Java implements a client's operation to send a file to the server

Server Source code:

Import Java.io.bufferedreader;import Java.io.file;import Java.io.filenotfoundexception;import Java.io.fileoutputstream;import Java.io.ioexception;import Java.io.inputstream;import Java.io.InputStreamReader; Import Java.net.serversocket;import java.net.socket;/** * * File name: Serverreceive.java * Implementation function: As the server receives the files sent by the client * * Specific implementation process: * 1, the establishment of Socketserver, waiting for the client's connection * 2, when there is a client connection, in accordance with the Agreement between the parties, at this time to read a row of data * where the client to send the file name and size information * 3, according to the file name in the local creation of files, and establish a good flow of letters * 4, Loop receive packet, write the packet to file * 5, when the length of the received data is equal to the length of the file sent in advance file, that is, the file received, close the file * 6, the end of the File receive work * * * NOTE: This code only for the demo client and server transfer file use, * each packet before the file protocol life * Specific protocol transmission and the use of files out of the stage can be placed on their own program to place the "* * * * * * * * * * * * * * * * Created: 2014-08-19 * * */public class Serverreceive {public static void Mai N (string[] args) {/** A communication handle to the server to establish a connection */serversocket SS = null; Socket s = null;/** defines the file object and file output stream object that is used to create the locally created after the receive */file file = null; FileOutputStream fos = null;/** defines the input stream, uses the socket's inputstream to input the packet */inputstream is = null;/** defines a byte array to be the packet's storage packet */ byte[] buffer = new byte[4096 * 5];/** used to receive file send request string */string Comm = null;/** Build SOcekt communication, waiting for the server to connect */try {ss = new ServerSocket (4004); s = ss.accept ();} catch (IOException e) {e.printstacktrace ();} /** reads the contract information sent over a line of clients */try {InputStreamReader ISR = new InputStreamReader (S.getinputstream ()); BufferedReader br = new BufferedReader (ISR); comm = Br.readline ();} catch (IOException e) {System.out.println ("Server Disconnected from client");} /** begins parsing the request command sent by the client */int index = comm.indexof ("/#"),/** determines whether the protocol is the Protocol to send the file */string xieyi = comm.substring (0, index); Xieyi.equals ("111")) {System.out.println ("the server received an incorrect protocol code"); return;} /** parse out the file name and size */comm = comm.substring (index + 2); index = Comm.indexof ("/#"); String filename = comm.substring (0, index). Trim (); String filesize = comm.substring (index + 2). Trim ();/** create an empty file to receive the file */file = new file (filename); if (!file.exists ()) {try {File.createnewfile ();} catch (IOException e) {System.out.println ("server-side Create file failed");}} else{/** can also ask whether to overwrite */system.out.println ("This path already exists the same file, overwrite");} /** "Above is the preparation portion of the server that is written in the client code" *//** * server receives the key code of the file */try {/** wraps the file into the file output stream object */fos = new FileOutputStream (file); Long file_size = Long.parselong (filesize), is = S.getinputstream (),/**size is the length of each receive packet */int size = 0;/** Count is used to record the length of the received file */long count = 0;/** uses the while loop to receive the packet */while (Count < file_size) {/** reads a packet from the input stream */size = Is.read ( buffer);/** writes the packet just read to the local file */fos.write (buffer, 0, size), Fos.flush ();/** will have received the length of the file +size*/count + = size; SYSTEM.OUT.PRINTLN ("Server-side received packet, size" + size);}} catch (FileNotFoundException e) {System.out.println ("Server write file Failed"),} catch (IOException e) {System.out.println (" Server: Client disconnects "); finally{/** * Close Open File * If required, you can also close the socket connection * */try {if (fos! = null) Fos.close (),} catch (IOException e) {E.printstacktra CE ();} catch (IOException e)}//finally}//public static void Main (string[] args)}//public class serverreceive

Client source code:

Import Java.io.file;import java.io.fileinputstream;import Java.io.filenotfoundexception;import java.io.IOException ; Import Java.io.outputstream;import java.io.printstream;import java.net.socket;/** * * File name: Clientsend.java * Implementation function: Send a file as a client to the server * * Specific implementation process: * 1, establish a connection with the server side, ip:127.0.0.1, port:4004 * 2, the name and size of the file through a custom file transfer protocol, send to the server * 3, loop read local files, the text  Package sent to the data output stream * 4, close the file, end the transfer * * "NOTE: This code only for the demo client and server transfer files use, * each packet before the file Protocol command * Specific protocol transfer and file out of the use phase can be placed on their own program" * * * Small rookie * Creation Time: 2014-08-19 * * */public class Clientsend {public static void main (string[] args) {/** communication handle to the server connection */socket s = null /** defines a file object, which is the file to be sent * if you use an absolute path, do not forget to use the difference between '/' and ' \ ' * Specific differences, please query the reader by themselves * */file sendfile = new File ("API. CHM ");/** definition file input stream to open, read the file to be sent */fileinputstream FIS = null;/** defines a byte array to be the packet's storage packet */byte[] buffer = new byte[4096 * 5 ];/** defines the output stream, outputs the packet using the outputstream of the socket */outputstream OS = null;/** checks to see if the file to be sent exists */if (!sendfile.exists ()) { SYSTEM.OUT.PRINTLN ("Client: The file to be sent does not exist"); return;} /** connection to the server */try {s = new Socket ("127.0.0.1",4004);} catch (IOException e) {System.out.println ("Not connected to Server");} /** initializes the FIS object with a file object * to make it possible to extract the size of the file * */try {fis = new FileInputStream (sendfile);} catch (FileNotFoundException E1) {E1.print StackTrace ();} /** first sends information about the file to the server, so that the server can receive the relevant preparations * specific preparations, please review the server code. * * Sent content includes: Send file protocol code (here is 111)/#文件名 (with suffix name)/#文件大小 * */try {printstream PS = new PrintStream (S.getoutputstream ());p s.println ( "111/#" + sendfile.getname () + "/#" + fis.available ());p S.flush (); catch (IOException e) {System.out.println ("Server connection Interrupted");} /** * Here sleep 2s, waiting for the server to prepare the relevant work * also to ensure the delay of the network * readers can choose to add this code * */try {thread.sleep;} catch (Interruptedexception E1) {E1 . Printstacktrace ();} /** before the end of the preparation work * The following is the key code for file transfer * */try {/** Gets the outputstream of the socket in order to write packets to it */os = S.getoutputstream ();/** size Used to record the size of each read file */int size = 0;/** uses while loop to read the file until the end of the file read */while ((size = fis.read (buffer))! =-1) {System.out.println (" The client sends the packet with a size of "+";/** writes the packet just read to the output stream */os.write (buffer, 0, size);/** refresh */os.flush ();}} catch (FileNotFoundException e) {SYSTEM.OUT.PRINTLN ("Client read file Error");} catch (IOException e) {System.out.println ("error in client output file");} finally{/** * Close Open File * If required, you can also close the socket connection * */try {if (FIS! = null) Fis.close (),} catch (IOException e) {System.out.prin TLN ("Client file shutdown error");} catch (IOException e)}//finally}//public static void Main (string[] args)}//public class Clientsend