[英]Promise.then not being invoked
继续我的问题 ,我创建了一个JavaScript类,该类使用一个远程url作为参数,然后将文件上传到S3(通过axios)。 这是课程:
const config = require('../config.json');
const stream = require('stream');
const axios = require('axios');
const AWS = require('aws-sdk');
class S3RemoteUploader {
constructor(remoteAddr){
this.remoteAddr = remoteAddr;
this.stream = stream;
this.axios = axios;
this.config = config;
this.AWS = AWS;
this.AWS.config.update({
accessKeyId: this.config.api_key,
secretAccessKey: this.config.api_secret
});
this.spacesEndpoint = new this.AWS.Endpoint(this.config.endpoint);
this.s3 = new this.AWS.S3({endpoint: this.spacesEndpoint});
this.file_name = this.remoteAddr.substring(this.remoteAddr.lastIndexOf('/')+1);
this.obj_key = this.config.subfolder+'/'+this.file_name;
this.content_type = 'application/octet-stream';
this.uploadStream();
}
uploadStream(){
const pass = new this.stream.PassThrough();
this.promise = this.s3.upload({
Bucket: this.config.bucket,
Key: this.obj_key,
ACL: this.config.acl,
Body: pass,
ContentType: this.content_type
}).promise();
return pass;
}
initiateAxiosCall() {
axios({
method: 'get',
url: this.remoteAddr,
responseType: 'stream'
}).then( (response) => {
if(response.status===200){
this.content_type = response.headers['content-type'];
response.data.pipe(this.uploadStream());
}
});
}
dispatch() {
this.initiateAxiosCall();
}
async finish(){
//console.log(this.promise); /* return Promise { Pending } */
return this.promise.then( (r) => {
console.log(r.Location);
return r.Location;
}).catch( (e)=>{
console.log(e);
});
}
run() {
this.dispatch();
this.finish();
}
}
如您所见,promise属性包含S3上传诺言。 然而, then
似乎并没有被以任何引用。 到目前为止,我已经尝试了以下方法:
testUpload = new S3RemoteUploader('https://avatars2.githubusercontent.com/u/41177');
testUpload.run();
//console.log(testUpload.promise); /* Returns Promise { Pending } */
testUpload.promise.then(r => console.log); // does nothing
我怀疑,承诺解决之前then
这里正在调用。
您的跑步应返回.then的承诺,以解决。 将您的代码更新为以下代码,并检查.then是否被调用。
finish(){
return this.promise;
}
run() {
this.dispatch();
return this.finish();
}
我已经修改了您的代码,请检查它是否适合您:
const config = require('../config.json');
const stream = require('stream');
const axios = require('axios');
const AWS = require('aws-sdk');
class S3RemoteUploader {
constructor(remoteAddr){
this.remoteAddr = remoteAddr;
this.stream = stream;
this.axios = axios;
this.config = config;
this.AWS = AWS;
this.AWS.config.update({
accessKeyId: this.config.api_key,
secretAccessKey: this.config.api_secret
});
this.spacesEndpoint = new this.AWS.Endpoint(this.config.endpoint);
this.s3 = new this.AWS.S3({endpoint: this.spacesEndpoint});
this.file_name = this.remoteAddr.substring(this.remoteAddr.lastIndexOf('/')+1);
this.obj_key = this.config.subfolder+'/'+this.file_name;
this.content_type = 'application/octet-stream';
this.uploadStream();
}
uploadStream(){
const pass = new this.stream.PassThrough();
this.promise = this.s3.upload({
Bucket: this.config.bucket,
Key: this.obj_key,
ACL: this.config.acl,
Body: pass,
ContentType: this.content_type
}).promise();
return pass;
}
initiateAxiosCall() {
return axios({
method: 'get',
url: this.remoteAddr,
responseType: 'stream'
});
}
dispatch() {
this.initiateAxiosCall().then( (response) => {
if(response.status===200){
this.content_type = response.headers['content-type'];
response.data.pipe(this.uploadStream());
this.finish();
}
});
}
async finish(){
//console.log(this.promise); /* return Promise { Pending } */
return this.promise.then( (r) => {
console.log(r.Location);
return r.Location;
}).catch( (e)=>{
console.log(e);
});
}
run() {
this.dispatch();
}
}
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