I am trying to make another thread wait in below code but my current thread itself is waiting infinitely. Below are two java classes Server.java that spawns runnable instances of ServerService.java. When such running instance of "ServerService.java" call enqueue method of Server.java.Server.java should make such callee thread wait. But seems my Server.java Thread itself waits infinitely
Server.java
import java.io.DataInputStream;
import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Queue;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
public class Server{
private ServerSocket server=null;
public static Map<Socket,String> clientsConnected=null;
public static Map<Socket,Runnable> clientsAndThreads=null;
public static ExecutorService executor=null;
public static List<Runnable> requestQueue=null;
public static Map<Runnable,Integer> threadAndRespectiveTime=null;
/*
* Contructor
*/
Server(){
clientsConnected=new HashMap<Socket,String>();
clientsAndThreads=new HashMap<Socket,Runnable>();
threadAndRespectiveTime=new HashMap<>();
requestQueue=new ArrayList<>();
}
/*
* Accepts connections from clients continually till the server is UP(max 10 clients)
*/
public void acceptConnection(){
try{
executor=Executors.newFixedThreadPool(10);
new Thread(new Runnable() {
@Override
public void run() {
Socket client=null;
while(server.isBound()){
try{
client=server.accept();
DataInputStream di= new DataInputStream(client.getInputStream());
String msg=di.readUTF();
clientsConnected.put(client, getMessage(msg));
ServerWindow.write(msg);
Runnable service= new ServerService(client,getMessage(msg));
executor.execute(service);
clientsAndThreads.put(client, service);
}catch(Exception e){
System.err.println("error occurred while accepting connections");
}
}
}
}).start();
System.out.println("now dequeuing");
while(true){
dequeue();
}
}catch(Exception e){
System.err.println("Server:error while accepting connections"+e.getMessage());
}
}
public static void enqueue(Socket clientSocket,Integer secondsToWait){
try{
Runnable respectiveThread = clientsAndThreads.get(clientSocket);
threadAndRespectiveTime.put(respectiveThread, secondsToWait);
System.out.println("making thread wait");
synchronized (respectiveThread) {
respectiveThread.wait();
}
requestQueue.add(respectiveThread);
System.out.println("done enqueuing");
}catch(Exception e){
e.printStackTrace();
}
}
public static void dequeue() throws InterruptedException{
while(!requestQueue.isEmpty()){
Runnable currentThread=requestQueue.get(0);
Integer timeToWait=threadAndRespectiveTime.get(currentThread);
Thread.sleep(timeToWait * 1000);
requestQueue.remove(0);
System.out.println("wait is complete now notifying thread");
synchronized (currentThread) {
currentThread.notify();
}
}
}
/*
* This method takes out actual message from http format
*/
public String getMessage(String str){
return str.substring(str.indexOf("message:")+8, str.length());
}
/*
* Starts the server listening to port 4000
*/
public void start_server(){
try{
if(server==null || !server.isBound()){
server = new ServerSocket(4000);
}
acceptConnection();
}catch(Exception e){
System.err.println("Server:error occurred while server start"+e.getMessage());
}
}
/*
* Closes client sockets of every connected client, shuts down the thread executor that serves clients
*/
public void stop_server() throws IOException{
Iterator it=clientsConnected.entrySet().iterator();
while(it.hasNext()){
Map.Entry e= (Map.Entry)it.next();
Socket toBeClosed=(Socket)e.getKey();
toBeClosed.close();
}
executor.shutdownNow();
server.close();
}
}
Below is the class which is spawn as thread by Server.java
ServerService.java
`import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.Socket;
import java.util.Date;
/*
* This class serves the client
*/
public class ServerService extends Server implements Runnable{
private Socket client=null;
private String clientBeingServed=null;
private DataOutputStream dout=null;
private DataInputStream din=null;
/*
* This is construcor that takes client sockte that already has been connected to server and client name.
* It initializes and input and output streams for serving the respective client
*/
public ServerService(Socket client,String name) throws IOException {
this.client=client;
this.clientBeingServed=name;
dout=new DataOutputStream(client.getOutputStream());
din=new DataInputStream(client.getInputStream());
}
/*
* takes out actual message sent by client from its http format
*/
public String getMessage(String str){
//System.out.println("returning\n"+str.substring(str.indexOf("message:")+8, str.length()));
return str.substring(str.indexOf("message:")+8, str.length());
}
/*
* This method converts a message string into HTTP formatted string
*/
public String getHttpMessage(String msg){
String str="POST Http/1.1 \n" + "Host: www.uta.com \n" + "User-Agent: Mozilla/5.0 \n"
+ "Content=type: application/x-www-form-urlencoded \n" + "Content-Length: " + msg.length() + " \n"
+ "Date:" + new Date() + " \n" + "message:" + msg;
return str;
}
/*
* This method execute when thread for this class is executed from Server.java file after connection is accepted
*/
@Override
public void run() {
int waitTime=0;
try{
while(client.isConnected()){
String msg=din.readUTF();
ServerWindow.write(msg);
waitTime=Integer.parseInt(getMessage(msg));
System.out.println("Equeing:"+clientBeingServed);
Server.enqueue(client, waitTime);
ServerWindow.write("Served client:"+clientBeingServed);
dout.writeUTF(getHttpMessage("Server waited "+waitTime+" seconds for "+clientBeingServed));
dout.flush();
}
client.close();
}catch(Exception e){
System.err.println("ServerService:error serving client"+clientBeingServed+e.getMessage());
}
}
}`
