我正在学习websocket并且已经使用websocket / json完成了聊天程序.但我坚持上传ATM的文件.任何建议&回答会很感激.

服务器端：

package websocket;

import java.io.File;

import java.io.FileNotFoundException;

import java.io.FileOutputStream;

import java.io.IOException;

import java.nio.ByteBuffer;

import javax.websocket.CloseReason;

import javax.websocket.EndpointConfig;

import javax.websocket.OnClose;

import javax.websocket.OnError;

import javax.websocket.OnMessage;

import javax.websocket.OnOpen;

import javax.websocket.Session;

import javax.websocket.server.ServerEndpoint;

@ServerEndpoint("/receive/fileserver")

public class FileServer {

@OnOpen

public void open(Session session, EndpointConfig conf) {

System.out.println("chat ws server open");

}

@OnMessage

public void processUpload(ByteBuffer msg, boolean last, Session session) {

System.out.println("Binary message");

FileOutputStream fos = null;

File file = new File("D:/download/tmp.txt");

try {

fos = new FileOutputStream(file);

} catch (FileNotFoundException e) {

e.printStackTrace();

}

byte readdata = (byte) -999;

while(readdata!=-1) {

readdata=msg.get();

try {

fos.write(readdata);

} catch (IOException e) {

e.printStackTrace();

}

}

}

@OnMessage

public void message(Session session, String msg) {

System.out.println("got msg: " + msg + msg.length());

}

@OnClose

public void close(Session session, CloseReason reason) {

System.out.println("socket closed: "+ reason.getReasonPhrase());

}

@OnError

public void error(Session session, Throwable t) {

t.printStackTrace();

}

}

客户：

Chat

File Upload

Select file

var ws;

function connectChatServer() {

ws = new WebSocket(

"ws://localhost:8080/MyHomePage/receive/fileserver");

ws.binaryType = "arraybuffer";

ws.onopen = function() {

alert("Connected.")

};

ws.onmessage = function(evt) {

alert(evt.msg);

};

ws.onclose = function() {

alert("Connection is closed...");

};

ws.onerror = function(e) {

alert(e.msg);

}

}

function sendFile() {

var file = document.getElementById('filename').files[0];

var reader = new FileReader();

var rawData = new ArrayBuffer();

reader.loadend = function() {

}

reader.onload = function(e) {

rawData = e.target.result;

ws.send(rawData);

alert("the File has been transferred.")

}

reader.readAsBinaryString(file);

}

服务器端关闭原因消息如下

套接字关闭：解码的文本消息对于输出缓冲区而言太大,并且端点不支持部分消息

Q1：似乎是根据封闭原因找到文本处理方法而不是二进制处理方法,我该如何解决这个问题呢？

Q2：我应该将数据类型更改为Blob以在javascript端传输文件吗？那怎么样？

额外的问：可以有人链接websocket文件传输的示例源(java websocket或javascript或两者)？

谢谢阅读 ：)

解决方法:

经过一番研究和尝试,我发现’reader.readAsBinaryString(file);’是问题1的原因.将其更改为’reader.readAsArrayBuffer(file);’我的第一个问题已经解决了.

另外,由于websocket自动将文件作为多个部分数据传输,因此我更改了源代码如下.这有效！只有当文件大小不那么大时. ：/

更改了服务器端源：

package websocket;

import java.io.File;

import java.io.FileNotFoundException;

import java.io.FileOutputStream;

import java.io.IOException;

import java.nio.ByteBuffer;

import javax.websocket.CloseReason;

import javax.websocket.EndpointConfig;

import javax.websocket.OnClose;

import javax.websocket.OnError;

import javax.websocket.OnMessage;

import javax.websocket.OnOpen;

import javax.websocket.Session;

import javax.websocket.server.ServerEndpoint;

@ServerEndpoint("/receive/fileserver")

public class FileServer {

static File uploadedFile = null;

static String fileName = null;

static FileOutputStream fos = null;

final static String filePath="d:/download/";

@OnOpen

public void open(Session session, EndpointConfig conf) {

System.out.println("chat ws server open");

}

@OnMessage

public void processUpload(ByteBuffer msg, boolean last, Session session) {

System.out.println("Binary Data");

while(msg.hasRemaining()) {

try {

fos.write(msg.get());

} catch (IOException e) {

e.printStackTrace();

}

}

}

@OnMessage

public void message(Session session, String msg) {

System.out.println("got msg: " + msg);

if(!msg.equals("end")) {

fileName=msg.substring(msg.indexOf(':')+1);

uploadedFile = new File(filePath+fileName);

try {

fos = new FileOutputStream(uploadedFile);

} catch (FileNotFoundException e) {

e.printStackTrace();

}

}else {

try {

fos.flush();

fos.close();

} catch (IOException e) {

e.printStackTrace();

}

}

}

@OnClose

public void close(Session session, CloseReason reason) {

System.out.println("socket closed: "+ reason.getReasonPhrase());

}

@OnError

public void error(Session session, Throwable t) {

t.printStackTrace();

}

}

浏览器(客户端)方：

Chat

File Upload

Select file

var ws;

function connectChatServer() {

ws = new WebSocket(

"ws://localhost:8080/MyHomePage/receive/fileserver");

ws.binaryType = "arraybuffer";

ws.onopen = function() {

alert("Connected.")

};

ws.onmessage = function(evt) {

alert(evt.msg);

};

ws.onclose = function() {

alert("Connection is closed...");

};

ws.onerror = function(e) {

alert(e.msg);

}

}

function sendFile() {

var file = document.getElementById('filename').files[0];

ws.send('filename:'+file.name);

var reader = new FileReader();

var rawData = new ArrayBuffer();

//alert(file.name);

reader.loadend = function() {

}

reader.onload = function(e) {

rawData = e.target.result;

ws.send(rawData);

alert("the File has been transferred.")

ws.send('end');

}

reader.readAsArrayBuffer(file);

}

我仍然无法弄清楚如何传输更大尺寸的文件. (我怀疑自动超时和/或缓冲区大小).有什么建议吗？

标签：javascript,java,blob,websocket

来源： https://codeday.me/bug/20190930/1835352.html