node 怎样把stream 转成buffer对象?
问题太短了 我没太理解,我就按照我自己的想法和你说一下
如果不用piping的话,你需要监听你stream的data
和end
事件
下面是将一个文件的读流,转成buffer,然后写到别的文件里面去
const readStream = fs.createReadStream(path.join(__dirname, 'xxx.txt'))
const buffers = [];
readStream.on('data', function(buffer) {
buffers.push(buffer);
});
readStream.on('end', function() {
const data = Buffer.from(buffers);
//...do your stuff...
// such as write to file:
fs.writeFile('xxx.txt', data, function(err) {
// handle error, return response, etc...
});
});
readStream.on('error', function(error){
console.error('readStream error:', error.message);
})
不过最好推荐使用pip方式,这样如果读的buffer很大的话,对内存会有压力,pip不会
const readStream = fs.createReadStream(path.join(__dirname, './xxx_read.json'))
const writeStream = fs.createWriteStream(path.join(__dirname, './xxx_write.json'))
readStream.pipe(writeStream)
readStream.on('error', (error) => {
console.log('readStream error', error.message);
})
writeStream.on('error', (error) => {
console.log('writeStream error', error.message);
})