我试图在下面的代码中让另一个线程等待，但是我当前的线程本身正在无限等待。 下面是两个Java类Server.java，它们生成ServerService.java的可运行实例。 当这样的“ ServerService.java”正在运行的实例调用Server.java.Server.java的入队方法时，应使此类被调用者线程等待。但是似乎我的Server.java线程本身无限地等待着
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();
}
}
下面是由Server.java作为线程生成的类
`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());
}
}
}`
答案 0 :(得分：0)
我的ServerService线程实例在调用Server.java的入队方法之后会自行等待，而不是在生成的线程上调用wait。 然后，稍后Server.java调用将通知以恢复ServerService线程。
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.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Queue;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.SynchronousQueue;
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 Queue<Thread> requestQueue=null;
public static Map<Thread,Integer> threadAndRespectiveTime=null;
/*
* Contructor
*/
Server(){
clientsConnected=new HashMap<Socket,String>();
clientsAndThreads=new HashMap<Socket,Runnable>();
threadAndRespectiveTime=new HashMap<>();
requestQueue=new LinkedList<>();
}
/*
* 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);
}catch(Exception e){
System.err.println("error occurred while accepting connections");
}
}
}
}).start();
new Thread(new Runnable() {
@Override
public void run() {
try {
while(true){
Server.dequeue();
}
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}).start();
}catch(Exception e){
System.err.println("Server:error while accepting connections"+e.getMessage());
}
}
public static synchronized void enqueue(Thread t,Integer secondsToWait){
try{
System.out.println(requestQueue );
threadAndRespectiveTime.put(t, secondsToWait);
requestQueue.add(t);
}catch(Exception e){
e.printStackTrace();
}
}
public static synchronized void dequeue() throws InterruptedException{
while(!requestQueue.isEmpty()){
Thread currentThread=requestQueue.remove();
Integer timeToWait=threadAndRespectiveTime.get(currentThread);
System.out.println("time to wait is:"+timeToWait);
Thread.currentThread().sleep(timeToWait * 1000);
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();
}
}
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(Thread.currentThread(), waitTime);
System.out.println("before going to sleep");
synchronized (Thread.currentThread()) {
Thread.currentThread().wait();
}
System.out.println("after sleeping");
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());
}
}
}