一种从上到下逐行读取文件的简单方法:
const { once } = require('events');
const { createReadStream } = require('fs');
const { createInterface } = require('readline');
let storeProducts = async () => {
try {
const filename = path.join(__dirname, "bulk-101638307937.jsonl");
const rl = createInterface({
input: createReadStream(filename),
crlfDelay: Infinity
});
rl.on('line', (line) => {
// Process the line.
console.log({line: JSON.parse(line)});
});
await once(rl, 'close');
console.log('File processed.');
} catch (err) {
console.error(err);
}
}
这很好用。但是我需要逐行向后读取一个大的 jsonl 文件 .我试过 this .它向后读取文件,但不是逐行读取。任何帮助,将不胜感激。一个示例 jsonl
{"id": 1, "product": "A"}
{"variant_id": 1, "product": "A"}
{"id": 2, "product": "B"}
{"variant_id": 2, "product": "B"}
{"id": 3, "product": "C"}
{"variant_id": 3, "product": "C"}
{"id": 4, "product": "D"}
{"variant_id": 4, "product": "D"}
{"variant_id": 5, "product": "D"}
最佳答案
图书馆fs-reverse应该做的伎俩:
const fsR = require('fs-reverse');
const filename = './sample.jsonl';
const readStream = fsR(filename, {})
readStream.on('data', (line) => {
if(line) { // have this check to make sure empty lines are not parsed
console.log(JSON.parse(line))
}
})
关于node.js - 如何在nodejs中向后读取大型json文件,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/63666544/