我想使用两个IBMWatson服务,将两者的响应组合在一个变量中,并将其作为回调返回。我不知道如何在http请求之外获得response1值,以便将其与其他IBMWatson服务的response2相结合。
我尝试了下面的代码,但没有成功。我读到我可以使用承诺,但我对此很陌生,不知道如何做到这一点。
有人能帮忙吗?
const AWS = require('aws-sdk');
var http = require('https');
exports.handler = (event, context, callback) => {
var text = JSON.stringify(event.text);
var options = {
method: process.env.method,
hostname: process.env.watson_hostname,
port: null,
path: process.env.path,
headers: {
'content-type': process.env.content_type,
authorization: process.env.authorization,
'cache-control': process.env.cache_control,
'X-Watson-Learning-Opt-Out': 'true'
}
};
var req = http.request(options, function (res) {
var chunks = "";
res.on("data", function (chunk) {
chunks+ = chunk.toString();;
});
res.on("end", function () {
var response1 = (chunks);
//////////////here I need to get reponse2
var response2 = IBM2();
var bothResponses = response1 + response2
callback(null,bothResponses)
});
})
req.write(text);
req.end()
function IBM2(){
var text = JSON.stringify(event.text);
var options = {
method: process.env.method2,
hostname: process.env.watson_hostname2,
port: null,
path: process.env.path2,
headers: {
'content-type': process.env.content_type2,
authorization: process.env.authorization2,
'cache-control': process.env.cache_control,
'X-Watson-Learning-Opt-Out': 'true'
}
};
var req = http.request(options, function (res) {
var chunks = [];
res.on("data", function (chunk) {
chunks.push(chunk);
});
res.on("end", function () {
var response2 = JSON.parse(Buffer.concat(chunks));
return(response2)
}
从IBM2
函数返回promise,并在调用函数中使用async await进行处理。请注意end回调中之前的async
关键字。
我已经尝试将Promise添加到您现有的流程中:
const AWS = require('aws-sdk');
var http = require('https');
exports.handler = (event, context, callback) => {
var text = JSON.stringify(event.text);
var options = {
method: process.env.method,
hostname: process.env.watson_hostname,
port: null,
path: process.env.path,
headers: {
'content-type': process.env.content_type,
authorization: process.env.authorization,
'cache-control': process.env.cache_control,
'X-Watson-Learning-Opt-Out': 'true'
}
};
var req = http.request(options, function (res) {
var chunks = "";
res.on("data", function (chunk) {
chunks += chunk.toString();;
});
res.on("end", async function () {
var response1 = (chunks);
//////////////here I need to get reponse2
var response2 = await IBM2();
// validate response2 (in case IBM2 throws error)
var bothResponses = response1 + response2;
callback(null,bothResponses)
});
});
req.write(text);
req.end();
function IBM2(){
return new Promise((resolve, reject) =>{
var text = JSON.stringify(event.text);
var options = {
method: process.env.method2,
hostname: process.env.watson_hostname2,
port: null,
path: process.env.path2,
headers: {
'content-type': process.env.content_type2,
authorization: process.env.authorization2,
'cache-control': process.env.cache_control,
'X-Watson-Learning-Opt-Out': 'true'
}
};
var req = http.request(options, function (res) {
var chunks = [];
res.on("data", function (chunk) {
chunks.push(chunk);
});
res.on("end", function () {
var response2 = JSON.parse(Buffer.concat(chunks));
resolve(response2)
});
res.on("error", function (err) {
reject(err);
});
})
});
}
};
在对代码进行任何更改之前,我建议您先了解这些主题。作为参考,请查看promise和异步等待的概念
Promiese
异步/等待
不知道你是否有其他错误,但看起来你没有等待response2完成,可能是之类的错误
const response2 = await IBM2():
或者,如果你想使用承诺,也许可以像这样:
res.on('end', function () {
var response2 = IBM2().then(
val => {
var bothResponses = response1 + val;
callback(null, bothResponses);
},
reject => {
/* handle rejection here */
},
);
});