Java Socket File 전송

Java Socket File 전송 예제

 

1. Server

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;

/*
 * file transfer example
 * just in case various file name length
 * */
public class FileTransferServer {
	
	ServerSocket server;
	Socket socket;
	final int PORT = 8091;
	
	DataInputStream dis;
	FileOutputStream fos;
	File file;
	
	String filePath;
	byte[] buffer;
	int length;
	
	public FileTransferServer() {
		filePath = ".//Server//";
		buffer = new byte[1024];
	}
	
	public void start() {
		//server start
		try {
			server = new ServerSocket(PORT);
			socket = server.accept();				// wait for connected client
			dis = new DataInputStream(socket.getInputStream());
			
			int fileCnt = dis.readInt();
			for(int i=0; i<fileCnt; i++) {
				String fileName = dis.readUTF();
				file = new File(filePath+fileName);
				file.createNewFile();					// create a file
				System.out.println(file.getName());
				
				// start to write content to the file
				long fileSize = dis.readLong();
				long data = 0;
				fos = new FileOutputStream(file);
				while((length = dis.read(buffer))!= -1) {
					fos.write(buffer,0,length);
					data += length;
					if(data == fileSize)	break;		// end of the file
				}
			}
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} finally {
			try {
				fos.close();
				dis.close();
				server.close();
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
	}
	
 	public static void main(String[] args) {
 		new FileTransferServer().start();
	}
}

 

2.Client

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.net.Socket;
import java.net.UnknownHostException;

public class FileTransferClient {
	
	Socket socket;
	final String IP = "127.0.0.1";
	final int PORT = 8091;
	
	DataOutputStream dos;
	FileInputStream fis;
	File dir;
	
	String filePath = ".//Client";
	int length;
	byte[] buffer;
	
	public FileTransferClient() {
		buffer = new byte[1024];
	}
	
	public void start() {
		try {
			socket = new Socket(IP,PORT);
			dos = new DataOutputStream(socket.getOutputStream());
			// file read
			dir = new File(filePath);
			dos.writeInt(dir.listFiles().length);	// send file cnt
			for(File file : dir.listFiles()) {
				if(file.isFile()) {					// only in case of file
					dos.writeUTF(file.getName());
					fis = new FileInputStream(file);
					dos.writeLong(file.length());	// send file size
					while((length = fis.read(buffer))!=-1) {
						dos.write(buffer,0,length);
						dos.flush();
					}
				}
			}
		} catch (UnknownHostException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		
		System.exit(0);
	}
	
	public static void main(String[] args) {
		new FileTransferClient().start();
		System.out.println("system exit");
	}
}