应用环境:

B/S架构

需求描述:

1、判断U盘接入

2、扫描U盘指定文件,将满足条件的文件发送给服务器

解决思路:

1、因为bs架构,无法获取本机资源,计划在U盘所在服务器部署websocket服务

2、websocket服务扫描u盘,拿到指定文件,使用session.getBasicRemote().sendBinary(data)分批发送二进制流到客户端

3、web端的收到二进制流后将分批数据存到数组

4、数据接收全部完毕后,通过formData将数据提交到服务端进行保存,

5、当时想到websocket直接将文件传给后端服务器,但只想websocket服务只是作与web端的数据传输,具体文件还是由web端与后端服务器进行交互。

定时任务,检查U盘插入找到指定文件,并将文件的二进制流发给客户端

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import com.sims.tools.webSocket.WebSocketServer;
import org.springframework.scheduling.annotation.EnableScheduling;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Component;

import java.io.IOException;
import java.nio.file.FileSystems;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.List;

@EnableScheduling//开启定时任务
@Component
public class CheckTask {

    private static boolean findFile = false;

    private static boolean hasUsb = false;
    private static String usbPath = "";

    private static List<String> roots = new ArrayList<>();

    @Scheduled(cron = "0/5 * * * * ? ")
    public void cron()  {

        try {
            System.out.println("定时任务是否执行:" + !findFile+"--根目录文件夹数"+roots.size());
            if(findFile){
                //文件已经导入了
                System.out.println("文件已经导入了,如果想再导入,拨掉u盘再插入");
                List<String> newRoots = new ArrayList<>();
                FileSystems.getDefault().getRootDirectories().forEach(root -> {
                    newRoots.add(root.toString());
                });
                if(newRoots.size()<roots.size()){
                    //新目录少于现有目录,更新
                    findFile = false;
                    roots = newRoots;
                    usbPath = "";
                    System.out.println("U盘被拔出");
                }
            } else {
                //文件未导入,继续检测
                System.out.println("文件未导入,继续检测");
                if (roots.size() == 0) {
                    // 获取系统中的所有文件系统
                    FileSystems.getDefault().getRootDirectories().forEach(root -> {
                        roots.add(root.toString());
                    });
                } else {
                    List<String> newRoots = new ArrayList<>();
                    // 获取系统中的所有文件系统
                    FileSystems.getDefault().getRootDirectories().forEach(root -> {

                        if ((roots.indexOf(root.toString()) < 0) || (root.toString().equals(usbPath))) {
                            System.out.println("U盘已插入,路径为:" + root);
                            hasUsb = true;
                            usbPath = root.toString();
                            try {
                                Files.walk(root).forEach(path -> {
                                    if (Files.isRegularFile(path)) {
                                        if (path.toString().endsWith("erc")) {
                                            System.out.println("文件:" + path);
                                            JSONObject obj1 = new JSONObject();
                                            obj1.put("msgType","sendFileBegin");
                                            WebSocketServer.sendInfo(JSON.toJSONString(obj1), "user0");

                                            WebSocketServer.sendFile(path.toString(),"user0");

                                            JSONObject obj2 = new JSONObject();
                                            obj2.put("msgType","sendFileEnd");
                                            obj2.put("fileName",path.toString());
                                            WebSocketServer.sendInfo(JSON.toJSONString(obj2), "user0");
                                            findFile = true;
                                        }
                                    }
                                });
                            } catch (IOException e) {
                                System.out.println("io错误:" + e.getMessage());
                                findFile = false;
                            }
                        }
                        newRoots.add(root.toString());

                    });
                    if(newRoots.size()< roots.size()){
                        //U盘被拔出
                        System.out.println("U盘被拔出");
                        usbPath = "";
                        findFile = false;
                    }
                    roots = newRoots;

                }
            }
        } catch (Exception e) {
            System.out.println("报错了" + e.getMessage());
            findFile = false;
        }


    }

}

Websocket服务代码

import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Component;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import javax.websocket.*;
import javax.websocket.server.PathParam;
import javax.websocket.server.ServerEndpoint;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.net.InetAddress;
import java.net.NetworkInterface;
import java.net.SocketException;
import java.net.UnknownHostException;
import java.nio.ByteBuffer;
import java.util.concurrent.ConcurrentHashMap;

/**
 * websocket的处理类。
 * 作用相当于HTTP请求
 * 中的controller
 */
@Component
@Slf4j
@ServerEndpoint("/websocket/{userId}")
public class WebSocketServer {

    /**静态变量,用来记录当前在线连接数。应该把它设计成线程安全的。*/
    private static int onlineCount = 0;
    /**concurrent包的线程安全Set,用来存放每个客户端对应的WebSocket对象。*/
    private static ConcurrentHashMap<String,WebSocketServer> webSocketMap = new ConcurrentHashMap<>();
    /**与某个客户端的连接会话,需要通过它来给客户端发送数据*/
    private Session session;
    /**接收userId*/
    private String userId = "";

    public String getUserId(){
        return this.userId;
    }

    /**
     * 连接建立成
     * 功调用的方法
     */
    @OnOpen
    public void onOpen(Session session,@PathParam("userId") String userId) {
        this.session = session;
        this.userId=userId;
        if(webSocketMap.containsKey(userId)){
            webSocketMap.remove(userId);
            //加入set中
            webSocketMap.put(userId,this);
        }else{
            //加入set中
            webSocketMap.put(userId,this);
            //在线数加1
            addOnlineCount();
        }
        System.out.println("用户连接:"+userId+",当前在线人数为:" + getOnlineCount());
        try {
            InetAddress ip = InetAddress.getLocalHost();
            System.out.println("Current IP address : " + ip.getHostAddress());

            NetworkInterface network = NetworkInterface.getByInetAddress(ip);
            byte[] mac = network.getHardwareAddress();

            System.out.print("Current MAC address : ");

            StringBuilder sb = new StringBuilder();
            for (int i = 0; i < mac.length; i++) {
                sb.append(String.format("%02X%s", mac[i], (i < mac.length - 1) ? "-" : ""));
            }
            System.out.println(sb);
            JSONObject object = new JSONObject();
            object.put("ip",ip.getHostAddress());
            object.put("mac",sb);

            JSONObject obj = new JSONObject();
            obj.put("msgType","ipAndMac");
            obj.put("result",object);

            sendInfo(JSON.toJSONString(obj),this.userId);

        } catch (UnknownHostException e) {
            e.printStackTrace();
        } catch (SocketException e){
            e.printStackTrace();
        }
    }

    /**
     * 连接关闭
     * 调用的方法
     */
    @OnClose
    public void onClose() {
        if(webSocketMap.containsKey(userId)){
            webSocketMap.remove(userId);
            //从set中删除
            subOnlineCount();
        }
        System.out.println("用户退出:"+userId+",当前在线人数为:" + getOnlineCount());
    }

    /**
     * 收到客户端消
     * 息后调用的方法
     * @param message
     * 客户端发送过来的消息
     **/
    @OnMessage
    public void onMessage(String message, Session session) {
        System.out.println("用户消息:"+userId+",报文:"+message);
        //可以群发消息
        //消息保存到数据库、redis
        if(message!=null && message.length()>0){
            try {
                //解析发送的报文
                JSONObject jsonObject = JSON.parseObject(message);
                //追加发送人(防止串改)
                jsonObject.put("fromUserId",this.userId);
                String toUserId=jsonObject.getString("toUserId");
                //传送给对应toUserId用户的websocket
                if(toUserId!=null && toUserId.length()>0 &&webSocketMap.containsKey(toUserId)){
                    webSocketMap.get(toUserId).sendMessage(message);
                }else{
                    //否则不在这个服务器上,发送到mysql或者redis
                    System.out.println("请求的userId:"+toUserId+"不在该服务器上");
                }
            }catch (Exception e){
                e.printStackTrace();
            }
        }
    }


    /**
     * @param session
     * @param error
     */
    @OnError
    public void onError(Session session, Throwable error) {

        System.out.println("用户错误:"+this.userId+",原因:"+error.getMessage());
        error.printStackTrace();
    }

    /**
     * 实现服务
     * 器主动推送
     */
    public void sendMessage(String message) {
        try {
            this.session.getBasicRemote().sendText(message);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public void sendByteBuffer(ByteBuffer data) {
        System.out.print(data);
        try {
            session.getBasicRemote().sendBinary(data);

        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    /**
     *发送自定
     *义消息
     **/
    public static void sendInfo(String message, String userId) {
        System.out.println("发送消息到:"+userId+",报文:"+message);
        if(userId!=null && userId.length()>0 && webSocketMap.containsKey(userId)){
            webSocketMap.get(userId).sendMessage(message);
        }else{
            System.out.println("用户"+userId+",不在线!");
        }
    }

    public static void sendFile(String  path, String userId) {

        if(userId!=null && userId.length()>0 && webSocketMap.containsKey(userId)){
            try {
                File file = new File(path);
                FileInputStream fis = new FileInputStream(file);
                byte[] buffer = new byte[1024];
                int bytesRead;
                while ((bytesRead = fis.read(buffer)) != -1) {
                    ByteBuffer byteBuffer = ByteBuffer.wrap(buffer, 0, bytesRead);
                    webSocketMap.get(userId).sendByteBuffer(byteBuffer);
                }
                fis.close();
            } catch (Exception e) {
                e.printStackTrace();
            }

        }else{
            System.out.println("用户"+userId+",不在线!");
        }
    }

    /**
     *发送自定
     *义消息
     **/
    public void sendInfoToAll(String message) {
        System.out.println("发送报文:"+message);
        sendMessage(message);
    }

    /**
     * 获得此时的
     * 在线人数
     * @return
     */
    public static synchronized int getOnlineCount() {
        return onlineCount;
    }

    /**
     * 在线人
     * 数加1
     */
    public static synchronized void addOnlineCount() {
        WebSocketServer.onlineCount++;
    }

    /**
     * 在线人
     * 数减1
     */
    public static synchronized void subOnlineCount() {
        WebSocketServer.onlineCount--;
    }

}

Vue前端代码

websocketOnmessage: function (e){

      let data = e.data
      let that = this;
      console.log("rec====", data);
      if (this.isBlob(data)) {
        console.log("recdata===", data)
        this.recData.push(data);
      } else {
        let record = JSON.parse(data)
        if (record.msgType == "ipAndMac") {
          if(!sessionStorage.getItem('ipAndMac')){
            let result = record.result;
            loginLog(result).then(res=>{
              console.log('res',res)
              if(res.data.success){
                sessionStorage.setItem('ipAndMac',result)
              }          
            })
          }
        } else if (record.msgType == "sendFileBegin")  {
          //开始接收服务端发送过来的文件数据
          this.recData = [];
        } else if (record.msgType == "sendFileEnd") {
          //文件数据的接收完毕,合并数据并上传到业务服务器
          if (this.recData.length == 0) return;

          this.$showMsgBox({
            caption:"询问",
            msg: '检查到待导入文件' + record.fileName + ',是否导入?',
            callback:(data) => {
              if (data == "yes") {
                var formData = new FormData()
                formData.append('file', new Blob(this.recData))
                formData.append('fileName', record.fileName);      
                let url = config.configData.api_url  + "/business/biz/importAllByPath";
                utils.httpFile(url,formData).then((res) => {
                    if (res.data.success == true) {   
                        that.$showImport({tableData:res.data.data})
                    } else {
                        this.$showToast({msg: res.data.message});
                        return;    
                    }
                })
              }
            }
          })
        }
      }
      
    },

特别注意这个写法不要搞错,formData.append('file', new Blob(this.recData)),否则后端接受不到正确的格式数据。

服务端接收前端上传数据代码

@RequestMapping(value = "/importAllByPath", method = RequestMethod.POST)
    public Result<?> importAllByPath(HttpServletRequest request, HttpServletResponse response) {

        String fileName = request.getParameter("fileName");
        MultipartHttpServletRequest multipartRequest = (MultipartHttpServletRequest) request;
        Map<String, MultipartFile> fileMap = multipartRequest.getFileMap();
        for (Map.Entry<String, MultipartFile> entity : fileMap.entrySet()) {
            MultipartFile file = entity.getValue();// 获取上传文件对象
            try {

                String uuid = StrUtils.getTimeNo("sims_data_");
                String path = uploadpath + File.separator + "temp" + File.separator + uuid + File.separator;
                File dir = new File(path);
                if (!dir.exists()) {
                    dir.mkdirs();
                }
                String sFile = new File(path).getAbsolutePath() + File.separator + uuid + ".erc";

                try (FileOutputStream outputStream = new FileOutputStream(sFile)) {
                    byte[] bytes = file.getBytes();
                    outputStream.write(bytes);
                } catch (Exception e) {
                    return Result.error("文件导入失败:" + e.getMessage());
                }

                return Result.ok(result);


            } catch (Exception e) {
                return Result.error("文件导入失败:" + e.getMessage());
            }
        }
        return Result.ok("导入失败");

    }