client.java

这是我写的一个关于JAVA SOCKET的程序

import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.Socket;
import java.net.UnknownHostException;
import java.util.Properties;


public class Client {

	/**
	 * @param args
	 */
	private String ip = null;
	private int portNum;
	// client socket
	private Socket s = null;
	// client io communication with server
	private DataInputStream dis = null;
	private DataOutputStream dos = null;
	// console input io stream
	private BufferedReader sin = null;
	private String input = null;
	// data from server
	private String clientReadData = null;
	// shared secret key
	private String sharedKey = null;
	// for getting stuff from file, like pw hash value, secret key
	private Properties pro = null;
	// user name
	private String userName = null;
	// bye
	private static final String BYE_BYE = "bye";

	/*
	 * constructor
	 */
	public Client(String ip, int portNum) {
		this.ip = ip;
		this.portNum = portNum;
		this.sin = new BufferedReader(new InputStreamReader(System.in));
		pro = new Properties();
		desApp = new DesApp();
	}

	/*
	 * initialize client socket with the assigned ip and associated port number,
	 * also the io stream between the server and itself
	 */
	private void intialize() {
		try {
			s = new Socket(ip, portNum);
			dos = new DataOutputStream(s.getOutputStream());
			dis = new DataInputStream(s.getInputStream());
		} catch (UnknownHostException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

	/*
	 * client write info to client
	 */
	private void clientWrite(String info) {

		try {
			dos.writeUTF(info);
			dos.flush();
		} catch (IOException e) {
			e.printStackTrace();
		}

	}

	/*
	 * console promote input
	 */
	private String consoleInput() {

		try {
			input = sin.readLine();
		} catch (IOException e) {
			e.printStackTrace();
		}

		return input;
	}

	/*
	 * read data from server
	 */
	private String clientRead() {
		try {
			clientReadData = dis.readUTF();
		} catch (IOException e) {
			e.printStackTrace();
		}
		return clientReadData;
	}

	/*
	 * get the user's shared key
	 */
	private String getSharedKey(String fileName, String userName) {

		try {
			pro.load(this.getClass().getResourceAsStream(fileName));
		} catch (IOException e) {
			e.printStackTrace();
		}
		sharedKey = pro.getProperty(userName);
		return sharedKey;
		// return pwHashInServer;
	}

	/*
	 * exit and close socket and all the io stream
	 */
	private void exit() {
		try {
			s.close();
			dis.close();
			dos.close();
		} catch (IOException e) {
			e.printStackTrace();
		}
		System.exit(0);
	}

	// control while loop
	private boolean go = true;

	/*
	 * ifGo
	 */
	private void setGo(boolean ifGo) {
		this.go = ifGo;
	}

	// encrypt msg from client
	private String beEncMsgC = null;
	// dencrypted msg by client
	private String beDencMsgC = null;
	// desApp
	DesApp desApp = null;
	//pw
	private String passWord = null;
	public void goClient() {
		this.intialize();
		/*
		 * promote username and pw input
		 */
		System.out.print("User name:");
		userName = this.consoleInput();
		this.clientWrite(userName);
		InputMasking masking = new InputMasking();
		String password = null;
		try {
			passWord = masking.getPassword("password: ");
		} catch (IOException ex) {
			ex.printStackTrace();
		}
		/*
		 * compute pw hash value
		 */
		this.clientWrite(String.valueOf(passWord.hashCode()));
		beEncMsgC = this.clientRead();
		// get the shared secret key
		desApp.getKey(this.getSharedKey(userName + ".key", userName));
		beDencMsgC = desApp.getDesString(beEncMsgC);

		/*
		 * if access denied client exit
		 */
		if (this.beDencMsgC.equals("Access denied")) {
			System.out.println(userName + " access has been denied");
			this.exit();
		} else if (this.beDencMsgC.equals("welcome " + userName + "!")) {
			System.out.println(this.beDencMsgC);
			// authentication successful, then start communicating with server
			while (go) {
				System.out.print(userName + " says:");
				this.beEncMsgC = desApp.getEncString(this.consoleInput());
				this.clientWrite(beEncMsgC);
				// if client say "bye", client exit
				if (desApp.getDesString(beEncMsgC).equals(BYE_BYE)) {
					this.setGo(false);
					System.out.println(userName + " disconnects with server");
					break;
				}
				this.beDencMsgC = desApp.getDesString(this.clientRead());
				System.out.println("Feedback from Server: " + this.beDencMsgC);
			}
			// jump out while loop, client disconnect with server finally
			this.exit();
		}

	}
}