uniapp打包H5在微信浏览器中调用公众号登录获得Openid
1.申请一个公众号

地址：https://mp.weixin.qq.com/

2.公众号配置
2.1.在进入公众号后台后，在左边侧边栏找到基本配置，就可以看到APPID与AppSecret
2.2.配置服务器配置：在APPID与AppSecret页面下有一个服务器配置，需要配置，配置中的token是一个坑，需要先写验证请求才能把token配置成功。图片里的工具了在下面代码中，具体如图：

2.3. 添加页面授权（也就是在那个页面可以调起登录，一般设置为域名即可）

2.4在接口权限中找到

3.需要的包

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter</artifactId>
		</dependency>
		<dependency>
			<groupId>org.projectlombok</groupId>
			<artifactId>lombok</artifactId>
			<optional>true</optional>
		</dependency>
		<!--网络链接-->
		<dependency>
			<groupId>org.apache.httpcomponents</groupId>
			<artifactId>httpclient</artifactId>
			<version>4.5.12</version>
		</dependency>
		<!--json处理-->
		<dependency>
			<groupId>com.alibaba</groupId>
			<artifactId>fastjson</artifactId>
			<version>1.2.60</version>
		</dependency>

4.编写验证token的工具类

package com.taxing.wxopenid.utills;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

/**
 * 签名认证工具类
 * @ClassName:  WeixinCheckoutUtil
 *
 */
public class WeixinCheckoutUtil {
	// 与接口配置信息中的Token要一致
    private static String token = "2fdf28s0fhdfgsf26aff84159753";
    /**
     * 验证签名
     *
     * @param signature
     * @param timestamp
     * @param nonce
     * @return
     */
    public static boolean checkSignature(String signature, String timestamp, String nonce) {
        String[] arr = new String[] { token, timestamp, nonce };
        // 将token、timestamp、nonce三个参数进行字典序排序
        // Arrays.sort(arr);
        sort(arr);
        StringBuilder content = new StringBuilder();
        for (int i = 0; i < arr.length; i++) {
            content.append(arr[i]);
        }
        MessageDigest md = null;
        String tmpStr = null;
        try {
            md = MessageDigest.getInstance("SHA-1");
            // 将三个参数字符串拼接成一个字符串进行sha1加密
            byte[] digest = md.digest(content.toString().getBytes());
            tmpStr = byteToStr(digest);
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        }
        content = null;
        // 将sha1加密后的字符串可与signature对比，标识该请求来源于微信
        return tmpStr != null ? tmpStr.equals(signature.toUpperCase()) : false;
    }
    /**
     * 将字节数组转换为十六进制字符串
     *
     * @param byteArray
     * @return
     */
    private static String byteToStr(byte[] byteArray) {
        String strDigest = "";
        for (int i = 0; i < byteArray.length; i++) {
            strDigest += byteToHexStr(byteArray[i]);
        }
        return strDigest;
    }

    /**
     * 将字节转换为十六进制字符串
     * @param mByte
     * @return
     */
    private static String byteToHexStr(byte mByte) {
        char[] Digit = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };
        char[] tempArr = new char[2];
        tempArr[0] = Digit[(mByte >>> 4) & 0X0F];
        tempArr[1] = Digit[mByte & 0X0F];
        String s = new String(tempArr);
        return s;
    }
    public static void sort(String a[]) {
        for (int i = 0; i < a.length - 1; i++) {
            for (int j = i + 1; j < a.length; j++) {
                if (a[j].compareTo(a[i]) < 0) {
                    String temp = a[i];
                    a[i] = a[j];
                    a[j] = temp;
                }
            }
        }
    }
}

5.编写验证token的controller

/**
	 * 微信公众号签名认证接口
	 * @Title: test
	 * @throws
	 */
	@RequestMapping("/wx")
	public String test(String signature,String timestamp,String nonce,String echostr) {
        // 通过检验signature对请求进行校验，若校验成功则原样返回echostr，表示接入成功，否则接入失败
		 if (signature != null && WeixinCheckoutUtil.checkSignature(signature, timestamp, nonce)) {
           return echostr;
         }
		return null;
	}

6.微信内浏览器获得openid

@RequestMapping("/wx")
@RestController
public class WeiXinController {
    String appid="公众号id";
    String AppSecret="公众号密钥";
    String originUrl="登录完成后进入的页面";

    @GetMapping("getcode")
    public void getCode(HttpServletResponse response ) throws IOException {
            String cooke="https://open.weixin.qq.com/connect/oauth2/authorize?redirect_uri="+
                originUrl+
                "&appid="+appid+
                "&secret="+AppSecret+
                "&response_type=code" +
                "&scope=snsapi_userinfo" +
                "&state=STATE" +
                "&connect_redirect=1#wechat_redirect";
        //重定向，重定向后就可以看到微信公众号调起登录的选项款，同时微信授权登录后会把code追加到我们重定向地址的后面
        response.sendRedirect(cooke);
    }

	//前端获得code调用请求并把code传到我们获得openid的请求中
    @RequestMapping("/getOpenid")
    public WxInfo  getOpenid(String code) throws IOException {
        WxInfo wxinfo = null;
        //创建请求
        HttpGet Url = new HttpGet("https://api.weixin.qq.com/sns/jscode2session?appid=" +appid + "&secret=" + AppSecret+ "&js_code=" + code + "&grant_type=authorization_code");

        BufferedReader result = getClient(Url); //向微信请求，返回的数据中就有openid信息
        String line="";
        while ((line=result.readLine())!=null){
            wxinfo = JSON.parseObject(line, WxInfo.class);//解析出来的数据时json,我们使用fastjson把数据转换为对象
        }
        return wxinfo;
    }

    //把流转变为IO
    public BufferedReader getClient(HttpGet url){
        CloseableHttpClient httpClient = HttpClientBuilder.create().build();
        try {
            CloseableHttpResponse response = httpClient.execute(url);
            HttpEntity enity = response.getEntity();
            InputStream content = enity.getContent();
            return new BufferedReader(new InputStreamReader(content));//解析url中的数据，就是把它转发为IO流
        } catch (IOException e) {
            e.printStackTrace();
            System.out.println("链接错误，请检查网址");
            return null;
        }
    }
}

7.实体类

@Data
@EqualsAndHashCode(callSuper = false)
@Accessors(chain = true)
public class WxInfo {
    private  String APP_ID;//小程序id
    private  String APP_SECRET;//小程序密钥
    private String session_key;//seesion
    private String openid;//用户openid
}

8.uniapp中获得code

onLoad() {
  let code = this.getQueryString('code')//获得地址中参数
  this.openid(code)
},	
methods: {
	getQueryString(name)  {
			    const reg = new RegExp('(^|&)' + name + '=([^&]*)(&|$)', 'i');
			    const search = window.location.search.split('?')[1] || '';
			    const r = search.match(reg) || [];
			    return r[2];  
			   	}
    openid(codes){  
        let data={  
            code:codes
        }
         uni.request({
            url: '根据code获得openid的接口地址', //仅为示例，并非真实接口地址。
            data: {
                code: codes
            },
            success: function(res) {
                console.log(res.data);
            }
        });
	}
}