I have a server that returns a file photo.png for a client, the server is running correctly considering the client as a browser when i introduce this link localhost:5555/photo.png i dont get the picture i get this:
\89PNG
\00\00\00
IHDR\00\00\00\00\00\00\00\91\F9\00\00\00gAMA\00\00\B1\8F\FCa\00\00\00sRGB\00\AE\CE\E9\00\00\00PLTELiq\EA\F2\F7\F2\F4\F8\FB\EF\EF\E9\F1\F7\EA\F2\F8\EC\F3\F8\FC\EC\EB\FB\ED\EE\E4\EF\F7\FB\EC\EC\FB\ED\ED\FB\ED\ED\ED\F4\F9\FB\EF\EF\FD\ED\ED\EB\EB\EB\FB\EB\EB\F9\EE\EF\FA\EB\EB\EE\F4\F8\F2\F2\F2\FB\E9\E9\E9\F1\F8\EA\F1\F8\EC\F3\F8\FB\E9\EA\E6\F0\F6\E7\F1\F7\FC\EF\EF\EA\F1\F6\EF\EF\EF\ED\F3\F7\ED\F3\F8\E7\F0\F7\FA\EE\EE\FA\E9\E9\EA\F0\F8\ED\F2\F9\EA\F3\F9\F3\F2\F4\FC\EC\EB\E1"o\B6\E0"\E1!\E0!\E1! n\B5\E0 \E0k\B4\00f\B2n\B6\E0m\B5 n\B6\00g\B2\E0\E0\DFj\B3\00a\AF\DF\00e\B1l\B4\00i\B3\DF\E0!l\B5\00h\B2\DF\00`\AE m\B5\E0\E1"\DF\DF\00c\B0\E47:\DF
\E2'*\E0\E5:<\DE \DE\DF\00d\B0\00_\AE\F2\9D\9F\DE
y\BB\DF ........
This is the code or text behind the image photo.png but what it should displayed is:
photo.ong
The same happens when i want a PDF file i get the code and not the file...
import java.io.*;
import java.net.*;
public class Server {
public static void main (String[] args){
Socket socket;
ServerSocket serverSocket;
BufferedReader in = null;
PrintWriter out = null;
BufferedInputStream bis;
BufferedOutputStream bos;
try{
serverSocket=new ServerSocket(5555);
socket = serverSocket.accept();
out = new PrintWriter(socket.getOutputStream(), true);
in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
String input, output;
input = in.readLine(); //(1)
out.println("Server: Connected. Input from Client:"+input); //(2)
input = in.readLine(); //(1)
out.println("Server: I am ready to recieve file. Input from Client:"+input); //(2)
bis = new BufferedInputStream(socket.getInputStream());
bos = new BufferedOutputStream(new FileOutputStream("photo.png"));
int length = Integer.parseInt(input);
int i=0;
int IN=0;
byte[] receivedData = new byte[1000];
while ((IN = bis.read(receivedData)) != length){ //in = int; receivedData = byte[]
bos.write(receivedData,0,IN);
}
}
catch(IOException e){
e.printStackTrace();
}
}
}
This server was implemented by http://www.coderanch.com
I think you're trying to perform File IO operations on an image. See the following:
How to make ImageIO read from InputStream :Java
I have a server that displays what the user asks for from the browser, I am using linux and when i run the server and ask for a file like Image.png using this link localhost:9999/Image.png on FireFox i get this message:
The image "localhost:9999/Image.png" cannot be displayed because it
contains errors.
But when i change the variable fileName to an HTML file it works perfectly and i can visualize the html page.
What am I doing wrong??
This is my server:
import java.io.*;
import java.net.*;
import java.util.Scanner;
public class Server {
public static void main(String args[]) throws IOException {
// Declarem les variables a utilitzar
ServerSocket serverSocket = null;
Socket socket = null;
InputStream inS = null;
OutputStream outS = null;
try
{
serverSocket = new ServerSocket(9999);
while(true)
{
socket= serverSocket.accept();
inS = socket.getInputStream();
outS = socket.getOutputStream();
try{
BufferedReader br = new BufferedReader(new InputStreamReader(inS));
BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(outS));
System.out.println("THis is what the user wants = " + br.readLine());
String fileName = "Image.png";
String extension= "";
int i = fileName.lastIndexOf('.');
if (i > 0) {
extension = fileName.substring(i+1);
}
String dataReturn = "";
if(extension.equals("png"))
{
bw.write("HTTP/1.0 200 OK\r\n");
bw.write("Content-Type: image/png\r\n");
bw.write("\r\n");
FileReader myFilepng = new FileReader(fileName);
Scanner scanner1 = new Scanner(myFilepng);
dataReturn = "";
while(scanner1.hasNextLine()) {
dataReturn = scanner1.nextLine();
System.out.println(dataReturn);
bw.write(dataReturn);
}
scanner1.close();
}else{
if(extension.equals("html"))
{
bw.write("HTTP/1.0 200 OK\r\n");
bw.write("Content-Type: text/html\r\n");
bw.write("\r\n");
bw.write("<TITLE>"+fileName+"/TITLE>");
FileReader myFile = new FileReader(fileName);
Scanner scanner = new Scanner(myFile);
dataReturn = "";
while(scanner.hasNextLine()) {
dataReturn = scanner.nextLine();
System.out.println(dataReturn);
bw.write(dataReturn);
}
scanner.close();
}
}
bw.close();
}catch(Exception e)
{
}
}
}catch (IOException e) {
System.out.println(e);
}
inS.close();
outS.close();
socket.close();
}
}
You are not writing the contents of your png file to your bw BufferedWriter. Instead you are only sending the header of the response to the client. As you are indicating your response is a png image and there is no data, your browser is telling you the image contains errors (in fact, it does not contains nothing at all).
Open the png filename, write the data to your "bw" buffer to send it to the client. That should be enough.
Edit:
To to that, try the following code for your "if" is image:
if(extension.equals("png"))
{
File file = new File(fileName);
FileInputStream fis = new FileInputStream(file);
byte[] data = new byte[(int) file.length()];
fis.read(data);
fis.close();
DataOutputStream binaryOut = new DataOutputStream(outS);
binaryOut.writeBytes("HTTP/1.0 200 OK\r\n");
binaryOut.writeBytes("Content-Type: image/png\r\n");
binaryOut.writeBytes("Content-Length: " + data.length);
binaryOut.writeBytes("\r\n\r\n");
binaryOut.write(data);
binaryOut.close();
}
Note the use of a binary stream in comparison to the text stream you use in case of html.
First I apologize for my English. I'm trying to make a Client-Server connection in Java but I have a problem getting response from the server. When I close the server first, the client will receive a response from the server. If I close the client first, nothing happens.
Here is the code of the server:
BufferedReader input = new BufferedReader(new InputStreamReader(socket.getInputStream(),"8859_1"),1024);
DataOutputStream sendToClient= new DataOutputStream(socket.getOutputStream());
StringBuffer sb = new StringBuffer();
sb.append(input.readLine());
if(sb.toString().equalsIgnoreCase("lamoyenne")) {
System.out.println(Esclave.moyenneTarif());
sendToClient.writeBytes(String.valueOf(Esclave.moyenneTarif()));
}
if(sb.toString().equalsIgnoreCase("nombrelieuentre100et200")) {
System.out.println(Esclave.nombreLieuEntre100et200());
sendToClient.writeBytes(String.valueOf(Esclave.nombreLieuEntre100et200()));
}
else {
System.out.println(Esclave.tarifParLieu(sb.toString()));
sendToClient.writeBytes(String.valueOf(Esclave.tarifParLieu(sb.toString())));
}
Here is the code for the client:
System.out.println("Type in: ");
this.connexion = new Socket(InetAddress.getLocalHost(),44000);
Writer output = new OutputStreamWriter(connexion.getOutputStream(), "8859_1");
BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
this.line = in.readLine();
//DataOutputStream sendToServer = new DataOutputStream(connexion.getOutputStream(),"8859_1");
//sendToServer.writeBytes(this.line+'\n');
output.write(this.line);
output.flush();
connexion.shutdownOutput();
BufferedReader inFromServer = new BufferedReader(new InputStreamReader(connexion.getInputStream()));
String temp = inFromServer.readLine();
System.out.println("FROM SERVER: "+ temp);
I'm new at Java and have been having some issues while passing a variable from one class to another main class.
A little about the program -
I have one main class called "Server.java" and another main class called "Client.java"
This is a simple TCP Server-client program written in java. The server class is executed first so it can accept connection from the client, which is executed second.
Once the client is connected to the server, the client specifies the name of the file it wishes to receive from the server by typing, for instance, "alice.txt" and then the server sends the file with that name in it's directory to the client.
Where I'm stuck -
I'm only able to receive file on the client side if I hard code the name of the file first in the server (check the code below). I wish to take the file name from the client side and pass to the Server class so the code works for all the files and not just one, which was hard coded.
Any help is appreciated :)
Server.java
import java.io.*;
import java.net.*;
class Server
{
public static void main(String argv[]) throws Exception
{
//beginning of the try method
try
{
//create a new serversocket object with port no 6789
ServerSocket welcomeSocket = new ServerSocket(6789);
//while loop
while(true)
{
//create a new socket object and accept the connection and it waits for any connection from client
Socket connectionSocket = welcomeSocket.accept();
//display confirmation to the user
System.out.println("Connection accepted!");
System.out.println("File request recevied!");
//specify the file the server wants to send
File myFile = new File("alice.txt");
//THIS IS WHERE THE FILE FROM THE CLIENT IS HARD-CODED. I AM TRYING TO REPLACE THE FILE NAME WITH A VARIABLE THAT WAS PASSED FROM THE CLIENT SIDE
//get the byte array length of the file
byte [] bArray = new byte [(int)myFile.length()];
//open a new file object
FileInputStream f = new FileInputStream(myFile);
//new buffered input stream object
BufferedInputStream bs = new BufferedInputStream(f);
//read function of the inputput stream
bs.read(bArray, 0, bArray.length);
//declare new output strea object
OutputStream os = connectionSocket.getOutputStream();
//display messages to the users
System.out.println("Okay, sending the file now.");
//write the file
os.write(bArray, 0, bArray.length);
//flush the file
os.flush();
//close the connection
connectionSocket.close();
//display confirmation message to the user
System.out.println("File was successfully sent!");
}
}
catch(Exception e)
{
System.out.println(e.getMessage());
}
}
}
Client.java
import java.io.*;
import java.net.*;
import java.util.*;
class Client
{
public static void main(String argv[]) throws Exception
{
try
{
//declare scanner object
Scanner s = new Scanner(System.in);
//display a message to the user
System.out.println("Enter the file name you wish to request");
//read the user input
String textFileName = s.nextLine();
//declare a new Socket object and specify the host name and the port number
Socket clientSocket = new Socket("localhost", 6789);
//make a byte array in which the transmitted file will be broken down into and sent
byte [] bArray = new byte[10000000];
//create new inputstream object and set it to the input stream from the client
InputStream is = clientSocket.getInputStream();
//open new fileinput object
FileOutputStream fos = new FileOutputStream(textFileName);
//get the value from the fileoutputstream to bufferedoutput stream
BufferedOutputStream bos = new BufferedOutputStream(fos);
//read function of the inputsteam object
int readFile = is.read(bArray,0,bArray.length);
//assign readfile to endile
int endFile = readFile;
do
{
readFile = is.read(bArray, endFile, (bArray.length-endFile));
if(readFile >= 0)
{
endFile = endFile + readFile;
}
}while(readFile > -1);
//write file
bos.write(bArray, 0, endFile);
//show the message to the user
System.out.println("File " + textFileName + " was successfully received!");
//flush the file
bos.flush();
//close the file
bos.close();
//close the socket
clientSocket.close();
///
}
catch(Exception e)
{
System.out.println(e.getMessage());
}
}
}
How I would do :
PS : this has not been tested but the principle is here..
Server.java
import java.io.*;
import java.net.*;
class Server
{
public static void main(String argv[]) throws Exception
{
//beginning of the try method
try
{
//create a new serversocket object with port no 6789
ServerSocket welcomeSocket = new ServerSocket(6789);
//while loop
while(true)
{
//create a new socket object and accept the connection and it waits for any connection from client
Socket connectionSocket = welcomeSocket.accept();// TODO - Make a new thread after the connection is accepted
//display confirmation to the user
System.out.println("Connection accepted!");
// Recover the fileName from client
String fileName = "";
InputStream iS = connectionSocket.getInputStream();
InputStreamReader iSR = new InputStreamReader(iS);
BufferedReader bR = new BufferedReader(iSR);
fileName = bR.readLine();
System.out.println("File request received : " + fileName);
// Recover the file's byte array
File myFile = new File(fileName);
byte[] bArray = new byte[(int)myFile.length()];
FileInputStream f = new FileInputStream(myFile);
BufferedInputStream bs = new BufferedInputStream(f);
bs.read(bArray, 0, bArray.length);
//display messages to the users
System.out.println("Okay, sending the file now.");
//declare new output strea object
OutputStream os = connectionSocket.getOutputStream();
os.write(bArray, 0, bArray.length);
os.flush();
//close the connection
connectionSocket.close();
//display confirmation message to the user
System.out.println("File was successfully sent!");
}
}
catch(Exception e)
{
System.out.println(e.getMessage());
}
}
}
Client.java
import java.io.*;
import java.net.*;
import java.util.*;
class Client
{
public static void main(String argv[]) throws Exception
{
try
{
//declare scanner object
Scanner s = new Scanner(System.in);
//display a message to the user
System.out.println("Enter the file name you wish to request");
//read the user input
String textFileName = s.nextLine();
//declare a new Socket object and specify the host name and the port number
Socket clientSocket = new Socket("localhost", 6789);
// Send the filename via the connection
OutputStream oS = clientSocket.getOutputStream();
BufferedWriter bW = new BufferedWriter(new OutputStreamWriter(oS));
bW.write(textFileName);
//make a byte array in which the transmitted file will be broken down into and sent
byte[] bArray = new byte[10000000];
//create new inputstream object and set it to the input stream from the client
InputStream is = clientSocket.getInputStream();
//open new fileinput object
FileOutputStream fos = new FileOutputStream(split[1]);
//get the value from the fileoutputstream to bufferedoutput stream
BufferedOutputStream bos = new BufferedOutputStream(fos);
//read function of the inputsteam object
int readFile = is.read(bArray,0,bArray.length);
//assign readfile to endile
int endFile = readFile;
do
{
readFile = is.read(bArray, endFile, (bArray.length-endFile));
if(readFile >= 0)
{
endFile = endFile + readFile;
}
}while(readFile > -1);
//write file
bos.write(bArray, 0, endFile);
//show the message to the user
System.out.println("File " + textFileName + " was successfully received!");
//flush the file
bos.flush();
//close the file
bos.close();
//close the socket
clientSocket.close();
///
}
catch(Exception e)
{
System.out.println(e.getMessage());
}
}
}
As per your code, once connection established, client expecting something from server using InputStream, and server sending data to client using OutputStream. but you have to do in this way, once connection established, in client code, write filename to server using OutputStream and then read data from server, similarly, in server side first read something from client and then write something to client as you did.
I use a PrintWriter out object. I write data out.println(some data) and close it with a out.close
URL url = new URL(myurl);
URLConnection connection = null;
PrintWriter out = null; BufferedReader br = null; connection = url.openConnection(); connection.setDoOutput(true);
out = new PrintWriter(new OutputStreamWriter(connection.getOutputStream()),true);
while(iterations) {
//print data on writer
out.println(object);
}
//closig print writer
out.flush();
out.close();
//Response from server
br = new BufferedReader(new InputStreamReader(connection.getInputStream())); // Get Exception in //this line EOF Exception
String temp;
while(temp = br.readLine() !=null) {
//do something
}
br.close();
URL url = new URL(myurl);
URLConnection connection = null;
PrintWriter out = null; BufferedReader br = null; connection = url.openConnection(); connection.setDoOutput(true);
out = new PrintWriter(new OutputStreamWriter(connection.getOutputStream()),true);
while(iterations)
{
//print data on writer
out.println(object);
}
//closig print writer
out.flush();
//Response from server
br = new BufferedReader(new InputStreamReader(connection.getInputStream())); // Get Exception in //this line EOF Exception
String temp;
while(temp = br.readLine() !=null)
{ //do something }
out.close();
Have a look at the code, you just had to put out.close instead of br.close at the end.