Question

有时我在尝试使用请求模块获取请求时出错码： const request = require（'request'）;

getRequest("sitelink", {'Content-Type': 'application/json'}, null, proxy,
function(data, res){
  log(data);
});

function getRequest(url, headers, setEncoding, proxy, onResult) {
    var r = request;
    if(proxy != null) r = request.defaults({'proxy':'http://' + proxy});
    else r = request;
    r({method: 'GET', url: url, headers: headers, encoding: (setEncoding == null ? 'UTF-8' : setEncoding)}, 
    function (error, response, body) {
        if (!error && response.statusCode == 200) {
            onResult(body, response);
            return;
        } else log(error);
    });
};

错误日志：

> Error [ERR_HTTP_HEADERS_SENT]: Cannot set headers after they are sent
> to the client
>     at ServerResponse.setHeader (_http_outgoing.js:469:11)
>     at ServerResponse.header (/root/bot/node_modules/express/lib/response.js:767:10)
>     at ServerResponse.send (/root/bot/node_modules/express/lib/response.js:170:12)
>     at /root/bot/start.js:1381:12
>     at Request._callback (/root/bot/start.js:1503:4)
>     at Request.self.callback (/root/bot/node_modules/request/request.js:185:22)
>     at Request.emit (events.js:182:13)
>     at Request.EventEmitter.emit (domain.js:442:20)
>     at Request.<anonymous> (/root/bot/node_modules/request/request.js:1161:10)
>     at Request.emit (events.js:182:13)

Answer 1

当您的应用通过HTTP对客户端进行响应时，会发生此错误，并且您尝试两次发送响应/响应标头。发送响应后，连接将关闭。对于给定的http请求，您只能发送一次。您可以保持连接打开并发送更多数据，但是不能再次发送响应头。

NODEJS [ERR_HTTP_HEADERS_SENT]：将标头发送到客户端后无法设置标头

1 个答案: