微信公众号开发总结(一) --程序入口

　　最近准备利用业务时间写一个公众号练练手，查看了微信官方文档后，发现文档内容写的非常详细，前期粗略的看了下开发指南，比以前接入的第三方接口简单多了，于是磨刀霍霍按照开发指南一步步配置服务器、申请测试账号并在线调试，轻轻松松的就接入成功。

　　下面就是我接入微信、接收微信通知的代码，写的比较粗糙，望不吝赐教.

　　引入pom依赖

<!-- https://mvnrepository.com/artifact/com.github.binarywang/weixin-java-mp -->
        <dependency>
            <groupId>com.github.binarywang</groupId>
            <artifactId>weixin-java-mp</artifactId>
            <version>3.6.0</version>
        </dependency>

　　定义 wxMpService Bean

   @Bean
    public WxMpService wxMpService() {

        WxMpService service = new WxMpServiceImpl();

        WxMpDefaultConfigImpl configStorage = new WxMpDefaultConfigImpl();
        //下面的四个参数替换成你自己的就可以了
        configStorage.setAppId(appid);
        configStorage.setSecret(secret);
        configStorage.setToken(token);
        configStorage.setAesKey(aesKey);

        Map<String, WxMpConfigStorage> config = new HashMap<> ();

        config.put(appid,configStorage);
        service.setMultiConfigges(config);
        return service;
    }    

　　

@Slf4j
@AllArgsConstructor
@RestController
@RequestMapping("/wx/portal/{appid}")
public class WxPortalController {
    @Autowired
    private WxMpService wxService;
    @Autowired
    private WxMpMessageRouter messageRouter;

    /**  验证消息 https://developers.weixin.qq.com/doc/offiaccount/Basic_Information/Access_Overview.html **/
    @GetMapping(produces = "text/plain;charset=utf-8")
    public String authGet(@PathVariable String appid,
                          @RequestParam(name = "signature", required = false) String signature,
                          @RequestParam(name = "timestamp", required = false) String timestamp,
                          @RequestParam(name = "nonce", required = false) String nonce,
                          @RequestParam(name = "echostr", required = false) String echostr) {
        log.info("
接收到来自微信服务器的认证消息：[{}, {}, {}, {}]", signature,
            timestamp, nonce, echostr);
        if (StringUtils.isAnyBlank(signature, timestamp, nonce, echostr)) {
            throw new IllegalArgumentException("请求参数非法，请核实!");
        }

        if (!this.wxService.switchover(appid)) {
            throw new IllegalArgumentException(String.format("未找到对应appid=[%s]的配置，请核实！", appid));
        }

        if (wxService.checkSignature(timestamp, nonce, signature)) {
            return echostr;
        }
        return "非法请求";
    }

    /** 事件推送 https://developers.weixin.qq.com/doc/offiaccount/Message_Management/Receiving_event_pushes.html **/ 
    @PostMapping(produces = "application/xml; charset=UTF-8")
    public String post(@PathVariable String appid,
                       @RequestBody String requestBody,
                       @RequestParam("signature") String signature,
                       @RequestParam("timestamp") String timestamp,
                       @RequestParam("nonce") String nonce,
                       @RequestParam("openid") String openid,
                       @RequestParam(name = "encrypt_type", required = false) String encType,
                       @RequestParam(name = "msg_signature", required = false) String msgSignature) {
        log.info("
接收微信请求：[openid=[{}], [signature=[{}], encType=[{}], msgSignature=[{}],"
                + " timestamp=[{}], nonce=[{}], requestBody=[
{}
] ",
            openid, signature, encType, msgSignature, timestamp, nonce, requestBody);

        if (!this.wxService.switchover(appid)) {
            throw new IllegalArgumentException(String.format("未找到对应appid=[%s]的配置，请核实！", appid));
        }

        if (!wxService.checkSignature(timestamp, nonce, signature)) {
            throw new IllegalArgumentException("非法请求，可能属于伪造的请求！");
        }

        String out = null;
        if (encType == null) {
            // 明文传输的消息
            WxMpXmlMessage inMessage = WxMpXmlMessage.fromXml(requestBody);
            WxMpXmlOutMessage outMessage = this.route(inMessage);
            if (outMessage == null) {
                return "";
            }

            out = outMessage.toXml();
        } else if ("aes".equalsIgnoreCase(encType)) {
            // aes加密的消息
            WxMpXmlMessage inMessage = WxMpXmlMessage.fromEncryptedXml(requestBody, wxService.getWxMpConfigStorage(),
                timestamp, nonce, msgSignature);
            log.info("
消息解密后内容为：
{} ", inMessage.toString());
            WxMpXmlOutMessage outMessage = this.route(inMessage);
            if (outMessage == null) {
                return "";
            }

            out = outMessage.toEncryptedXml(wxService.getWxMpConfigStorage());
        }

        log.info("
组装回复信息：{}", out);
        return out;
    }

    private WxMpXmlOutMessage route(WxMpXmlMessage message) {
        try {
            return this.messageRouter.route(message);
        } catch (Exception e) {
            log.error("路由消息时出现异常！", e);
        }
        return null;
    }

}

　　　消息验证成功后，我们就可以获取AccessToken，公众号中接口几乎都会用到这个token，但是这个token并非保持不变的，有效期2H。

 　　以上就是接入公众号的前期准备，服务器配置这些官方文档已经说的很清楚了，所以本文就没有介绍。