执行命令加载composer

composer require "paypal/rest-api-sdk-php"

页面demo

{extend name="layout/user_main" /}

{block name="content"}
<div class="pad_lr12 " style="margin-top: 5rem;">
    <a class="btn_full mar_b20 submit" href="javascript:;">check out</a>
</div>
{/block}

{block name="script"}
<script type="text/javascript">

    $('.submit').on('click',function () {
        PayPal(this);
    })

    function PayPal(obj) {
        data = {};
        data.method = 'PayPal';
        data.price = $('.method_list').find('.active').eq(0).attr('data-price');

        //创建paypal支付，生成支付链接，跳转支付
        $.ajax({
            url:"{:url('Pay/index')}",
            data:data,
            type:'post',
            success:function (re) {
                if(re.code == 1){
                    location.href = re.data.open_url;
                }else{
                    $.toast(re.msg,'text');
                }
            }
        })
    }

</script>
{/block}

使用方式

<?php

namespace app\wap\controller;

use app\wap\service\pay\PayPal;

class Pay extends Base
{
    /**
     * PayPal支付
     * 1.保存支付信息
     * 2.判断用户等级是否需要升级
     */
    public function index()
    {
        $param = $this->request->param();
        if(!isset($param['method']) || !isset($param['price'])){
            $this->error('request was aborted');
        }

        //生成订单
        ...
        //创建支付
        try{
            $paypal = new PayPal();
            $result = $paypal->createPayPal($data);
            if($result['code'] == 0){
                $this->error($result['msg']);
            }
        }catch(\Exception $e){
            $this->error($e->getMessage());
        }
        //跳转到支付确认
        $this->success('success','',$result['data']);
    }

    /**
     * 执行付款
     * return data array(3) {
    ["paymentId"] => string(28) "PAY-65076081CX802152WLLZIO4I"  //支付ID
    ["token"] => string(20) "EC-8N633353AD2775827"
    ["PayerID"] => string(13) ""                   //付款人ID
    }
     */
    public function paysuccess()
    {
        $param = $this->request->param();
        try{
            //执行paypal支付
            $paypal = new PayPal();
            $orderInfo = $paypal->payment($param);
            $this->paySuccessLogic($orderInfo);
        }catch(\Exception $e){
            $this->error($e->getMessage());
        }
    }

    //付款成功后的处理逻辑
    public function paySuccessLogic($orderInfo)
    {
        ...
        $this->success('Recharge success',url('User/index'),'',10);
    }

}

paypal支付逻辑处理

<?php

namespace app\wap\service\pay;

require EXTEND_PATH.'lib/PayPalUtil.php';


/**
 * PayPal支付
 */
class PayPal
{
    protected $config;

    public function __construct()
    {
        parent::__construct();
        //获取paypal支付配置
        $info = model('Payment')->getPayInfo(['pay_code'=>'PayPal','enabled'=>1]);
        if(!$info){
            throw new \Exception('Sorry, the way of payment is not supported');
        }
        $this->config = json_decode($info->toArray()['pay_config'],true);
    }

    //创建PayPal支付
    public function createPayPal($data)
    {
        //支付成功跳转地址
        $successUri = url('Pay/paysuccess','','html',true);
        //支付失败跳转地址
        $errorUri = url('User/recharge','','html',true);
        //调用支付工具类创建支付信息
        $payPal = new \ext\lib\PayPalUtil($this->config,$data['money'],$data['order_sn'],$successUri,$errorUri);
        $result = $payPal->pay();
        
        return $result;
    }

    //执行付款
    public function payment($param)
    {
        //调用支付工具类支付
        $payPal = new \ext\lib\PayPalUtil($this->config);
        $result = $payPal->payment($param['paymentId'],$param['token'],$param['PayerID']);
        if($result['code'] == 0){
            throw new \Exception('Failure to pay');
        }
        //判断是否是经批准的
        if($result['data']->state != 'approved'){
            throw new \Exception('Failure to pay');
        }

        $orderSn = $result['data']->transactions[0]->invoice_number;
        $orderInfo = model('UserRecharge')->where(['order_sn'=>$orderSn])->find();
        if(!$orderInfo){
            //TODO:数据库订单不存在，支付异常,给用户退款file_put_contents('./recharge.log',json_encode($result).PHP_EOL,FILE_APPEND);
            throw new \Exception('Failure to pay');
        }
        //支付成功，进行后续处理
        $orderInfo->pay_id = $result['data']->id;
        $orderInfo->cart = $result['data']->cart;
        $orderInfo->save();

        return $orderInfo;
    }

paypal支付工具类

<?php
/**
 * PayPal支付工具类.
 * User: Victory
 * Date: 2018/5/5 0005
 * Time: 12:39
 */

namespace ext\lib;

use PayPal\Rest\ApiContext;
use PayPal\Auth\OAuthTokenCredential;
use PayPal\Api\Payer;
use PayPal\Api\Item;
use PayPal\Api\ItemList;
use PayPal\Api\Details;
use PayPal\Api\Amount;
use PayPal\Api\Transaction;
use PayPal\Api\RedirectUrls;
use PayPal\Api\Payment;
use PayPal\Exception\PayPalConnectionException;
use PayPal\Api\PaymentExecution;
use think\Controller;

class PayPalUtil extends Controller
{
    public $config = [];
    public $price = 0;
    public $orderSn = 0;
    public $redirectUrl = '';
    public $cancelUrl = '';
    public $apiContext = '';

    public function __construct($config,$price = '',$orderSn = '',$redirectUrl = '',$cancelUrl = '')
    {
        parent::__construct();
        $this->config = $config;
        $this->price = $price;
        $this->orderSn = $orderSn;
        $this->redirectUrl = $redirectUrl;
        $this->cancelUrl = $cancelUrl;
//        dump($this->config);
        //实例化paypal支付api环境类
        $this->apiContext = new ApiContext(
            new OAuthTokenCredential(
                $this->config['client_id'],     // ClientID
                $this->config['client_secret']      // ClientSecret
            )
        );
        $this->apiContext->setConfig(['mode'=>'live']);
    }

    //使用PayPal创建付款作为付款方式
    public function pay()
    {
        //付款人
        $payer = new Payer();
        //设置付款方式为paypal
        $payer->setPaymentMethod('paypal');

        /*$item = new Item();                         //项目详情类。
        $item->setName('Recharge of a novel member')                    //项目名称
            ->setCurrency($this->config['currency'])                    //设置货币
            ->setQuantity(1)                        //设置量
            ->setPrice($this->price);                     //设置金额

        $itemList = new ItemList();                 //支付物品清单。
        $itemList->setItems([$item]);               //项目清单。*/

        /*$details = new Details();                   //支付金额的其他细节。
        $details->setShipping(0)            //运费收取金额
            ->setSubtotal($this->price);                  //项目的小计金额。**如果指定了行项目，则需要***/

        $amount = new Amount();
        $amount->setTotal($this->price);                  //设置支付金额
        $amount->setCurrency($this->config['currency']);                //设置支付货币


        $transaction = new Transaction();           //交易定义了付款合同 - 付款和完成付款的人是什么。
        $transaction->setAmount($amount)            //正在收集的数量。
//            ->setItemList($itemList)                //支付物品清单。
            ->setDescription("Member recharge VIP")         //支付描述内容
            ->setInvoiceNumber($this->orderSn);           //设置发票号码


        $redirectUrls = new RedirectUrls();         //设置重定向的URL你只提供贝宝支付。

        $redirectUrls->setReturnUrl($this->redirectUrl)       //URL，支付者将被重定向到批准支付后。*贝宝账户支付所需的**。
            ->setCancelUrl($this->cancelUrl);                 //在支付取消后，付款人将被重定向到的URL。*贝宝账户支付所需的**。

        //创建，处理和管理付款类。
        $payment = new Payment();
        $payment->setIntent('sale')                             //付款意向。
            ->setPayer($payer)                                  //该支付的贝宝账户或直接信用卡为代表的资金来源
            ->setTransactions(array($transaction))              //交易细节，包括数量和项目细节。
            ->setRedirectUrls($redirectUrls);                   //设置重定向的URL你只提供贝宝支付。
        try {
            $payment->create($this->apiContext);                      //创建和处理支付。在JSON请求主体中，包含带有意图、付款人和事务的“支付”对象。贝宝付款，包括重定向的URL在`支付`对象。
        } catch (PayPalConnectionException $ex) {
            // This will print the detailed information on the exception.
            //REALLY HELPFUL FOR DEBUGGING
//            echo $ex->getData();
            return ['code'=>0,'msg'=>'code:'.$ex->getCode().',msg:'.$ex->getData(),'data'=>''];
        }
        $approvalUrl = $payment->getApprovalLink();             //获得批准支付链接
        return ['code'=>1,'msg'=>'success','data'=>['open_url'=>$approvalUrl]];
    }

    //执行付款
    public function payment($paymentId,$token,$PayerID){

        $payment = Payment::get($paymentId, $this->apiContext);   //通过ID显示付款细节
        $execution = new PaymentExecution();
        $execution->setPayerId($PayerID);       //设置付款人ID
        try {
            $result = $payment->execute($execution, $this->apiContext);   //执行付款,执行或完成，贝宝付款，付款人已批准。当您执行支付时，您可以选择性地更新选择性支付信息。
            try {
                $payment = Payment::get($paymentId, $this->apiContext);//通过ID显示付款细节
            } catch (\Exception $ex) {
                return ['code'=>0,'msg'=>'Failure to pay1','data'=>''];
            }
        }catch (\Exception $ex) {
            return ['code'=>0,'msg'=>'Failure to pay2','data'=>''];
        }
        return ['code'=>1,'msg'=>'success','data'=>$payment];
    }
}