app.js

const express = require('express');
const multer = require('multer');
const path = require('path');
const app = express();
var AWS = require('aws-sdk');
var Async = require('async');
var fs = require('fs');
// Create an S3 client
var s3 = new AWS.S3();
AWS.config.update({
	region: "us-east-1"
});
var docClient = new AWS.DynamoDB.DocumentClient();

var dynamodb = new AWS.DynamoDB();
app.use(express.static('./public'));


const storage = multer.diskStorage({
	destination: function(req, file, cb) {
		cb(null, path.resolve('public/uploads'));
	},
	filename: function(req, file, cb) {
		cb(null, Date.now() + path.extname(file.originalname));
	}
});

function getDesc(da, cb) {
	var desc = [];
	for (var i = 0; i < da.Contents.length; i++) {
		var pics = {};
		pics['picname'] = da.Contents[i].Key;
		pics['desc'] = '';
		console.log(pics.picname)
		var params = {
			'TableName': 'pictureslabel',
			'Key': {
				'year': 2019,
				'picname': pics.picname
			}
		};

		desc.push(pics);
	}
	var query = {
		TableName: "hejiewei",
		Limit: 1000
	};

	dynamodb.scan(query, function(err, data) {

			console.log("啊" + JSON.stringify(data));
			var Items = data.Items;
			for (var i = 0; i < desc.length; i++) {
				for (var j = 0; j < data.Count; j++) {
					console.log(desc[i].picname)
					console.log(Items[j].picname)
					if (desc[i].picname == Items[j].picname.S) {
						desc[i].desc = Items[j].desc.S;
					}
				}
			}
			console.log(desc)
			cb(null, desc);
		}

	)
}

const upload = multer({
	storage: storage
});
app.post('/getpic', function(req, res, next) {
	Async.waterfall([
		function(cb) {
			let getParams = {
				Bucket: 'hejiewei',
			};
			s3.listObjectsV2(getParams, function(err, da) {
				cb(err, da)
			});
		},
		function(da, cb) {

			getDesc(da, function(err, picD) {
				console.log("picD" + picD);
				cb(err, picD);
			})
		}
	], function(err, picD) {
		if (err) {
			console.log("错误" + err);
			res.send(err);
		} else {
			var datas = [];
			console.log(picD.length)
			var prefix = 'https://hejiewei.s3.amazonaws.com/'
			for (var i = 0; i < picD.length; i++) {
				var data = {};
				data['pic'] = prefix + picD[i].picname;
				data['desc'] = picD[i].desc;
				datas.push(data);
			}
			res.send(datas);
		}
	});

})
app.post('/profile', upload.single('avatar'), function(req, res, next) {
	console.log(req.file.originalname);
	var text = req.body.desc;

	var params = {
		Item: {
			"picname": {
				S: req.file.originalname
			},
			"desc": {
				S: text
			}
		},
		ReturnConsumedCapacity: "TOTAL",
		TableName: "hejiewei"
	};
	dynamodb.putItem(params, function(err, data) {
		if (err) {
			console.error("Unable to add item. Error JSON:", JSON.stringify(err, null, 2));
		} else {
			console.log("Added item:", JSON.stringify(data, null, 2));
		}
	});
	fs.readFile(req.file.path, function(err, data) {
		if (err) {
			throw err;
		}

		s3.putObject({
			Bucket: 'hejiewei',
			Key: req.file.originalname,
			Body: data,
			ContentType: 'image/jpeg',
			ACL: 'public-read'
		}, function(err, data) {
			if (err) console.log(err, err.stack);
			else
				console.log('Successfully uploaded package.');
		});
	});

	res.send({
		err: null,
		filePath: 'uploads/' + path.basename(req.file.path)
	});
});


app.listen(3000, function() {
	console.log("app is listening");
});