Node.js http.ServerResponse.headersSent用法及代碼示例

httpServerResponse.headersSent是HTTP模塊內的ServerResponse類的內置應用程序編程接口，用於檢查標頭是否已發送。

用法:

const response.headersSent

參數：此屬性不接受任何參數作為參數。

返回值：當且僅當發送標頭時，此屬性返回true，否則返回false。

範例1：Filename-index.js

Javascript

// Node.js program to demonstrate the   
// response.headersSent() method 
  
// Importing http module  
var http = require('http'); 
  
// Setting up PORT  
const PORT = process.env.PORT || 3000; 
  
// Creating http Server  
var httpServer = http.createServer( 
    function (request, response) { 
  
    // Checking if response header is sent or not 
    // by using headersSent method 
    const value = response.headersSent; 
  
    // Display result by using end() method 
    response.end("Headers have been sent:"
                   + value, 'utf8', () => { 
        console.log("displaying the result..."); 
  
        httpServer.close(() => { 
            console.log("server is closed") 
        }) 
    }); 
}); 
  
// Listening to http Server  
httpServer.listen(PORT, () => { 
    console.log("Server is running at port 3000..."); 
});

使用以下命令運行index.js文件：

node index.js

輸出：

Server is running at port 3000...
displaying the result...
server is closed

現在打開瀏覽器並轉到http：//localhost：3000 /，您將看到以下輸出：

Headers have been sent:false

示例2：Filename-index.js

Javascript

// Node.js program to demonstrate the   
// response.headersSent() method 
  
// Importing http module  
var http = require('http'); 
  
// Request and response handler  
const httpHandlers = (request, response) => { 
  
    // Checking if response header is sent or not 
    // by using headersSent method 
    const value = response.headersSent; 
  
    // Display result by using end() method 
    response.end("Headers have been sent:"
                      + value, 'utf8', () => { 
        console.log("displaying the result..."); 
  
        httpServer.close(() => { 
            console.log("server is closed") 
        }) 
    }); 
}; 
  
// Creating http Server  
var httpServer = http.createServer( 
    httpHandlers).listen(3000, () => { 
    console.log("Server is running at port 3000..."); 
});

使用以下命令運行index.js文件：

node index.js

輸出：

Server is running at port 3000...
displaying the result...
server is closed

現在打開瀏覽器並轉到http：//localhost：3000 /，您將看到以下輸出：

Headers have been sent:false

參考： https://nodejs.org/dist/latest-v12.x/docs/api/http.html#http_response_headerssent

相關用法

注：本文由純淨天空篩選整理自RohitPrasad3大神的英文原創作品 Node.js http.ServerResponse.headersSent Property。非經特殊聲明，原始代碼版權歸原作者所有，本譯文未經允許或授權，請勿轉載或複製。