net.createserver上的Node js事件发射器

Question

所以我遇到了一个问题，并停留了大约3天，我使用node js作为套接字服务器来接收字符串，并处理一些json数据来向socket客户端提供字符串响应，在node js(net，events(中使用的堆栈，我的代码对第一个请求没有问题，但在第二个请求之后，它出现了这样的错误(服务器(：

[2020-12-23T07:45:13.821Z] server listening on port: 4444
[2020-12-23T07:45:15.696Z] New Connection : ::ffff:127.0.0.1
[2020-12-23T07:45:15.701Z] message: string
[2020-12-23T07:45:15.702Z] executing call function
[2020-12-23T07:45:15.703Z] oncall function
[2020-12-23T07:45:15.703Z] executing emit
[2020-12-23T07:45:15.704Z] {
orig: 'orig',
origParam: { number: '123456' },
resp: [
{
content: [Array],
firstPage: true,
lastPage: true,
number: 0,
numberOfElements: 1,
size: 1,
sort: null,
totalElements: 1
},
{ result: 'UNMATCHED' }
]
}
[2020-12-23T07:45:15.707Z] Returning : diterima
[2020-12-23T07:45:42.403Z] New Connection : ::ffff:127.0.0.1
[2020-12-23T07:45:42.407Z] message: string
[2020-12-23T07:45:42.408Z] executing call function
[2020-12-23T07:45:42.408Z] oncall function
[2020-12-23T07:45:42.409Z] executing emit
[2020-12-23T07:45:42.409Z] {
orig: 'orig',
origParam: { number: '123456' },
resp: [
{
content: [Array],
firstPage: true,
lastPage: true,
number: 0,
numberOfElements: 1,
size: 1,
sort: null,
totalElements: 1
},
{ result: 'UNMATCHED' }
]
}
[2020-12-23T07:45:42.410Z] Returning : diterima
[2020-12-23T07:45:42.411Z] {
orig: 'orig',
origParam: { number: '123456' },
resp: [
{
content: [Array],
firstPage: true,
lastPage: true,
number: 0,
numberOfElements: 1,
size: 1,
sort: null,
totalElements: 1
},
{ result: 'UNMATCHED' }
]
}
[2020-12-23T07:45:42.412Z] Returning : diterima
events.js:288
throw er; // Unhandled 'error' event
^
Error: This socket has been ended by the other party
at Socket.writeAfterFIN [as write] (net.js:451:14)
at HanaconsResponded.<anonymous> (C:Usersralfian------.js:47:11)
at HanaconsResponded.emit (events.js:323:22)
at callFunction (C:Usersralfian------.js:79:23)
at Socket.<anonymous> (C:Usersralfian------.js:35:17)
at Socket.emit (events.js:311:20)
at addChunk (_stream_readable.js:294:12)
at readableAddChunk (_stream_readable.js:271:13)
at Socket.Readable.push (_stream_readable.js:209:10)
at TCP.onStreamRead (internal/stream_base_commons.js:186:23)
Emitted 'error' event on Socket instance at:
at emitErrorNT (net.js:1336:8)
at processTicksAndRejections (internal/process/task_queues.js:84:21) {
code: 'EPIPE'
}

下面是客户端在第二次请求时的错误，(第一次请求没有问题(：

CLIENT: I connected to the server.
{"orig":"orig","origParam":{"number":"123456"},"resp":[{"content":[{"gender":"not match"}],"firstPage":true,"lastPage":true,"number":0,"numb
erOfElements":1,"size":1,"sort":null,"totalElements":1},{"result":"UNMATCHED"}]}
events.js:288
throw er; // Unhandled 'error' event
^
Error: read ECONNRESET
at TCP.onStreamRead (internal/stream_base_commons.js:205:27)
Emitted 'error' event on Socket instance at:
at emitErrorNT (internal/streams/destroy.js:92:8)
at emitErrorAndCloseNT (internal/streams/destroy.js:60:3)
at processTicksAndRejections (internal/process/task_queues.js:84:21) {
errno: 'ECONNRESET',
code: 'ECONNRESET',
syscall: 'read'
}

这是我的服务器代码：

var net = require('net');
var server = net.createServer();
require('log-timestamp');
var hostport = 4444;
var EventEmitter = require('events');
class CheckResponded extends EventEmitter {}
var checkResponded = new CheckResponded();
server.listen({
port : hostport,
exclusive: true
},);
console.log('server listening on ' + 'port: ' + hostport);
server.on('connection', (e) => {

console.log( 'New Connection : ' + e.remoteAddress );
e.setEncoding('utf8');
e.setTimeout(60000);
e.on('end', () => {})
e.on( 'timeout', () => {
console.log('Socket Timeout. Reseting.');
e.end();
});
e.on( 'data', (buff) => {
console.log("message: " + typeof buff);
try {
if (buff === "exec"){
console.log("executing call function")
callFunction()
}
} catch(error){
console.log('error on socket -> ' + error)
}
});
checkResponded.on( 'event1', (f) => {
console.log(f)
var rmsg;
rmsg = f;
console.log("Returning : " + 'diterima');
e.write(JSON.stringify(rmsg));
});
});
function callFunction() {
console.log('oncall function')
var imsg = {
"orig": "orig",
"origParam": {
"number": "123456",
},
"resp": [
{
"content": [
{
"gender": "not match",
}
],
"firstPage": true,
"lastPage": true,
"number": 0,
"numberOfElements": 1,
"size": 1,
"sort": null,
"totalElements": 1
},
{
"result": "UNMATCHED"
}
]
}
console.log('executing emit')
checkResponded.emit('event1', imsg);
return
}

下面是客户端请求示例：

const net = require('net');
var host = 'localhost';
const client = net.createConnection({ port: 4444, host: host }, () => {
console.log('CLIENT: I connected to the server.');
client.write('exec')
});
client.on('data', (data) => {
console.log(data.toString());
client.end();
});
client.on('end', () => {
console.log('CLIENT: I disconnected from the server.');
});

寻求帮助，谢谢！

Answer 1

我看到的一件事是，您的客户端代码假设您的整个响应在一个data事件中到达。这不是一个安全的假设。有时可能会发生这种情况，但这并不能保证，如果服务器在您调用client.end()时没有发送完数据，您将在服务器上收到一个错误(就像您一样(，例如：

Error: This socket has been ended by the other party

你需要在发送的数据中使用某种协议，这样你就可以解析传入的数据，然后你就可以知道什么时候有完整的响应，什么时候需要等待其余的数据到达。

这里讨论的类似问题：检测在'；数据'；Node.js 的Net模块中的事件