实验六: Java流式编程与网络程序设计

一、字节输入/输出流实现数据的保存和读取

package step1;


import java.io.*;
import java.util.*;

public class SortArray {

    public static void main(String[] args) {
        /********** Begin **********/
        // 创建保存整型数据的数组(数组大小10)
        int[] data = new int[10];

        // 给数组赋随
        Scanner sc = new Scanner(System.in);
        for (int i = 0; i < data.length; i++) {
            data[i] = sc.nextInt();
        }
        // 将数组元素按有小到大顺序排列
        Arrays.sort(data);

        try {
            // 创建数据保存文件，如果文件不存在，重新创建
            File file = new File("data.txt");
            if (!file.exists()) {
                file.createNewFile();
            }
            // 创建FileOutputStream和DataOutputStream 输出流
            FileOutputStream fileOutputStream = new FileOutputStream(file);
            DataOutputStream dataOutputStream = new DataOutputStream(fileOutputStream);

            // 利用输出流向文件中写入数组数据
            for (int datum : data) {
                dataOutputStream.writeInt(datum);
            }

            // 关闭输出流
            dataOutputStream.close();

            // 创建FileInputStream和DataInputStream 输入流
            FileInputStream fileInputStream = new FileInputStream(file);
            DataInputStream dataInputStream = new DataInputStream(fileInputStream);

            // 利用输入流从文件读取数据并输出
            for (int i = 0; i < data.length; i++) {
                System.out.print(dataInputStream.readInt());
                if (i != data.length - 1) {
                    System.out.print("<");
                }
            }
            System.out.println();
            // 关闭输入流
            dataInputStream.close();

        } catch (IOException e) {
            // 异常处理
            System.out.println("读写发生异常");
        }
        /********** End **********/
    }
}

二、字符输入/输出流实现发送电报

package step2;

import java.io.*;
import java.util.Scanner;

public class Encrypt {
  public static void main(String[] args) throws IOException {

    // 创建要发送的电报
    Scanner sc = new Scanner(System.in);
    String data = sc.next();

    // 将电报分割成字符数组
    /********** Begin **********/
    char[] a = data.toCharArray();
    /********** End **********/

    // 打开指定存放电报的文件，如果文件不存在，则创建
    File file = new File("data.txt");
    if (!file.exists()) {
      file.createNewFile();
    }

    // 循环遍历字符数组，将每个字符加密处理
    for (int i = 0; i < a.length; i++) {
      a[i] = (char)(a[i] ^ 'q');
    }

    // 利用字符输出流FileWriter将加密后的字符数组写入文件中
    /********** Begin **********/
    FileWriter fileWriter = new FileWriter(file);
    fileWriter.write(a, 0, a.length);
    fileWriter.flush();
    fileWriter.close();
    /********** End **********/

    // 利用字符输入流FileReader读取文件，将密文输出
    /********** Begin **********/
    FileReader fileReader = new FileReader(file);
    char[] buffer = new char[10];
    int x; //保存读取的数据量
    System.out.println("密文：");
    while ((x = fileReader.read(buffer)) != -1) {
      System.out.print(new String(buffer));
    }
    fileReader.close();
    /********** End **********/

    // 利用字符输入流FileReader读取文件，将密文转换为明文输出
    /********** Begin **********/
    FileReader in = new FileReader(file);
    System.out.println("\n明文：");
    while ((x = in.read(buffer)) != -1) {
      for (int i = 0; i < x; i++) {
        buffer[i] = (char)(buffer[i] ^ 'q');
      }
      System.out.print(new String(buffer));
    }
    in.close();
    /********** End **********/
  }
}

三、简单TCP通信

 

客户端程序

Client.java代码

package step3;

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.net.InetAddress;
import java.net.Socket;
import java.util.Scanner;

public class Client {

    public static void main(String[] args) throws Exception {
        Server server = new Server();
        server.start();
        Scanner sc = new Scanner(System.in);

        //创建客户端Socket(s)，指定服务器端IP地址和端口号
        /********** Begin **********/
        Socket s = new Socket("127.0.0.1", 8080);

        /**********  end  **********/
        DataOutputStream dos = new DataOutputStream(s.getOutputStream());
        DataInputStream dis = new DataInputStream(s.getInputStream());
        System.out.println(dis.readUTF());
        String name = sc.next();
        dos.writeUTF(name);
        System.out.println(dis.readUTF());
        s.close();
    }
}

服务器端程序

Server.java代码

package step3;

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 {

    @Override
    public void run() {
        try {
            //创建服务器端ServerSocket(ss)，指定端口号8000
            /********** Begin **********/
            ServerSocket ss = new ServerSocket(8080);
            /**********  end  **********/
            Socket s = ss.accept();
            DataOutputStream dos = new DataOutputStream(s.getOutputStream());
            DataInputStream dis = new DataInputStream(s.getInputStream());
            dos.writeUTF("你已经连上服务器了，告诉我你的姓名...");
            String name = dis.readUTF();
            dos.writeUTF("再见:" + name);
            s.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

四、TCP通信实现奇偶数判断

ClientPlus.java

package step4;

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.EOFException;
import java.io.IOException;
import java.net.InetAddress;
import java.net.Socket;
import java.util.Scanner;

public class ClientPlus {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        ServerPlus server = new ServerPlus();
        server.start();
        try {
            //创建客户端Socket(s)，指定服务器端IP地址和端口号
            /********** Begin **********/
            Socket s = new Socket("127.0.0.1", 8080);
            /**********  end  **********/
            DataOutputStream dos = new DataOutputStream(s.getOutputStream());
            DataInputStream dis = new DataInputStream(s.getInputStream());
            //客户端通过循环依次接收服务器返回的结果，并输入新的整数传递给服务器
            /********** Begin **********/
            while (true) {
                System.out.println(dis.readUTF());
                String num = sc.next();
                dos.writeUTF(num);
            }
            /**********  end  **********/
        } catch (EOFException e) {
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

ServerPlus.java

package step4;

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;

public class ServerPlus extends Thread {
    @Override
    public void run() {
        try {
            /********** Begin **********/
            //创建服务器端ServerSocket(ss)，指定端口号8000
            ServerSocket ss = new ServerSocket(8080);
            /**********  end  **********/
            Socket s = ss.accept();
            DataOutputStream dos = new DataOutputStream(s.getOutputStream());
            DataInputStream dis = new DataInputStream(s.getInputStream());
            ReceiveThread thread = new ReceiveThread(s, dos, dis);
            thread.start();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

ReceiveThread.java

package step4;
 
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.Socket;
import java.net.SocketException;

class ReceiveThread extends Thread {
    DataOutputStream dos;
    DataInputStream dis;
    Socket s;
    public ReceiveThread(Socket s, DataOutputStream dos, DataInputStream dis) {
        this.s = s;
        this.dos = dos;
        this.dis = dis;
    }
    @Override
    public void run() {
        try {
            dos.writeUTF("请输入一个整数，我知道是奇数还是偶数");
            while(true) {
                String num = dis.readUTF();
                if("-1".equals(num)) {
                    s.close();
                    break;
                } 
                String result = (Integer.parseInt(num)%2==0)?"偶数":"奇数";
                dos.writeUTF(num + "是..." + result);
            }            
        } catch (SocketException e) {
            try {
                s.close();
            } catch (IOException e1) {
                e1.printStackTrace();
            }
        } catch (IOException e) {
            System.out.println("数据读取异常");
        } 
    }    
}