Node.js http2stream.pushAllowed 方法

http2stream.pushAllowed是 http2 模块中 Http2Stream 类的内置应用程序编程接口，用于检查标头是否已发送。

句法：

const http2stream.pushAllowed

参数：此方法不接受任何参数。

返回值：如果远程对等点接受推送流，则此方法返回 true，否则返回 false。

如何生成私钥和公钥证书

私钥

步骤 - 1：打开记事本并复制并粘贴以下密钥

第 2 步：另存为private-key.pem

公共证书

步骤 - 1：打开记事本并复制并粘贴以下密钥

第 2 步：另存为public-cert.pem

示例 1：文件名：index.js

// Node.js program to demonstrate the
// Http2Stream.pushAllowed method
const http2 = require('http2');
const fs = require('fs');
  
// Private key and public certificate 
// for access
const options = {
  key: fs.readFileSync('private-key.pem'),
  cert: fs.readFileSync('public-cert.pem'),
};
  
// Creating and initializing server
// by using http2.createServer() method
const server = http2.createServer(options);
  
  
server.on('stream', (stream, requestHeaders) => {
  stream.respond({ 
    ':status': 200, 
    'content-type': 'text/plain' 
  });
  
  stream.write('hello ');
  
   // Checking if header is sent or not
   // by using pushAllowed method
   const status = stream.pushAllowed;
  
   if(status)
     stream.end("push stream is accepted");
   else
     stream.end("push stream is not accepted");
  
  // Stopping the server by
  // using the close() method
  server.close(()=>{
    console.log("server destroyed");
  })
});
server.listen(8000);
  
// Creating and initializing client
// by using tls.connect() method
const client = http2.connect(
        'http://localhost:8000');
  
const req = client.request({ 
  ':method': 'GET', 
  ':path': '/' 
});
  
req.on('response', (responseHeaders) => {
    
  console.log("status : " 
    + responseHeaders[":status"]);
});
  
req.on('data', (data) => {
  
  console.log('Received: %s ',
    data.toString().replace(/(\n)/gm,""));
});
  
req.on('end', () => {
  client.close(()=>{
    console.log("client destroyed");
  })
    
});

输出：

status : 200
Received: hello
Received: push stream is accepted
client destroyed
server destroyed

使用以下命令运行 index.js 文件：

node index.js

示例 2：文件名：index.js

// Node.js program to demonstrate the
// Http2Stream.pushAllowed method
const http2 = require('http2');
const fs = require('fs');
  
// Private key and public certificate
// for access
const options = {
  key: fs.readFileSync('private-key.pem'),
  cert: fs.readFileSync('public-cert.pem'),
};
  
// Creating and initializing server
// by using http2.createServer() api
const server = http2.createServer(options);
  
  
server.on('stream', (stream, requestHeaders) => {
  
   // checking if header is sent or not
   // by using pushAllowed method
   const status = stream.pushAllowed;
  
   if(status)
      console.log("push stream is accepted");
   else
      console.log("push stream is not accepted");
  
  // Stopping the server by
  // using the close() method
  server.close(()=>{
    console.log("server destroyed");
  })
});
server.listen(8000);
  
  
// Creating and initializing client
// by using tls.connect() method
const client = http2.connect(
        'http://localhost:8000');
  
const req = client.request({ 
   ':method': 'GET', 
   ':path': '/' 
});
  
req.on('response', (responseHeaders) => {
    
  console.log("status : " 
    + responseHeaders[":status"]);
});
  
req.on('data', (data) => {
  
  console.log('Received: %s ',
    data.toString().replace(/(\n)/gm,""));
});
  
req.on('end', () => {
  client.close(()=>{
    console.log("client destroyed");
  })
    
});

输出：

push stream is accepted

使用以下命令运行 index.js 文件：

node index.js

参考： https://nodejs.org/dist/latest-v12.x/docs/api/http2.html#http2_http2stream_pushallowed