client.java

HTTP协议 开发测试

import java.net.*;
import java.io.*;


public class Client {

 
 private static final int  socketPort = 80;
 

 public Client() {}

 /**
  * This method is used to send the client's request to the server.
  *
  * @param <code>Socket</code>object and <code>String</code> message object.
  * @return void.
  * @exception <code>IOException</code>.
  */
 public void sendMessage(Socket clientSocket, String message) {

  String clientRequest;
  System.out.println(message + " is listening to your request:\n");

  BufferedReader inFromClient = new BufferedReader(new InputStreamReader(System.in));
  
  
  try {

   DataOutputStream outToServer = new DataOutputStream(clientSocket.getOutputStream());
   clientRequest = inFromClient.readLine();
   outToServer.writeBytes(clientRequest + "\r\n\r\n");

  } catch (IOException ioe) {

   System.err.println("IO erro: ");
   ioe.printStackTrace();
  }
  
 }

 /**
  * The method header is used to get the header out from the server reply, and print it out to the console.
  *
  * @param <code>InputStream</code>
  * @return void
  * @exception <code>IOException</code>
  *
     */
 public void header(InputStream inFromServer) {

  String header = "";
  int temp;
  boolean isHeader = false;
  
  try {
   temp = inFromServer.read();
   System.out.println(temp);
   header += (char) temp;
   
  
   while (temp != -1 && !isHeader) {
    switch (temp) {
    case 13:
     temp = inFromServer.read();
     switch (temp) {
     case 10:
      header += (char) temp;
      if ((char) (temp = inFromServer.read()) == ('\r'))
       if ((char) (temp = inFromServer.read()) == ('\n'))
        isHeader = true;
      break;
     default:
      break;
     }
     break;
    default:
     break;
    }
    if (isHeader)
     break;
    temp = inFromServer.read();
    header += (char) temp;
   }

  } catch (IOException ioe) {

   System.err.println("IO erro: ");
   ioe.printStackTrace();
  }

   System.out.println("header:\n" + header + "\n");
 }

 /**
  * This method is used to change the flow that come from server to the type of "byte".
  *
  * @param <code>InputStream</code> object  and <code>Socket</code> object.
  * @return <code>byte[]</code>
  * @exception <code>EOFException</code> and <code>IOException</code>
  */
 public byte[] serverReply(InputStream inFromServer, Socket clientSocket) {

  int fileLength=0;
  byte[] buffer = null;
  
 
  try {
   
   fileLength = inFromServer.available();
  } catch (IOException e) {
   
   System.err.println("IO erro when \"inFromServer.available()\" ");
   e.printStackTrace();
  }
  
  buffer = new byte[fileLength];
  DataInputStream receivedFile = null;

  receivedFile = new DataInputStream(inFromServer);
   
  
  try {
   
    for (int i=0;i<buffer.length;i++){
     buffer[i] = receivedFile.readByte();
    }
  } catch (EOFException eof) {
   
   eof.printStackTrace();
  }catch (IOException e2) {
   
   e2.printStackTrace();
  }
 
  return buffer;
 }

 /**
  * This method is used to save the infomation from server to the local file.
  *
  * @param <code>BufferedReader</code> object and <code>byte[]</code> object.
  * @return void.
  * @exception <code>FileNotFoundException</code> and <code>IOException</code>.
  */
 public void saveFile(BufferedReader inFromClient, byte[] buffer) {

  System.out.println("Input a file name to save the header:\n");
  
 
  try {

   FileOutputStream fileout = new FileOutputStream(inFromClient.readLine());
   PrintStream ps = new PrintStream(fileout);
   ps.write(buffer);
   ps.close();

  } catch (FileNotFoundException fnfe) {

   System.err.println("The specified file is not exist!");
   fnfe.printStackTrace();

  } catch (IOException ioe) {

   System.err.println("IO erro: ");
   ioe.printStackTrace();
  }
 }


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

  
  Client client = new Client();
  Socket clientSocket = null;

 
  try {

   clientSocket = new Socket(args[0], socketPort);
  } catch (UnknownHostException unke) {

   System.err.println("The host is unknown!");
   unke.printStackTrace();
 
  } catch (IOException ioe) {

   System.err.println("IO erro: ");
   ioe.printStackTrace();
  } catch (SecurityException se) {

   System.err.println("A security manager exists and we cannot get throw it.");
   se.printStackTrace();
  }

  BufferedReader inFromClient = new BufferedReader(new InputStreamReader(
    System.in, "UTF-8"));

  InputStream inFromServer  = new BufferedInputStream(clientSocket.getInputStream());
  
  
  client.sendMessage(clientSocket, args[0]);      
  client.header(inFromServer);        
  byte[] buffer = client.serverReply(inFromServer, clientSocket); 
  client.saveFile(inFromClient, buffer);       
  clientSocket.close();          

 }

}