The goal is to develop a web server that when accessed via a web browser will return the HTTP request message that it receives.
I run the program from a virtual machine environment and access the server from my local machine. The code I have is below. When I type in my IP address while the server is running, I just get a Null Pointer Exception. Any guidance would be greatly appreciated.
import java.io.*;
import java.net.*;
import java.util.*;
public final class proj1 {
public static void main(String[] args) throws Exception{
int port = 9000;
ServerSocket socket = new ServerSocket(port);
while(true) {
Socket connection = socket.accept();
HttpRequest request = new HttpRequest(connection);
Thread thread = new Thread(request);
thread.start();
}
}
}
final class HttpRequest implements Runnable {
//Declare Variables
final static String CRLF = "\r\n";
Socket socket;
//Constructor
public HttpRequest(Socket socket) throws Exception {
this.socket = socket;
}
//Unimplemented Runnable Method
#Override
public void run() {
try {
processRequest();
} catch (Exception e) {
System.out.println(e);
}
}
private void processRequest() throws Exception {
//Reference Socket Input and Output Streams
InputStream is = socket.getInputStream();
DataOutputStream os = null;
//Input Stream Filters
BufferedReader br = new BufferedReader(null);
//Request Line of HTTP Request Message
String requestLine = br.readLine();
//Extract FileName From Request Line
StringTokenizer tokens = new StringTokenizer(requestLine);
tokens.nextToken();
String fileName = tokens.nextToken();
fileName = "." + fileName;
//Open Requested File
FileInputStream fis = null;
boolean fileExists = true;
try {
fis = new FileInputStream(fileName);
} catch (FileNotFoundException e) {
fileExists = false;
}
//Debug
System.out.println(requestLine);
String headerLine = null;
while ((headerLine = br.readLine()).length() != 0) {
System.out.println(headerLine);
}
//Construct Response Message
String statusLine = null;
String contentTypeLine = null;
String entityBody = null;
if (fileExists) {
statusLine = "statusLine";
contentTypeLine = "Content-Type: " + contentType(fileName) + CRLF;
} else {
statusLine = "HTTP/1.0 404 Not Found" + CRLF;
contentTypeLine = "Content-Type: text/html" + CRLF;
entityBody = "<HTML>" + "<HEAD><TITLE>Not Found</TITLE></HEAD>" + "<BODY>Not Found</BODY></HTML>";
}
//Send Lines
os.writeBytes(statusLine);
os.writeBytes(contentTypeLine);
os.writeBytes(CRLF);
//Send Entity Body
if (fileExists) {
sendBytes(fis, os);
fis.close();
} else {
os.writeBytes(entityBody);
}
//Close Streams and Sockets
os.close();
br.close();
socket.close();
}
private static void sendBytes(FileInputStream fis, OutputStream os) throws Exception {
byte[] buffer = new byte[1024];
int bytes = 0;
while ((bytes = fis.read(buffer)) != -1) {
os.write(buffer, 0, bytes);
}
}
private static String contentType(String fileName) {
if (fileName.endsWith(".htm") || fileName.endsWith(".html")) {
return "text/html";
}
return "application/octet-stream";
}
}
Exception in thread "main" java.net.BindException: Address already in use: JVM_Bind
at java.net.DualStackPlainSocketImpl.bind0(Native Method)
at java.net.DualStackPlainSocketImpl.socketBind(Unknown Source)
at java.net.AbstractPlainSocketImpl.bind(Unknown Source)
at java.net.PlainSocketImpl.bind(Unknown Source)
at java.net.ServerSocket.bind(Unknown Source)
at java.net.ServerSocket.<init>(Unknown Source)
at java.net.ServerSocket.<init>(Unknown Source)
at proj1.main(proj1.java:10)
That is the error code when I try to run the program in eclipse... When I run the code in my virtual machine, it runs fine but whenever I access the IP address of the server on my machine, I get no response message and a Null Pointer Exception on the virtual machine.
new BufferedReader(null) will always throw NullPointerException. What did you except?
By the way, this is always a bad idea:
try {
processRequest();
} catch (Exception e) {
System.out.println(e);
}
If you don't know what to do with the exception, at least re-throw it to retain the stack trace:
try {
processRequest();
} catch (Exception e) {
throw new RuntimeException(e);
}
This would have lead you to the line throwing the exception.
Related
I want to develop a HTTP Proxy ,
The code is here ;
When I run my code , I get this exception :
Started on: 9999
request for : /setwindowsagentaddr
Encountered exception: java.net.MalformedURLException: no protocol: /setwindowsagentaddr
package proxy;
import java.net.*;
import java.io.*;
public static void main(String[] args) throws IOException {
ServerSocket serverSocket = null;
boolean listenning = true;
// String host="192.168.1.10";
int port = 9999;
try{
port = Integer.parseInt(args[0]);
}catch(Exception e){
}
try{
serverSocket = new ServerSocket(port);
System.out.println("Started on: " + port);
}catch(Exception e){
// System.err.println("Could not listen on port: " + args[0]);
System.exit(0);
}
while(listenning){
new ProxyThread(serverSocket.accept()).start();
}
serverSocket.close();
}
}
and the ProxyThread here :
public class ProxyThread extends Thread {
private Socket socket = null;
private static final int BUFFER_SIZE = 32768;
public ProxyThread(Socket socket){
super("Proxy Thread");
this.socket=socket;
}
public void run(){
try {
DataOutputStream out = new DataOutputStream(socket.getOutputStream());
BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
String inputLine , outputLine;
int cnt = 0 ;
String urlToCall="";
//get request from client
// socket.getPort();
while((inputLine=in.readLine()) != null){
try{
StringTokenizer tok = new StringTokenizer(inputLine);
tok.nextToken();
}catch(Exception e){
break;
}
///parse the first line of the request to get url
if(cnt==0){
String [] tokens = inputLine.split(" ");
urlToCall = tokens[1];
System.out.println("request for : "+ urlToCall);
}
cnt++;
}
BufferedReader rd = null;
try{
//System.out.println("sending request
//to real server for url: "
// + urlToCall);
///////////////////////////////////
//begin send request to server, get response from server
URL url = new URL(urlToCall);
URLConnection conn = url.openConnection();
conn.setDoInput(true);
//not doing http post
conn.setDoOutput(false);
System.out.println("Type is : "+ conn.getContentType());
System.out.println("length is : "+ conn.getContentLength());
System.out.println("allow user interaction :"+ conn.getAllowUserInteraction());
System.out.println("content encoding : "+ conn.getContentEncoding());
System.out.println("type is : "+conn.getContentType());
// Get the response
InputStream is = null;
HttpURLConnection huc = (HttpURLConnection) conn;
if (conn.getContentLength() > 0) {
try {
is = conn.getInputStream();
rd = new BufferedReader(new InputStreamReader(is));
} catch (IOException ioe) {
System.out.println(
"********* IO EXCEPTION **********: " + ioe);
}
}
//end send request to server, get response from server
//begin send response to client
byte [] by = new byte[BUFFER_SIZE];
int index = is.read(by,0,BUFFER_SIZE);
while ( index != -1 )
{
out.write( by, 0, index );
index = is.read( by, 0, BUFFER_SIZE );
}
out.flush();
//end send response to client
}catch(Exception e){
//can redirect this to error log
System.err.println("Encountered exception: " + e);
//encountered error - just send nothing back, so
//processing can continue
out.writeBytes("");
}
//close out all resources
if (rd != null) {
rd.close();
}
if (out != null) {
out.close();
}
if (in != null) {
in.close();
}
if (socket != null) {
socket.close();
}
} catch (Exception e) {
e.printStackTrace();
}
}
How can I fix this exceptions?
So the error isn't lying, /setwindowsagentaddr isn't a valid url. How would it know what protocol to use?
Try using something like http://localhost:8080/setwindowsagentaddr
This is the class containing the main() method:
public class MultithreadedProxyServer {
public static void main(String[] args) throws IOException {
ServerSocket serverSocket = null;
boolean listening = true;
int port = 10000; //default
try {
port = Integer.parseInt(args[0]);
} catch (Exception e) {
//ignore me
System.out.println("gnore");
}
try {
serverSocket = new ServerSocket(port);
System.out.println("Started on: " + port);
} catch (IOException e) {
System.err.println("Could not listen on port: " + args[0]);
System.exit(-1);
}
while (listening) {
new ProxyThread(serverSocket.accept()).start();
}
serverSocket.close();
}
}
And this is the ProxyThread class:
public class ProxyThread extends Thread {
private Socket socket = null;
private static final int BUFFER_SIZE = 32768;
public ProxyThread(Socket socket) {
super("ProxyThread");
this.socket = socket; //initialzed my parent before you initalize me
}
public void run() {
//get input from user
//send request to server
//get response from server
//send response to user
System.out.println("run");
try {
DataOutputStream out =
new DataOutputStream(socket.getOutputStream());
BufferedReader in = new BufferedReader(
new InputStreamReader(socket.getInputStream()));
String inputLine, outputLine;
int cnt = 0;
String urlToCall = "";
///////////////////////////////////
//begin get request from client
while ((inputLine = in.readLine()) != null) {
try {
StringTokenizer tok = new StringTokenizer(inputLine);
tok.nextToken();
} catch (Exception e) {
System.out.println("break");
break;
}
//parse the first line of the request to find the url
if (cnt == 0) {
String[] tokens = inputLine.split(" ");
urlToCall = tokens[1];
//can redirect this to output log
System.out.println("Request for : " + urlToCall);
}
cnt++;
}
//end get request from client
///////////////////////////////////
BufferedReader rd = null;
try {
//System.out.println("sending request
//to real server for url: "
// + urlToCall);
///////////////////////////////////
//begin send request to server, get response from server
URL url = new URL(urlToCall);
URLConnection conn = url.openConnection();
conn.setDoInput(true);
//not doing HTTP posts
conn.setDoOutput(false);
//System.out.println("Type is: "
//+ conn.getContentType());
//System.out.println("content length: "
//+ conn.getContentLength());
//System.out.println("allowed user interaction: "
//+ conn.getAllowUserInteraction());
//System.out.println("content encoding: "
//+ conn.getContentEncoding());
//System.out.println("content type: "
//+ conn.getContentType());
// Get the response
InputStream is = null;
HttpURLConnection huc = (HttpURLConnection)conn;
if (conn.getContentLength() > 0) {
is = conn.getInputStream();
rd = new BufferedReader(new InputStreamReader(is));
}
//end send request to server, get response from server
///////////////////////////////////
///////////////////////////////////
//begin send response to client
byte by[] = new byte[ BUFFER_SIZE ];
int index = is.read( by, 0, BUFFER_SIZE );
while ( index != -1 )
{
out.write( by, 0, index );
index = is.read( by, 0, BUFFER_SIZE );
}
out.flush();
//end send response to client
///////////////////////////////////
} catch (Exception e) {
//can redirect this to error log
System.err.println("Encountered exception: " + e);
//encountered error - just send nothing back, so
//processing can continue
out.writeBytes("");
}
//close out all resources
if (rd != null) {
rd.close();
}
if (out != null) {
out.close();
}
if (in != null) {
in.close();
}
if (socket != null) {
socket.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
I have copy-pasted the above code from the internet, however I am having difficulties running it.
To answer the question from the post title, the run() method from ProxyThread class is called by JVM, after the thread has been started new ProxyThread(serverSocket.accept()).start(); and it usually contains the actual work that a thread should performed (in this case, it handles whatever the server socket receives and it accepts a connection from a client).
The moment when JVM calls run() method cannot be controlled by the programmer, but is after the thread has been started.
run() method is never called explicitly by the programmer.
In my client server application, client sends some commands and the server gives the results back. Now the problem is when the client tries to download a file from the server, by using GET filename command. The program works fine, even it can doesnload the file correctly, but the problem is in the server side's command prompt there is always a null pointer exception error remains. And it happens immediately after I enter the GET command. Error:
Second issue appears when I remove fis.close(); line in serverside. It shows another trace error in the server side: Error:
This is the complete project I am working on:
ClientSide:
package clientside;
import java.io.*;
import java.net.*;
import java.util.Scanner;
public class ClientSide {
private static Socket socket;
private static PrintWriter outputToServer;
private static BufferedReader inputFromServer;
private static InputStream is;
private static FileOutputStream fos;
private static final int PORT = 8000;
private static final String SERVER = "85.197.159.45";
boolean Connected;
DataInputStream serverInput;
public static void main(String[] args) throws InterruptedException {
String server = "localhost";
int port = PORT;
if (args.length >= 1) {
server = args[0];
}
if (args.length >= 2) {
port = Integer.parseInt(args[1]);
}
new ClientSide(server, port);
}
public ClientSide(String server, int port) {
try {
socket = new Socket(server, port);
serverInput = new DataInputStream(socket.getInputStream());
outputToServer = new PrintWriter(socket.getOutputStream(), true);
inputFromServer = new BufferedReader(new InputStreamReader(socket.getInputStream()));
System.out.println("Client is connected! ");
Connected = true;
String line = null;
Scanner sc = new Scanner(System.in);
System.out.print("Type command: ");
while (sc.hasNextLine()) {
String request = sc.nextLine();
if (request.startsWith("exit")) {
outputToServer.println(request);
System.out.println("Application exited!");
//outputToServer.flush();
break;
} else if (request.startsWith("pwd")) {
outputToServer.println(request);
outputToServer.flush();
} else if (request.startsWith("list")) {
outputToServer.println(request);
outputToServer.flush();
} else if (request.startsWith("GET")) {
System.out.print("\r\n");
outputToServer.println(request);
outputToServer.flush();
}
while (Connected) {
line = inputFromServer.readLine();
System.out.println(line);
if (line.isEmpty()) {
Connected = false;
if (inputFromServer.ready()) {
System.out.println(inputFromServer.readLine());
}
}
if (line.startsWith("Status 400")) {
while (!(line = inputFromServer.readLine()).isEmpty()) {
System.out.println(line);
}
break;
}
if (request.startsWith("GET")) {
File file = new File(request.substring(4));
is = socket.getInputStream();
fos = new FileOutputStream(file);
byte[] buffer = new byte[socket.getReceiveBufferSize()];
serverInput = new DataInputStream(socket.getInputStream());
//int bytesReceived = 0;
byte[] inputByte = new byte[4000];
int length;
while ((length = serverInput.read(inputByte, 0, inputByte.length)) > 0) {
fos.write(inputByte, 0, length);
}
/*
while ((bytesReceived = is.read(buffer)) >=0) {
//while ((bytesReceived = is.read(buffer))>=buffer) {
fos.write(buffer, 0, bytesReceived);
}
*/
request = "";
fos.close();
is.close();
}
}
System.out.print("\nType command: ");
Connected = true;
}
outputToServer.close();
inputFromServer.close();
socket.close();
} catch (IOException e) {
System.err.println(e);
}
}
}
ServerSide:
package serverside;
import java.io.*;
import java.net.*;
import java.util.Arrays;
public class ServerSide {
private BufferedReader inputFromClient;
private PrintWriter outputToClient;
private FileInputStream fis;
private OutputStream os;
private static final int PORT = 8000;
private ServerSocket serverSocket;
private Socket socket;
public static void main(String[] args) {
int port = PORT;
if (args.length == 1) {
port = Integer.parseInt(args[0]);
}
new ServerSide(port);
}
private boolean fileExists(File[] files, String filename) {
boolean exists = false;
for (File file : files) {
if (filename.equals(file.getName())) {
exists = true;
}
}
return exists;
}
public ServerSide(int port) {
// create a server socket
try {
serverSocket = new ServerSocket(port);
} catch (IOException ex) {
System.out.println("Error in server socket creation.");
System.exit(1);
}
while (true) {
try {
socket = serverSocket.accept();
os = socket.getOutputStream();
outputToClient = new PrintWriter(socket.getOutputStream());
inputFromClient = new BufferedReader(new InputStreamReader(socket.getInputStream()));
while (true) {
String request = inputFromClient.readLine();
if (!request.startsWith("exit") && !request.startsWith("pwd") && !request.startsWith("list") && !request.startsWith("GET")) {
outputToClient.println("Wrong request\r\n"
+ "\r\n");
} else if (request.startsWith("exit")) {
break;
} else if (request.startsWith("pwd")) {
File file = new File(System.getProperty("user.dir"));
outputToClient.print("Status OK\r\n"
+ "Lines 1\r\n"
+ "\r\n"
+ "Working dir: " + file.getName() + "\r\n");
} else if (request.startsWith("list")) {
File file = new File(System.getProperty("user.dir"));
File[] files = file.listFiles();
outputToClient.print("Status OK\r\n"
+ "Files " + files.length + "\r\n"
+ "\r\n"
+ Arrays.toString(files).substring(1, Arrays.toString(files).length() - 1) + "\r\n");
} else if (request.startsWith("GET")) {
String filename = request.substring(4);
File file = new File(System.getProperty("user.dir"));
File[] files = file.listFiles();
if (fileExists(files, filename)) {
file = new File(filename);
int fileSize = (int) file.length();
outputToClient.printf("Status OK\r\nSize %d Bytes\r\n\r\nFile %s Download was successfully\r\n",
fileSize, filename);
outputToClient.flush();
try (FileInputStream fis = new FileInputStream(file)) {
byte[] buffer = new byte[(1 << 7) - 1];
int bytesRead = 0;
while ((bytesRead = fis.read(buffer)) != -1) {
os.write(buffer, 0, bytesRead);
}
}
os.close();
fis.close();//NPE is happening here.
} else {
outputToClient.print("Status 400\r\n"
+ "File " + filename + " not found\r\n"
+ "\r\n");
outputToClient.flush();
}
}
outputToClient.flush();
}
} catch (IOException e) {
System.err.println(e);
}
finally{
os.close();
}
}
}
}
UPDATE: Even if I remove the fis.close(); line from the server side, it shows java.net.SocketException: socket closed error.
The original problem is that you are using a try-with-resources block with an assigned variable with the same name as one of your class member variables. Removing the following line will remove the NPE:
fis.close();
The SocketException is being caused by the line:
os.close();
According to the documentation of Socket::getOutputStream:
Closing the returned OutputStream will close the associated socket.
Therefore, moving the line os = socket.getOutputStream(); to just below the line socket = serverSocket.accept(); line, and also moving os.close() to a finally block after your final catch block should solve this issue.
The socket represented by fis is null.
To correct, use this:
if (fis != null) fis.close;
try (FileInputStream fis = new FileInputStream(file))
In this line you are creating a new FileInputStream and using it, and it is not your FileInputStream field, declared before. This fis exists only on the "try" block. When you try to close your fis os.close(); you are trying to close your fis field, not the fis declared in the try.
Use this, instead:
try (fis = new FileInputStream(file)). With this you are instantiating a new FileInputStream in your field, not in a new variable.
I run my java webserver on port 6799
My directory has a txt.txt file and pdf.pdf file
When I give localhost:6799/txt.txt, it gives perfect output saying
GET /txt.txt HTTP/1.1HTTP/1.0 200 OK
Content-type: text/plain
This is a very simple text file
But when I give localhost:6799/pdf.pdf from browser, it gives java.lang.NullPointerException
This is my code
import java.net.*;
public final class WebServer {
public static void main(String args[]) throws Exception {
int port = 6799;
System.out.println("\nListening on port " + port);
ServerSocket listen = new ServerSocket(port);
while (true) {
Socket socket = listen.accept();
HttpRequest request = new HttpRequest(socket);
Thread thread = new Thread(request);
thread.start();
}
}
}
--
import java.io.*;
import java.net.*;
import java.util.StringTokenizer;
public final class HttpRequest implements Runnable {
final String CRLF = "\r\n";
Socket socket;
public HttpRequest(Socket socket) throws Exception {
this.socket = socket;
}
#Override
public void run() {
try {
processRequest();
} catch (Exception e) {
System.out.println(e);
}
}
private void processRequest() throws Exception {
BufferedReader br;
DataOutputStream dos;
try (InputStream is = socket.getInputStream()) {
br = new BufferedReader(new InputStreamReader(is));
String requestline = br.readLine();
System.out.println("\n" + requestline);
String headerLine = null;
while ((headerLine = br.readLine()).length() != 0) {
System.out.println(headerLine);
}
dos = new DataOutputStream(socket.getOutputStream());
dos.writeBytes(requestline);
StringTokenizer tokens = new StringTokenizer(requestline);
tokens.nextToken(); // skip over the method, which should be "GET"
String fileName = tokens.nextToken();
// Prepend a "." so that file request is within the current directory.
fileName = "." + fileName;
FileInputStream fis = null;
boolean fileExists = true;
try {
fis = new FileInputStream(fileName);
} catch (FileNotFoundException e) {
fileExists = false;
}
String statusLine = null;
String contentTypeLine = null;
String entityBody = null;
if (fileExists) {
statusLine = "HTTP/1.0 200 OK" + CRLF;
contentTypeLine = "Content-type: " + contentType(fileName) + CRLF;
} else {
statusLine = "HTTP/1.0 404 Not Found" + CRLF;
//contentTypeLine = "Content-type: " + "text/html" + CRLF;
entityBody = "<HTML>"
+ "<HEAD><TITLE>Not Found</TITLE></HEAD>"
+ "<BODY>Not Found</BODY></HTML>";
}
dos.writeBytes(statusLine);
dos.writeBytes(contentTypeLine);
dos.writeBytes(CRLF);
if (fileExists) {
sendBytes(fis, dos);
fis.close();
} else {
dos.writeBytes(entityBody);
}
}
br.close();
dos.close();
socket.close();
}
private void sendBytes(FileInputStream fis, DataOutputStream dos) throws IOException {
byte[] buffer = new byte[4096];
int bytes = 0;
while ((bytes = fis.read(buffer)) != -1) {
dos.write(buffer, 0, bytes);
}
}
private String contentType(String fileName) {
if (fileName.endsWith(".htm") || fileName.endsWith(".html")) {
return "text/html";
}
if (fileName.endsWith(".jpg") || fileName.endsWith(".jpeg")) {
return "image/jpeg";
}
if (fileName.endsWith(".gif")) {
return "image/gif";
}
if (fileName.endsWith(".txt")) {
return "text/plain";
}
if (fileName.endsWith(".pdf")) {
return "application/pdf";
}
return "application/octet-stream";
}
}
STACK TRACE
java.lang.NullPointerException
at java.io.DataOutputStream.writeBytes(DataOutputStream.java:274)
at HttpRequest.processRequest(HttpRequest.java:65)
at HttpRequest.run(HttpRequest.java:20)
at java.lang.Thread.run(Thread.java:724)
At least one issue is this code:
while ((headerLine = br.readLine()).length() != 0) {
System.out.println(headerLine);
}
BufferedReader will return null at the end of the stream, so calling .length() on a null object will yield a NullPointerException.
A more idiomatic way to write this is:
while ((headerLine = br.readLine()) != null && headerLine.length() != 0) {
System.out.println(headerLine);
}
...which takes advantage of short-circuit logic to not evaluate the second condition if the result of (headerLine = br.readLine()) is null.
It is happening because for some reason you have toggled comment on the following line:
//contentTypeLine = "Content-type: " + "text/html" + CRLF;
Untoggle it and you're good!
I'm creating a p2p application in Java for file sharing. Each peer node will be running on my machine on a different port and listen for a request. but the problem I'm running into is when an instance of PeerNode is created my code runs into an infinite loop. Following is my code for PeerNode. Is this how I should create each node and have them listen for incoming requests?
Following code represents one peer node:
public class PeerNode
{
private int port;
private ArrayList<PeerNode> contacts;
PeerNode preNode;
PeerNode postNode;
private String directoryLocation = "";
PeerNode(int port)
{
this.port = port;
this.setDirectoryLocation( port+"");
startClientServer( port );
}
private void sendRequest(String fileName, String host, int port) throws UnknownHostException, IOException
{
Socket socket = new Socket(host, port);//machine name, port number
PrintWriter out = new PrintWriter( socket.getOutputStream(), true );
out.println(fileName);
out.close();
socket.close();
}
private void startClientServer( int portNum )
{
try
{
// Establish the listen socket.
ServerSocket server = new ServerSocket( 0 );
System.out.println("listening on port " + server.getLocalPort());
while( true )
{
// Listen for a TCP connection request.
Socket connection = server.accept();
// Construct an object to process the HTTP request message.
HttpRequestHandler request = new HttpRequestHandler( connection );
// Create a new thread to process the request.
Thread thread = new Thread(request);
// Start the thread.
thread.start();
System.out.println("Thread started for "+ portNum);
}
}
catch (Exception e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
And following class creates all the nodes and connects them:
public class MasterClientServer
{
public static void main( String [] args )
{
int count = 10;
ArrayList<PeerNode> arrayOfNodes = createNodes( count );
}
public static ArrayList<PeerNode> createNodes( int count)
{
System.out.println("Creating a network of "+ count + " nodes...");
ArrayList< PeerNode > arrayOfNodes = new ArrayList<PeerNode>();
for( int i =1 ; i<=count; i++)
{
arrayOfNodes.add( new PeerNode( 0 ) ); //providing 0, will take any free node
}
return arrayOfNodes;
}
}
public class HttpRequestHandler implements Runnable
{
final static String CRLF = "\r\n";
Socket socket;
public HttpRequestHandler(Socket socket) throws Exception
{
this.socket = socket;
}
#Override
public void run()
{
try
{
processRequest();
}
catch (Exception e)
{
System.out.println(e);
}
}
/*
* Gets a request from another node.
* Sends the file to the node if available.
*/
private void processRequest() throws Exception
{
/*DataOutputStream os = new DataOutputStream(socket.getOutputStream());
InputStream is = socket.getInputStream();
BufferedReader br = new BufferedReader(new InputStreamReader(is));
// Get the request line of the HTTP request message.
String requestLine = br.readLine();
// Extract the filename from the request line.
// In Get request, the second token is the fie name
String[] tokens = requestLine.split(" ");
String fileName = tokens[1];
// Prepend a "." so that file request is within the current directory.
fileName = "." + fileName;
// Open the requested file.
FileInputStream fis = null;
boolean fileExists = true;
try
{
fis = new FileInputStream(fileName);
}
catch (FileNotFoundException e)
{
fileExists = false;
}
// construct the response Message
// Construct the response message.
String statusLine = null;
String contentTypeLine = null;
String entityBody = null;
if (fileExists)
{
statusLine = "HTTP/1.1 200 OK" + CRLF;
contentTypeLine = "Content-Type: " + contentType(fileName) + CRLF;
}
else
{
statusLine = "HTTP/1.1 404 Not Found" + CRLF;
contentTypeLine = "Content-Type: text/html" + CRLF;
entityBody = "<HTML><HEAD><TITLE>404 Not Found</TITLE></HEAD><BODY>Error 404: Page Not Found</BODY></HTML>";
}
// Send the status line.
os.writeBytes(statusLine);
// Send the content type line.
os.writeBytes(contentTypeLine);
// Send a blank line to indicate the end of the header lines.
os.writeBytes(CRLF);
// Send the entity body.
if (fileExists) {
sendBytes(fis, os);
fis.close();
} else {
os.writeBytes(entityBody);
}
// Close streams and socket.
os.close();
br.close();
socket.close();
}
private static void sendBytes(FileInputStream fis, OutputStream os)
throws Exception
{
// Construct a 1K buffer to hold bytes on their way to the socket.
byte[] buffer = new byte[1024];
int bytes = 0;
// Copy requested file into the socket's output stream.
while ((bytes = fis.read(buffer)) != -1) {
os.write(buffer, 0, bytes);
}*/
}
private static String contentType(String fileName)
{
if (fileName.endsWith(".htm") || fileName.endsWith(".html"))
{
return "text/html";
}
if (fileName.endsWith(".jpg") || fileName.endsWith(".jpeg"))
{
return "image/jpeg";
}
if (fileName.endsWith(".gif")) {
return "image/gif";
}
if (fileName.endsWith(".ram") || fileName.endsWith(".ra"))
{
return "audio/x-pn-realaudio";
}
return "application/octet-stream";
}
}
Your PeerNode constructor never returns since it is busy accepting new connections. Hence your loop in createNodes only creates the first PeerNode instance. You can solve this by calling startClientServer in a new thread:
new Thread(new Runnable() {
public void run() {
startClientServer( port );
}
}.start();