Android集成微信支付

Android集成微信支付
微信支付和支付寶支付一樣的，都可以在客戶端發起支付併成功通過，但這樣做的漏洞比較大，所以一定不要通過客戶端直接來完成

1.首先需要 在客戶端向服務器發起一個微信預支付操作：

請求參數如下：

body.put("loginUserId", loginUserId );
body.put("title", title);
body.put("business", business);
body.put("orderId", orderId);
body.put("charges", charges); //  注意這裏的金額是要在實際金額*100
body.put("employeeId", employeeId);
body.put("WXAppId", Const.WX_APP_ID);

微信預支付操作處理後可以從微信服務器獲取一個預支付id，然後再通過預支付id真正發起微信支付操作.

 WXPayUtil payUtil = new WXPayUtil(mActivity);
 payUtil.doPayReq(bean.prepay_id);
 ```



 具體代碼放一下，反正也沒有什麼機密

 ```
 public class WXPayUtil {
    private PayReq req = null;
    private IWXAPI msgApi = null;
    private StringBuffer sb = null;


    public WXPayUtil(final Activity activity) {
        this.req = new PayReq();
        this.msgApi = WXAPIFactory.createWXAPI(activity, null);
        this.msgApi.registerApp(Constants.APP_ID);
        this.sb = new StringBuffer();
    }


    /**
     * @work:生成簽名參數
     * @date:2015-9-7 上午11:48:04
     * @author:[email protected]
     * @params:
     */
    public void doPayReq(String prePayId) {
        req.appId = Constants.APP_ID;
        req.partnerId = Constants.MCH_ID;
        req.prepayId = prePayId;
        req.packageValue = "Sign=WXPay";
        req.nonceStr = genNonceStr();
        req.timeStamp = String.valueOf(genTimeStamp());
        List<NameValuePair> signParams = new LinkedList<>();
        signParams.add(new BasicNameValuePair("appid", req.appId));
        signParams.add(new BasicNameValuePair("noncestr", req.nonceStr));
        signParams.add(new BasicNameValuePair("package", req.packageValue));
        signParams.add(new BasicNameValuePair("partnerid", req.partnerId));
        signParams.add(new BasicNameValuePair("prepayid", req.prepayId));
        signParams.add(new BasicNameValuePair("timestamp", req.timeStamp));
        req.sign = genAppSign(signParams);
        sb.append("sign\n" + req.sign + "\n\n");
        sendPayReq();
    }

    /**
     * @work:啓動支付
     * @date:2015-9-7 上午11:49:51
     * @author:[email protected]
     */
    private void sendPayReq() {
        msgApi.registerApp(Constants.APP_ID);
        msgApi.sendReq(req);
    }

    private String genAppSign(List<NameValuePair> params) {
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < params.size(); i++) {
            sb.append(params.get(i).getName());
            sb.append('=');
            sb.append(params.get(i).getValue());
            sb.append('&');
        }
        sb.append("key=");
        sb.append(Constants.API_KEY);

        this.sb.append("sign str\n" + sb.toString() + "\n\n");
        String appSign = MD5.getMessageDigest(sb.toString().getBytes()).toUpperCase();
        return appSign;
    }

    private String genNonceStr() {
        Random random = new Random();
        return MD5.getMessageDigest(String.valueOf(random.nextInt(10000)).getBytes());
    }

    private long genTimeStamp() {
        return System.currentTimeMillis() / 1000;
    }

然後微信的操作如下：

public class WXPayEntryActivity extends Activity implements IWXAPIEventHandler{

    /***微信支付結果*/
    public static int mWXPayResult = -1;

    private static final String TAG = "MicroMsg.SDKSample.WXPayEntryActivity";

    private IWXAPI api;


    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.pay_result);

        api = WXAPIFactory.createWXAPI(this, Constants.APP_ID);

        api.handleIntent(getIntent(), this);
    }

    @Override
    protected void onNewIntent(Intent intent) {
        super.onNewIntent(intent);
        setIntent(intent);
        api.handleIntent(intent, this);
    }

    @Override
    public void onReq(BaseReq req) {
    }

    @Override
    public void onResp(BaseResp resp) {

        if (resp.getType() == ConstantsAPI.COMMAND_PAY_BY_WX) {

            mWXPayResult = resp.errCode;

            if (resp.errCode == 0) //支付成功，
            {   
                BToast.show(this, "支付成功!");
                finish();
            } else if(resp.errCode == -1) { //支付失敗
                BToast.show(this, "支付錯誤");
                finish();
            }else if(resp.errCode == -2){//取消支付
                BToast.show(this, "您已經取消了支付！");
                finish();
            }
        }
    }
}

這裏我有一個全局靜態變量mWXPayResult來標記微信支付是否成功的狀態.

  mPayBean.payResult = WXPayEntryActivity.mWXPayResult == 0;
                if (mPayBean.payResult) {
                    doSubmit();
                } 

這個時候微信支付就處理完畢.