在此页

• 句法
• 范例
• 规范
• 浏览器兼容性
• 另请参阅
• 相关话题

XMLHttpRequest 方法 getAllResponseHeaders() returns all the response headers, separated by CRLF , as a string, or returns null 若未收到响应。 If a network error happened, an empty string is returned.

注意： For multipart requests, this returns the headers from the current part of the request, not from the original channel.

句法

var headers = XMLHttpRequest.getAllResponseHeaders();
					

参数

None.

返回值

A ByteString representing all of the response's headers (except those whose field name is Set-Cookie or Set-Cookie2 ) separated by CRLF ，或 null if no response has been received. If a network error happened, an empty string is returned.

An example of what a raw header string looks like:

date: Fri, 08 Dec 2017 21:04:30 GMT\r\n
content-encoding: gzip\r\n
x-content-type-options: nosniff\r\n
server: meinheld/0.6.1\r\n
x-frame-options: DENY\r\n
content-type: text/html; charset=utf-8\r\n
connection: keep-alive\r\n
strict-transport-security: max-age=63072000\r\n
vary: Cookie, Accept-Encoding\r\n
content-length: 6502\r\n
x-xss-protection: 1; mode=block\r\n
					

Each line is terminated by both carriage return and line feed characters ( \r\n ). These are essentially delimiters separating each of the headers.

注意 : In modern browsers, the header names are returned in all lower case, as per the latest spec.

范例

This example examines the headers in the request's readystatechange event handler, XMLHttpRequest.onreadystatechange . The code shows how to obtain the raw header string, as well as how to convert it into an array of individual headers and then how to take that array and create a mapping of header names to their values.

var request = new XMLHttpRequest();
request.open("GET", "foo.txt", true);
request.send();
request.onreadystatechange = function() {
  if(this.readyState == this.HEADERS_RECEIVED) {
    // Get the raw header string
    var headers = request.getAllResponseHeaders();
    // Convert the header string into an array
    // of individual headers
    var arr = headers.trim().split(/[\r\n]+/);
    // Create a map of header names to values
    var headerMap = {};
    arr.forEach(function (line) {
      var parts = line.split(': ');
      var header = parts.shift();
      var value = parts.join(': ');
      headerMap[header] = value;
    });
  }
}
					

Once this is done, you can, for example:

var contentType = headerMap["content-type"];
					

This obtains the value of the Content-Type header into the variable contentType .

规范

规范	状态	注释
XMLHttpRequest The definition of 'getAllResponseHeaders()' in that specification.	实时标准	WHATWG (Web 超文本应用程序技术工作组) 实时标准

浏览器兼容性

The compatibility table in this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request. 更新 GitHub 上的兼容性数据

	桌面						移动
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
getAllResponseHeaders	Chrome 1	Edge 12	Firefox 4 注意事项 4 注意事项 Starting from Firefox 49, empty headers are returned as empty strings in case the preference network.http.keep_empty_response_headers_as_empty_string 被设为 true ，默认为 false . Before Firefox 49 empty headers had been ignored. Since Firefox 50 the preference defaults to true .	IE 5	Opera Yes	Safari 1.2	WebView Android Yes	Chrome Android Yes	Firefox Android 4 注意事项 4 注意事项 Starting from Firefox 49, empty headers are returned as empty strings in case the preference network.http.keep_empty_response_headers_as_empty_string 被设为 true ，默认为 false . Before Firefox 49 empty headers had been ignored. Since Firefox 50 the preference defaults to true .	Opera Android Yes	Safari iOS Yes	Samsung Internet Android Yes
Header names returned in all lower case	Chrome Yes	Edge 79	Firefox 64	IE 不支持 No	Opera Yes	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android 64	Opera Android Yes	Safari iOS Yes	Samsung Internet Android Yes

图例

完整支持

完整支持

不支持

不支持

见实现注意事项。

另请参阅

• 使用 XMLHttpRequest
• Setting request headers: setRequestHeader()

元数据

• 最后修改： Nov 30, 2019

相关话题

1. XMLHttpRequest
2. 构造函数

   1. XMLHttpRequest()
3. 特性

   1. channel
   2. mozAnon
   3. mozBackgroundRequest
   4. mozResponseArrayBuffer
   5. mozSystem
   6. multipart
   7. onreadystatechange
   8. readyState
   9. response
   10. responseText
   11. responseType
   12. responseURL
   13. responseXML
   14. status
   15. statusText
   16. timeout
   17. upload
   18. withCredentials
4. 方法

   1. abort()
   2. getAllResponseHeaders()
   3. getResponseHeader()
   4. open()
   5. openRequest()
   6. overrideMimeType()
   7. send()
   8. sendAsBinary()
   9. setRequestHeader()
5. 事件

   1. onreadystatechange
   2. abort
   3. error
   4. load
   5. loadend
   6. loadstart
   7. progress
   8. timeout
6. 继承：

   1. XMLHttpRequestEventTarget
   2. EventTarget
7. XMLHttpRequest 相关页面

   1. FormData
   2. XMLHttpRequestEventTarget
   3. XMLHttpRequestUpload