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我正在尝试使用 java websocket api 在两个 html 页面之间实现简单的视频传输。网络摄像头服务器捕获网络摄像头并将其发送到服务器端点，该端点向每个连接的客户端广播。网络摄像头服务器代码

<video autoplay id="vid" style="display: none;"></video>
    <canvas id="canvas" width="640" height="480" style="border: 1px solid #d3d3d3;"></canvas>
    <div id="data1"></div>
    <script>
           var video = document.querySelector("#vid");
           var canvas = document.querySelector('#canvas');
           var ctx = canvas.getContext('2d');
           var localMediaStream = null;
           var ws = new WebSocket("ws://127.0.0.1:8080/WebApplication5/endpointwcv");
           ws.onopen = function () {
                console.log("Openened connection to websocket");
            };
            ws.onerror = function (evt) {
                writeToScreen('<span style="color: red;">ERROR:</span> ' + evt.data);
            };
           var onCameraFail = function (e) {
                console.log('Camera did not work.', e);
            };
            timer = setInterval(function () {
                              ctx.drawImage(video, 0, 0, 640, 480);
                              var data = canvas.toDataURL('image/jpeg', 1.0);
                              ws.send(data);
                              }, 255);

           navigator.getUserMedia = navigator.getUserMedia || navigator.webkitGetUserMedia || navigator.mozGetUserMedia || navigator.msGetUserMedia;
           window.URL = window.URL || window.webkitURL;
           navigator.getUserMedia({ video: true }, function (stream) {
                video.src = window.URL.createObjectURL(stream);

}, onCameraFail);

服务器端点的代码 /* 在此处导入 */

@ServerEndpoint("/endpointwcv")
public class NewWSEndpoint {
private static Set<Session> peers = Collections.synchronizedSet(new HashSet<Session>());

@OnMessage
public String onMessage( Session session,byte[] data) {
try {
        System.out.println(data);
    for(Session s:peers){

                    s.getBasicRemote().sendObject(data);
            }
} catch (IOException | EncodeException e) {
    System.out.println("Error in facedetection, ignoring message:" + e.getMessage());
}
    return null;
}

public String onMessage( Session session,String data) {
try {
        System.out.println(data);
    for(Session s:peers){

                    s.getBasicRemote().sendText(data);
            }
} catch (IOException e) {
    System.out.println("Error in facedetection, ignoring message:" + e.getMessage());
}
    return null;
}

@OnOpen
public void onOpen(Session session) throws IOException {
    peers.add(session);
    session.getBasicRemote().sendText("hiiiiiii");
}

@OnClose
public void onClose() {

    System.out.println("Closed");
}

@OnError
public void onError(Session s, Throwable t) {
    System.out.println("error");
}    
}

并且有一个访问网络摄像头的接收客户端

<div id="d1"></div>
    <canvas id="target" width="640" height="480" style="border: 1px solid #d3d3d3;"></canvas>
    <script>
        var ws = new WebSocket("ws://127.0.0.1:8080/WebApplication5/endpointwcv");
        var myURL = window.URL || window.webkitURL;
        ws.onopen = function () {
              console.log("Openened connection to websocket");
        };

        ws.onmessage=function (msg) {
                var target = document.getElementById("target");
                url=myURL.createObjectURL(msg);
                target.src = url;
        };
    </script>

在使用 java ee 7 api 在 GlassFish 4.0 上运行项目时，没有任何反应。请帮帮我。在控制台上有一个警告

WARNING:   Class 'javax.ejb.PostActivate' not found, interception based on it is not     enabled
WARNING:   Class 'javax.ejb.PrePassivate' not found, interception based on it is not     enabled

......

Exception starting filter WebSocket filter
java.lang.InstantiationException
at org.apache.catalina.core.ApplicationFilterConfig.(ApplicationFilterConfig.java:135)
at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:5297)
...

这是下载项目的链接

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1 回答 1

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我在这里看到您的项目存在一些问题。首先，您在 Struts 和 WebSocket 之间有一个 URL 映射重叠。您的 WebSocket URL 是/endpointwcv. 您的 Struts 映射是/*. 当我最终部署您的应用程序时，我收到了来自 Struts 的错误，提示我如何没有为 action 映射/endpointwcv。

如果您将 Struts 过滤器 servlet 的映射更改为/struts/*（我不得不更改filter-class为org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter以避免有关如何FilterDispatcher弃用的错误消息），您可以通过访问http://localhost:8080/WebApplication5/Conference.html. 在 GlassFish4 server.log 中，我看到了以下输出NewWSEndpoint：

INFO: aaaa
INFO: error
INFO: error
INFO: error
...
INFO: Closed

去http://localhost:8080/WebApplication5/ConferenceClient.html，我在 server.log 中看到：

INFO: aaaa

我不是 Struts 专家，但看起来您需要修复端点，然后弄清楚如何实现 Struts 前端，这样它就不会干扰您的 WebSocket 端点 URL。

于 2013-07-11T18:01:30.347 回答