Question

我正在尝试为get请求之一设置标头。以下是功能：

 getLeads(jwtToken: string): Observable<any>{
    const headers = new HttpHeaders();
    const authroizationToken = 'bearer '.concat(jwtToken);
    console.log(authroizationToken);          ------------------>  prints the token
    headers.append('Authorization', authroizationToken);
    console.log(headers.get('Authorization'));  ---------------------> this prints null
    var result = this.http.get<Leads>(this.getLeadsUrl, {headers});
    return result;
  }

但是heades.get（'Authorization'）出于某些原因为空，我无法弄清原因。任何帮助将不胜感激。

Answer 1

实际上.append返回新的标头对象。试试这个，它按预期工作。只需确保每次添加新的标头后都将标头分配回该变量即可。

   getLeads(jwtToken: string) {
    let headers = new HttpHeaders();
    const authroizationToken = 'bearer '.concat(jwtToken);
    console.log(authroizationToken);
    headers = headers.append('Authorization', authroizationToken);
    console.log(headers.get('Authorization'));
  }

这是工作中的Stackblitz

希望这会有所帮助：）

Answer 2

对代码进行以下更改：

SELECT
  SUM(
    CASE WHEN ISNULL(p.promo_code)
    AND h.account_number = c2.account_number THEN 1 ELSE 0 END
  ) as 'no_match_acct_match',
  SUM(
    CASE WHEN ISNULL(p.promo_code)
    AND (
      h.account_number <> c2.account_number
      OR ISNULL(c2.account_number)
    ) THEN 1 ELSE 0 END
  ) as 'no_match',
  SUM(
    CASE WHEN p.promo_code IS NOT NULL
    AND c.full_name = CONCAT(h.firstname, ' ', h.lastname)
    AND p.start_date > @today THEN 1 ELSE 0 END
  ) as 'future_name',
  SUM(
    CASE WHEN p.promo_code IS NOT NULL
    AND c.full_name = CONCAT(h.firstname, ' ', h.lastname)
    AND p.start_date <= @today
    AND p.`status` = 'REDEEMED' THEN 1 ELSE 0 END
  ) as 'redeemed_name',
  SUM(
    CASE WHEN p.promo_code IS NOT NULL
    AND c.full_name = CONCAT(h.firstname, ' ', h.lastname)
    AND p.start_date <= @today
    AND p.`status` <> 'REDEEMED'
    AND p.end_date < @today
    AND p.end_date + 259200 >= @today THEN 1 ELSE 0 END
  ) as 'buffered_name',
  SUM(
    CASE WHEN p.promo_code IS NOT NULL
    AND c.full_name = CONCAT(h.firstname, ' ', h.lastname)
    AND p.start_date <= @today
    AND p.`status` <> 'REDEEMED'
    AND p.end_date < @today
    AND p.end_date + 259200 < @today THEN 1 ELSE 0 END
  ) as 'expired_name',
  SUM(
    CASE WHEN p.promo_code IS NOT NULL
    AND c.full_name = CONCAT(h.firstname, ' ', h.lastname)
    AND p.start_date <= @today
    AND p.`status` <> 'REDEEMED'
    AND p.end_date >= @today THEN 1 ELSE 0 END
  ) as 'current_name',
  SUM(
    CASE WHEN p.promo_code IS NOT NULL
    AND c.full_name <> CONCAT(h.firstname, ' ', h.lastname)
    AND p.start_date > @today
    AND (
      r.resolve_status = 0
      OR ISNULL(r.resolve_status)
    ) THEN 1 ELSE 0 END
  ) as 'future_noname',
  SUM(
    CASE WHEN p.promo_code IS NOT NULL
    AND c.full_name <> CONCAT(h.firstname, ' ', h.lastname)
    AND p.start_date <= @today
    AND p.`status` = 'REDEEMED' THEN 1 ELSE 0 END
  ) as 'redeemed_noname',
  SUM(
    CASE WHEN p.promo_code IS NOT NULL
    AND c.full_name <> CONCAT(h.firstname, ' ', h.lastname)
    AND p.start_date <= @today
    AND p.`status` <> 'REDEEMED'
    AND p.end_date < @today
    AND p.end_date + 259200 >= @today THEN 1 ELSE 0 END
  ) as 'buffered_noname',
  SUM(
    CASE WHEN p.promo_code IS NOT NULL
    AND c.full_name <> CONCAT(h.firstname, ' ', h.lastname)
    AND p.start_date <= @today
    AND p.`status` <> 'REDEEMED'
    AND p.end_date < @today
    AND p.end_date + 259200 < @today THEN 1 ELSE 0 END
  ) as 'expired_noname',
  SUM(
    CASE WHEN p.promo_code IS NOT NULL
    AND c.full_name <> CONCAT(h.firstname, ' ', h.lastname)
    AND p.start_date <= @today
    AND p.`status` <> 'REDEEMED'
    AND p.end_date >= @today THEN 1 ELSE 0 END
  ) as 'current_noname'
FROM
  helpdesk h FORCE INDEX (help_status)
  LEFT JOIN promo_codes p ON h.promo_code = p.promo_code
  LEFT JOIN customer_promocode cp ON p.promo_code = cp.promo_code
  LEFT JOIN customers c ON cp.customer_number = c.customer_number
  LEFT JOIN customers c2 ON h.account_number = c2.account_number
  LEFT OUTER JOIN redeem_queue r ON p.promo_code = r.promo_code
WHERE
  h.help_status = 0
  AND h.in_view_by = ''
  AND (
    p.start_date >= UNIX_TIMESTAMP(SUBDATE(CURDATE(), INTERVAL 1 YEAR))
    OR p.start_date IS NULL
  )
  AND (
    ISNULL(p.promo_code)
    OR ISNULL(r.promo_code)
  )
group by
  p.promo_code,
  submitid

Answer 3

您可以使用HttpHeaders的set()方法：

在原始实例的克隆中设置或修改给定标头的值。如果标题已经存在，则将其值替换为返回对象中的给定值。

一个例子：

let header = new HttpHeaders().set(
  "Authorization",`bearer ${jwtToken}`
);

return this.http.get<Leads>(this.getLeadsUrl,  {headers:header});

Answer 4

问题在以下主题中有答案。

https://stackoverflow.com/a/45286959/12376898

https://stackoverflow.com/a/47805759/12376898

总结起来，标头是不可变的，因此进行任何更改都会创建一个新对象。除非您将新创建的对象引用到旧引用，否则只有旧对象会保留。

getLeads(jwtToken: string) {
let headers = new HttpHeaders();
headers.append('ANYHEADER','SOMESTRING') // will be lost
headers = headers.append('ANYHEADER','SOMESTRING') //unless you reference it again to the old reference
}

Angular HttpHeaders未设置值

4 个答案: