我正在开发一个在套接字服务器上构建群聊应用的项目！ 但是当我启动服务器时，它会启动并显示以下错误：
HTTP Status 404- /GroupChat/
type Status report
message /GroupChat/
description The requested resource is not available.
我正在使用J2EE eclipse，我添加了一个tomcat 7服务器。
以下是我的两个文件：
JSONUtils.java
package com.groupchat;
import org.json.JSONException;
import org.json.JSONObject;
public class JSONUtils {
// flags to identify the kind of json response on client side
private static final String FLAG_SELF = "self", FLAG_NEW = "new",
FLAG_MESSAGE = "message", FLAG_EXIT = "exit";
public JSONUtils() {
}
/**
* Json when client needs it's own session details
* */
public String getClientDetailsJson(String sessionId, String message) {
String json = null;
try {
JSONObject jObj = new JSONObject();
jObj.put("flag", FLAG_SELF);
jObj.put("sessionId", sessionId);
jObj.put("message", message);
json = jObj.toString();
} catch (JSONException e) {
e.printStackTrace();
}
return json;
}
/**
* Json to notify all the clients about new person joined
* */
public String getNewClientJson(String sessionId, String name,
String message, int onlineCount) {
String json = null;
try {
JSONObject jObj = new JSONObject();
jObj.put("flag", FLAG_NEW);
jObj.put("name", name);
jObj.put("sessionId", sessionId);
jObj.put("message", message);
jObj.put("onlineCount", onlineCount);
json = jObj.toString();
} catch (JSONException e) {
e.printStackTrace();
}
return json;
}
/**
* Json when the client exits the socket connection
* */
public String getClientExitJson(String sessionId, String name,
String message, int onlineCount) {
String json = null;
try {
JSONObject jObj = new JSONObject();
jObj.put("flag", FLAG_EXIT);
jObj.put("name", name);
jObj.put("sessionId", sessionId);
jObj.put("message", message);
jObj.put("onlineCount", onlineCount);
json = jObj.toString();
} catch (JSONException e) {
e.printStackTrace();
}
return json;
}
/**
* JSON when message needs to be sent to all the clients
* */
public String getSendAllMessageJson(String sessionId, String fromName,
String message) {
String json = null;
try {
JSONObject jObj = new JSONObject();
jObj.put("flag", FLAG_MESSAGE);
jObj.put("sessionId", sessionId);
jObj.put("name", fromName);
jObj.put("message", message);
json = jObj.toString();
} catch (JSONException e) {
e.printStackTrace();
}
return json;
}
}
SocketServer.java
@ServerEndpoint("/chat")
public class SocketServer {
// set to store all the live sessions
private static final Set<Session> sessions = Collections
.synchronizedSet(new HashSet<Session>());
// Mapping between session and person name
private static final HashMap<String, String> nameSessionPair = new HashMap<String, String>();
private JSONUtils jsonUtils = new JSONUtils();
// Getting query params
public static Map<String, String> getQueryMap(String query) {
Map<String, String> map = Maps.newHashMap();
if (query != null) {
String[] params = query.split("&");
for (String param : params) {
String[] nameval = param.split("=");
map.put(nameval[0], nameval[1]);
}
}
return map;
}
/**
* Called when a socket connection opened
* */
@OnOpen
public void onOpen(Session session) {
System.out.println(session.getId() + " has opened a connection");
Map<String, String> queryParams = getQueryMap(session.getQueryString());
String name = "";
if (queryParams.containsKey("name")) {
// Getting client name via query param
name = queryParams.get("name");
try {
name = URLDecoder.decode(name, "UTF-8");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
// Mapping client name and session id
nameSessionPair.put(session.getId(), name);
}
// Adding session to session list
sessions.add(session);
try {
// Sending session id to the client that just connected
session.getBasicRemote().sendText(
jsonUtils.getClientDetailsJson(session.getId(),
"Your session details"));
} catch (IOException e) {
e.printStackTrace();
}
// Notifying all the clients about new person joined
sendMessageToAll(session.getId(), name, " joined conversation!", true, false);
}
/**
* method called when new message received from any client
*
* @param message
* JSON message from client
* */
@OnMessage
public void onMessage(String message, Session session) {
System.out.println("Message from " + session.getId() + ": " + message);
String msg = null;
// Parsing the json and getting message
try {
JSONObject jObj = new JSONObject(message);
msg = jObj.getString("message");
} catch (JSONException e) {
e.printStackTrace();
}
// Sending the message to all clients
sendMessageToAll(session.getId(), nameSessionPair.get(session.getId()),
msg, false, false);
}
/**
* Method called when a connection is closed
* */
@OnClose
public void onClose(Session session) {
System.out.println("Session " + session.getId() + " has ended");
// Getting the client name that exited
String name = nameSessionPair.get(session.getId());
// removing the session from sessions list
sessions.remove(session);
// Notifying all the clients about person exit
sendMessageToAll(session.getId(), name, " left conversation!", false, true);
}
/**
* Method to send message to all clients
*
* @param sessionId
* @param message
* message to be sent to clients
* @param isNewClient
* flag to identify that message is about new person joined
* @param isExit
* flag to identify that a person left the conversation
* */
private void sendMessageToAll(String sessionId, String name,
String message, boolean isNewClient, boolean isExit) {
// Looping through all the sessions and sending the message individually
for (Session s : sessions) {
String json = null;
// Checking if the message is about new client joined
if (isNewClient) {
json = jsonUtils.getNewClientJson(sessionId, name, message,
sessions.size());
} else if (isExit) {
// Checking if the person left the conversation
json = jsonUtils.getClientExitJson(sessionId, name, message, sessions.size());
} else {
// Normal chat conversation message
json = jsonUtils
.getSendAllMessageJson(sessionId, name, message);
}
try {
System.out.println("Sending Message To: " + sessionId + ", " + json);
s.getBasicRemote().sendText(json);
} catch (IOException e) {
System.out.println("error in sending. " + s.getId() + ", "
+ e.getMessage());
e.printStackTrace();
}
}
}
}
main.js
@ServerEndpoint("/chat")
public class SocketServer {
// set to store all the live sessions
private static final Set<Session> sessions = Collections
.synchronizedSet(new HashSet<Session>());
// Mapping between session and person name
private static final HashMap<String, String> nameSessionPair = new HashMap<String, String>();
private JSONUtils jsonUtils = new JSONUtils();
// Getting query params
public static Map<String, String> getQueryMap(String query) {
Map<String, String> map = Maps.newHashMap();
if (query != null) {
String[] params = query.split("&");
for (String param : params) {
String[] nameval = param.split("=");
map.put(nameval[0], nameval[1]);
}
}
return map;
}
/**
* Called when a socket connection opened
* */
@OnOpen
public void onOpen(Session session) {
System.out.println(session.getId() + " has opened a connection");
Map<String, String> queryParams = getQueryMap(session.getQueryString());
String name = "";
if (queryParams.containsKey("name")) {
// Getting client name via query param
name = queryParams.get("name");
try {
name = URLDecoder.decode(name, "UTF-8");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
// Mapping client name and session id
nameSessionPair.put(session.getId(), name);
}
// Adding session to session list
sessions.add(session);
try {
// Sending session id to the client that just connected
session.getBasicRemote().sendText(
jsonUtils.getClientDetailsJson(session.getId(),
"Your session details"));
} catch (IOException e) {
e.printStackTrace();
}
// Notifying all the clients about new person joined
sendMessageToAll(session.getId(), name, " joined conversation!", true, false);
}
/**
* method called when new message received from any client
*
* @param message
* JSON message from client
* */
@OnMessage
public void onMessage(String message, Session session) {
System.out.println("Message from " + session.getId() + ": " + message);
String msg = null;
// Parsing the json and getting message
try {
JSONObject jObj = new JSONObject(message);
msg = jObj.getString("message");
} catch (JSONException e) {
e.printStackTrace();
}
// Sending the message to all clients
sendMessageToAll(session.getId(), nameSessionPair.get(session.getId()), msg, false, false);
}
/**
* Method called when a connection is closed
* */
@OnClose
public void onClose(Session session) {
System.out.println("Session " + session.getId() + " has ended");
// Getting the client name that exited
String name = nameSessionPair.get(session.getId());
// removing the session from sessions list
sessions.remove(session);
// Notifying all the clients about person exit
sendMessageToAll(session.getId(), name, " left conversation!", false, true);
}
/**
* Method to send message to all clients
*
* @param sessionId
* @param message
* message to be sent to clients
* @param isNewClient
* flag to identify that message is about new person joined
* @param isExit
* flag to identify that a person left the conversation
* */
private void sendMessageToAll(String sessionId, String name,
String message, boolean isNewClient, boolean isExit) {
// Looping through all the sessions and sending the message individually
for (Session s : sessions) {
String json = null;
// Checking if the message is about new client joined
if (isNewClient) {
json = jsonUtils.getNewClientJson(sessionId, name, message,
sessions.size());
} else if (isExit) {
// Checking if the person left the conversation
json = jsonUtils.getClientExitJson(sessionId, name, message, sessions.size());
} else {
// Normal chat conversation message
json = jsonUtils
.getSendAllMessageJson(sessionId, name, message);
}
try {
System.out.println("Sending Message To: " + sessionId + ", " + json);
s.getBasicRemote().sendText(json);
} catch (IOException e) {
System.out.println("error in sending. " + s.getId() + ", "
+ e.getMessage());
e.printStackTrace();
}
}
}
}
答案 0 :(得分：0)
首先，404代码表明该元素不存在，那么您的问题可能是注释@ServerEndpoint("/chat")，HTTP请求正在寻找/ GroupChat /元素。现在，您还必须检查您的设置文件（web.xml，context.xml，application.xml等），因为您可能具有错误配置的上下文属性或显示名称属性。
我希望这些信息可以帮到你。
祝你好运。