);

// read the objects from the input stream (the file name.out)

UserInfo user1 = (UserInfo) ois.readObject();

UserInfo user2 = (UserInfo) ois.readObject();

// invoke a method on the constructed object

user1.printInfo();

user2.printInfo();

ois.close();

fis.close();

}

}

Code Sample 6: DateServer.java

import java.io.*;

import java.net.*;

import java.util.*;

public class DateServer extends Thread {

private ServerSocket dateServer;

public static void main(String argv[]) throws Exception {

new DateServer();

}

public DateServer() throws Exception {

dateServer = new ServerSocket(3000);

System.out.println("Server listening on port 3000.");

this.start();

}

public void run() {

while(true) {

try {

System.out.println("Waiting for connections.");

Socket client = dateServer.accept();

System.out.println("Accepted a connection from: "+

client.getInetAddress());

Connect c = new Connect(client);

} catch(Exception e) {}

}

}

}

class Connect extends Thread {

private Socket client = null;

private ObjectInputStream ois = null;

private ObjectOutputStream oos = null;

public Connect() {}

public Connect(Socket clientSocket) {

client = clientSocket;

try {

ois = new ObjectInputStream(client.getInputStream());

oos = new ObjectOutputStream(client.getOutputStream());

} catch(Exception e1) {

try {

client.close();

}catch(Exception e) {

System.out.println(e.getMessage());

}

return;

}

this.start();

}

public void run() {

try {

oos.writeObject(new Date());

oos.flush();

// close streams and connections

ois.close();

oos.close();

client.close();

} catch(Exception e) {}

}

}

Code Sample 7: DateClient.java

import java.io.*;

import java.net.*;

import java.util.*;

public class DateClient {

public static void main(String argv[]) {

ObjectOutputStream oos = null;

ObjectInputStream ois = null;

Socket socket = null;

Date date = null;

try {

// open a socket connection

socket = new Socket("IP", 3000);

// open I/O streams for objects

oos = new ObjectOutputStream(socket.getOutputStream());

ois = new ObjectInputStream(socket.getInputStream());

// read an object from the server

date = (Date) ois.readObject();

System.out.print("The date is: " + date);

oos.close();

ois.close();

} catch(Exception e) {

System.out.println(e.getMessage());

}

}

}

Code Sample 8: SerializedObject.java

import java.io.*;

import java.util.*;

public class SerializedObject implements Serializable {

private int array[] = null;

public SerializedObject() {

}

public void setArray(int array[]) {

this.array = array;

}

public int[] getArray() {

return array;

}

}

Code Sample 9: ArrayClient.java

import java.io.*;

import java.net.*;

public class ArrayClient {

public static void main(String argv[]) {

ObjectOutputStream oos = null;

ObjectInputStream ois = null;

// two arrays

int dataset1[] = {3, 3, 3, 3, 3, 3, 3};

int dataset2[] = {5, 5, 5, 5, 5, 5, 5};

try {

// open a socket connection

Socket socket = new Socket("YourMachineNameORipAddress", 4000);

// open I/O streams for objects

oos = new ObjectOutputStream(socket.getOutputStream());

ois = new ObjectInputStream(socket.getInputStream());

// create two serialized objects

SerializedObject so1 = new SerializedObject();

SerializedObject so2 = new SerializedObject();

SerializedObject result = null;

int outArray[] = new int[7];

so1.setArray(dataset1);

so2.setArray(dataset2);

// write the objects to the server

oos.writeObject(so1);

oos.writeObject(so2);

oos.flush();

// read an object from the server

result = (SerializedObject) ois.readObject();

outArray = result.getArray();

System.out.print("The new array is: ");

// after unpacking the array, iterate through it

for(int i=0;i<outArray.length;i++) {

System.out.print(outArray[i] + " ");

}

oos.close();

ois.close();

} catch(Exception e) {

System.out.println(e.getMessage());

}

}

}

Code Sample 10: ArrayMultiplier

import java.io.*;

import java.net.*;

public class ArrayMultiplier extends Thread {

private ServerSocket arrayServer;

public static void main(String argv[]) throws Exception {

new ArrayMultiplier();

}

public ArrayMultiplier() throws Exception {

arrayServer = new ServerSocket(4000);

System.out.println("Server listening on port 4000.");

this.start();

}

public void run() {

while(true) {

try {

System.out.println("Waiting for connections.");

Socket client = arrayServer.accept();

System.out.println("Accepted a connection from: "+

client.getInetAddress());

Connect c = new Connect(client);

} catch(Exception e) {}

}

}

}

class Connect extends Thread {

private Socket client = null;

private ObjectInputStream ois = null;

private ObjectOutputStream oos = null;

public Connect() {}

public Connect(Socket clientSocket) {

client = clientSocket;

try {

ois = new ObjectInputStream(client.getInputStream());

oos = new ObjectOutputStream(client.getOutputStream());

} catch(Exception e1) {

try {

client.close();

}catch(Exception e) {

System.out.println(e.getMessage());

}

return;

}

this.start();

}

public void run() {

SerializedObject x = null;

SerializedObject y = null;

int dataset1[] = new int[7];

int dataset2[] = new int[7];

int result[] = new int[7];

try {

x = (SerializedObject) ois.readObject();

y = (SerializedObject) ois.readObject();

dataset1 = x.getArray();

dataset2 = y.getArray();

// create an array by multiplying two arrays

for(int i=0;i<dataset1.length;i++) {

result[i] = dataset1[i] * dataset2[i];

}

// ship the object to the client

SerializedObject output = new SerializedObject();

output.setArray(result);

oos.writeObject(output);

oos.flush();

// close connections

ois.close();

oos.close();

client.close();

} catch(Exception e) {}

}

}

Materiał:

http://java.sun.com/developer/technicalArticles/ALT/sockets/

ZADANIE

1) Posługując się programem klient-serwer z pierwszego ćwiczenia, zaimplementować przesyłanie poleceń poprzez obiekt klasy Command, która powinna zostać serializowana tak jak jest podane w przykladzie 6 i 7. Klasa Command powinna implementować interfejs Serializabe (przykład 8).

Przykladowe pola klasy Command to: ID, NAME, CMD, DATA (nie implemntować pola klasy File).

2) Zaimplementować nowe polecenie file, zawierające nazwę pliku,który ma zostac przesłany z serwera do klienta. Plik powinien być przesyłany w polu DATA (typ String).

3) Zaimplemntować dodatkowo polecneie DIR, przesyłające nazwykatalogów i pików z katalogu roboczego.