node.js 应用程序需要使用 Promise 来确保在运行后续命令之前返回一个函数的结果。但是，下面的代码在 getUser(theToken) promise 函数应该返回其值的地方卡住。 为了使 getUser(theToken) promise 函数能够返回它在内部生成的有效值，需要对下面的代码进行哪些具体更改？
app.get('/auth/provider/callback', function(req, res) {
var queryData = url.parse(req.url, true).query;
//This is the end of Step C in the flow
// code was in the GET request, ex: http://localhost:8080/login?code=w6zGJO&state=IuaO63
console.log('Finished Step C of Authorization Code Flow. Welcome back from authserver');
console.log('queryData.code is: ' + queryData.code);
//Now start Step D in the flow
console.log('About to start Step D of Authorization Code Flow. ');
var tokenUrl = oAuthConfig.tokenUrl + '?grant_type=' + oAuthConfig.grantType + '&code='+queryData.code+'&client_id=' + oAuthConfig.clientID + '&redirect_uri=' + oAuthConfig.callbackUrl;
request.post(tokenUrl, function(err, response, body){
if(err){console.log('ERROR with token request.')}
// Step E is the response received as follows:
var data = JSON.parse(body);
console.log('JSON data response is: ' + data);
getUser(data.access_token).then(function(message) {
console.log('in callback, jwtJSON is: ');console.log(message);
res.redirect(somewhere);
});
});
console.log('The POST is finished. Waiting for response.');
console.log('Step D. Token Request Sent To AuthServer.');
});
然后在同一文件中下面的 getUser(theToken) 函数是:
function getUser(theToken) {//returns JWT
return new Promise(function(resolve, reject) {
console.log('in getUser, theToken is: ');console.log(theToken);
var jwtJSON = { "token" : "anonymous" };
request({
method: 'GET', url: authServer + '/uaa/user', json: true,
auth: { user: null, password: null, sendImmediately: true, bearer: theToken }
}, function (error, response, body) {
if(error){
console.log('in getUser, ERROR with user request.');console.log(error);
jwtJSON = { "token" : "error" };
return jwtJSON;//
}
else {
var uname = '';var jwtUser = 'empty';
console.log('in getUser, response.statusCode is: ');console.log(response.statusCode);
if(body['name'] && body['name'].length > 0 ){
uname = body['name'];console.log('uname is: ');console.log(uname);
client.exists(uname, function(err, reply) {//Check to see if a Redis key for the user already exists
if (reply === 1) {//a redis key DOES exist
console.log('\"'+uname+'\" exists');
client.expire(uname, 10);//set the key to expire in 10 seconds. use this to manage session length
client.hgetall(uname, function(err, object) {
if(object && object["jwt"]) {
jwtJSON = { "token" : object["jwt"] };
console.log('in getUser, jwtJSON is: ');console.log(jwtJSON);
return jwtJSON;
} else { return jwtJSON; }
});
} else {//a redis key DOES NOT exist
console.log('\"'+uname+'\" doesn\'t exist');
jwtUser = generateJwt(uname, authoritiesLocal);
client.hmset(uname, {//store a hash/object
'jwt' : jwtUser
});
jwtJSON = { "token" : jwtUser };console.log('in getUser, jwtJSON is: ');console.log(jwtJSON);
client.expire(uname, 10);//set the key to expire in 10 seconds. use this to manage session length
return jwtJSON;
}
});//end of Redis conditional block
console.log('jwtJSON is: ');console.log(jwtJSON);
} else { return jwtJSON; }
};
});
});
};
控制台打印输出为:
Finished Step C of Authorization Code Flow. Welcome back from authserver
queryData.code is: 0oxzu6
About to start Step D of Authorization Code Flow.
The POST is finished. Waiting for response.
Step D. Token Request Sent To AuthServer.
JSON data response is: [object Object]
in getUser, theToken is:
eyJ_SomeLongToken_hbG
in getUser, response.statusCode is:
200
uname is:
user
jwtJSON is:
{ token: 'anonymous' }
"user" doesn't exist
in getUser, jwtJSON is:
{ token: 'eyJ_TheSameLongToken_hbG' }
然后程序执行暂停几秒钟，然后第二次运行该序列，第二次产生错误，因为第二次没有填充任何变量。
最佳答案
您需要使用resolve 和reject 参数而不是返回值。我已将您的返回语句替换为 resolve 和 reject。然后你传入在 then
function getUser(theToken) { //returns JWT
return new Promise(function(resolve, reject) {
console.log('in getUser, theToken is: ');
console.log(theToken);
var jwtJSON = {
"token": "anonymous"
};
request({
method: 'GET',
url: authServer + '/uaa/user',
json: true,
auth: {
user: null,
password: null,
sendImmediately: true,
bearer: theToken
}
}, function(error, response, body) {
if (error) {
console.log('in getUser, ERROR with user request.');
console.log(error);
jwtJSON = {
"token": "error"
};
/* REJECT INSTEAD OF RETURN */
reject(jwtJSON);
} else {
var uname = '';
var jwtUser = 'empty';
console.log('in getUser, response.statusCode is: ');
console.log(response.statusCode);
if (body.name && body.name.length > 0) {
uname = body.name;
console.log('uname is: ');
console.log(uname);
client.exists(uname, function(err, reply) { //Check to see if a Redis key for the user already exists
if (reply === 1) { //a redis key DOES exist
console.log('\"' + uname + '\" exists');
client.expire(uname, 10); //set the key to expire in 10 seconds. use this to manage session length
client.hgetall(uname, function(err, object) {
if (object && object.jwt) {
jwtJSON = {
"token": object.jwt
};
console.log('in getUser, jwtJSON is: ');
console.log(jwtJSON);
/* RESOLVE INSTEAD OF RETURN */
resolve(jwtJSON);
} else {
/* RESOLVE INSTEAD OF RETURN */
resolve(jwtJSON);
}
});
} else { //a redis key DOES NOT exist
console.log('\"' + uname + '\" doesn\'t exist');
jwtUser = generateJwt(uname, authoritiesLocal);
client.hmset(uname, { //store a hash/object
'jwt': jwtUser
});
jwtJSON = {
"token": jwtUser
};
console.log('in getUser, jwtJSON is: ');
console.log(jwtJSON);
client.expire(uname, 10); //set the key to expire in 10 seconds. use this to manage session length
/* RESOLVE INSTEAD OF RETURN */
resolve(jwtJSON);
}
}); //end of Redis conditional block
console.log('jwtJSON is: ');
console.log(jwtJSON);
} else {
/* RESOLVE INSTEAD OF RETURN */
resolve(jwtJSON);
}
}
});
});
}
关于javascript - Node.js Promise 函数在返回前卡住执行，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/38490693/