Using node to call Alipay payment interface

In this article, I will briefly introduce the use of Alipay sandbox in node.

1. Start

First register Alipay open platform account: https://open.alipay.com/
After successful login, click to enter the management center
After entering successfully, select the console option, and then click R & D service to enter.
Wait in the sandbox application interface and come back later

2. Generate key

It is also necessary to download an application to generate Alipay payment key. https://opendocs.alipay.com/common/02kipl , there are two versions of window s and mac, which can be downloaded and installed on your own computer (just click Next and select a folder to install)
After installation, go to the following page:
Choose the most commonly used RSA2 encryption algorithm, which is an algorithm invented by MIT and has not been broken through in decades. Then there are two choices: pkcs8 (for Java) and pkcs1 (for non Java). Because I want to demonstrate with node, I don't use Java, and I don't install the Java environment, I choose the second pkcs1 (for non Java).
Click generate key to generate public key and private key.
Then click the copy public key button to return to the sandbox environment interface and select the option of user-defined key in the development information. Then click the button behind the RSA2 key (recommended).
On the pop-up signature management page, select the public key option, paste the public key in the application that just generated the key into the following input box, and then click Save settings.
Adding the key is complete.

3. Initialize project

Here is the first official document to Alipay: https://www.yuque.com/chenqiu/alipay-node-sdk/config-sdk , you can save it and have a look when you want to study in the future.

Create a new folder and open it with an editor
First initialize the whole project, open the control panel under the root directory of the folder, and enter npm init -y to initialize the whole folder.
Then download a very important module, which is Alipay's SDK, and input the command: npm install alipay-sdk -S.
Because the node i will write later will use the express framework, I will install the express framework again: npm install express -S

4. Code writing

Here I will post the complete code, and I will explain each piece of information to be used

//Introducing alipay sdk module
const AliPaySdk = require('alipay-sdk').default

//Introducing Alibaba pay form module
const AlipayForm = require('alipay-sdk/lib/form').default

//Introducing express framework
const express = require('express')

// Instantiation framework
const app = express()

// Middleware introducing framework
const router = express.Router()

// mount 
app.use('/api', router)

//Initialize alipay configuration
const alipaySdk = new AliPaySdk({
    appId: '', // Own id
    gateway:"https://openapi.alipaydev.com/gateway.do, / / this is Alipay's official website sandbox test gateway.
    privateKey: "", // Apply private key
    alipayPublicKey: "" // Alipay public key
})
 
// Server send request
router.get('/pay', async (req, res) => {
  // Instantiate AlipayForm
    const formData = new AlipayForm()

    // The following is the test code of the official website
    formData.setMethod('get')
    formData.addField('returnUrl', 'http://www.baidu.com '); / / successful payment callback
    formData.addField('bizContent', {
        outTradeNo: Math.random(), // order number
        productCode: 'FAST_INSTANT_TRADE_PAY', // Product code
        totalAmount: '499999', // Commodity amount
        subject: 'Cool knowledge', // Title of goods sold
        body: 'My knowledge' // Content of goods sold
    });
  
    //results of enforcement
    const reult = await alipaySdk.exec('alipay.trade.page.pay',{},{ formData: formData })

    // Returns data in json format
    res.json({
      code: reult
    })
})

// Turn on the server to listen
app.listen(8080, () => {
  console.log('success, http://localhost:8080/api/pay')
})

I'll introduce it step by step

The first is to introduce several important modules

//Introducing alipay sdk module
const AliPaySdk = require('alipay-sdk').default

//Introducing Alibaba pay form module
const AlipayForm = require('alipay-sdk/lib/form').default

//Introducing express framework
const express = require('express')

// Instantiation framework
const app = express()

// Middleware introducing framework
const router = express.Router()

// mount 
app.use('/api', router)

The AliPaySdk and AlipayForm introduced are what we install in Alipay sdk module. Note that the property of.default should be added after each module.
② The last four lines of code are all the things of the express framework I introduced. It doesn't matter if I can't understand it. Just put it here

The following configuration is more important. This is the initial configuration of Alipay payment. Note that the key words can not be modified by itself, and I will explain the value that I want to input later.
```
//Initialize alipay configuration
const alipaySdk = new AliPaySdk({
	appId: '', // Own id
	gateway:"https://openapi.alipaydev.com/gateway.do, / / this is Alipay's official website sandbox test gateway.
	privateKey: "", // Apply private key
	alipayPublicKey: "" // Alipay public key
})
```
AppId: This is the id in the Alipay development platform, copying the id into the appId of the code.
gateway: This is Alipay official payment test network officer.
③ privateKey: This is the private key. Open the application that generated the key before, copy the private key and paste it into the privateKey of the code.
AlipayPublicKey: Alipay public key, open the public key that we set up in the Alipay open platform, then copy the public key and paste it into the alipayPublicKey of the code.

The following is the request for Alipay payment, which is written in official documents: https://www.yuque.com/chenqiu/alipay-node-sdk/page_api

// Server send request
router.get('/pay', async (req, res) => {

	// Instantiate AlipayForm
	const formData = new AlipayForm()

	// The following is the test code of the official website
	formData.setMethod('get')
	formData.addField('returnUrl', 'http://www.baidu.com'); // Callback of successful payment
	formData.addField('bizContent', {
   		outTradeNo: Math.random(), // order number
   		productCode: 'FAST_INSTANT_TRADE_PAY', // Product code
    	totalAmount: '9.89', // Commodity amount
    	subject: 'Good time goods~', // Title of goods sold
    	body: 'Clothes sale' // Content of goods sold
	});

  	//results of enforcement
 	const reult = await alipaySdk.exec('alipay.trade.page.pay',{},{ formData: formData })

 	// Returns data in json format
	res.json({
		code: reult
 	})
})

This is the fixed code. There is no need to change the code. Here I say two points:
① Code formdata. Addfield ('returnurl ',' http://www.baidu.com ', the second parameter is the website to jump to after the payment of goods is successful.
② Code outTradeNo: Math.random(), which is used to write the order number. The order number of each commodity is unique. When the commodity is paid, the order number can no longer be used. Therefore, I use a Math.random number to generate one at a time, which is a random number

5. Pay for goods

Open the server node pay.js
Open the open server, and then open the page as follows. Copy a string of addresses after the code, and then open it in the page
Note that if you open it in the current browser, the following page will appear:
This is because the current browser is not safe enough to open. At this time, copy the address of this page, open a new browser (I use Edge browser to open it here), and open this address again
Log in to Alipay's account name and password. The account name and password are in the sandbox account of the open platform, because here I use the interface of payment, that is, we are the buyer, so we can find the buyer's information and paste the account number and password into the browser's input box.
Then buy the goods.
If the account money is not enough, go to the sandbox account to recharge, with a maximum of 999999.99 at a time
Of course, it's all money for testing. It's impossible to take it out. You can experience the pleasure of spending money.