步骤一、在GitHub上设置一个OAuth App

一

二

三

四

举例

保存好secrets

步骤二、前端

1. 设置一个按钮跳转到授权登录页

<a href="https://github.com/login/oauth/authorize?
client_id=b9c6b520a5fe17cad4d4&
redirect_uri=http://localhost:20000/oauth/redirect">GitHub</a>

client_id：GitHub网站接入提供的 APP KEY

redirect_uri：认证后重定向的地址

GitHub授权页面

1. 点击授权

会有一个跳转等待页

网络不稳定可能一直卡在这个页面

F12查看网络，可以看见网站向后端发了一个code码，这个code用来换取token

步骤三、编写后端代码

1. 从配置文件中读取clientId和clientSecret，当然硬编码也行

@Component
@ConfigurationProperties(prefix = "github")
public class GitHubOAuthInfo {private String clientId;private String clientSecret;public GitHubOAuthInfo() {}public GitHubOAuthInfo(String clientId, String clientSecret) {this.clientId = clientId;this.clientSecret = clientSecret;}public String getClientId() {return clientId;}public void setClientId(String clientId) {this.clientId = clientId;}public String getClientSecret() {return clientSecret;}public void setClientSecret(String clientSecret) {this.clientSecret = clientSecret;}
}

1. 核心代码（有一些我自己项目里的代码，注意修改）

    //用来发送请求的工具类，这个网上有很多现成的@AutowiredRestTemplateUtil restTemplateUtil;//用户模块远程调用接口@AutowiredMemberFeignService memberFeignService;//clientId和clientSecret@AutowiredGitHubOAuthInfo gitHubOAuthInfo;@GetMapping("/redirect")public String redirect(String code, HttpSession session) {//拿到code，clientId和clientSecret去获取accessTokenString getAccessTokenUrl = "https://github.com/login/oauth/access_token";HttpHeaders headers = new HttpHeaders();List<MediaType> mediaTypes = new ArrayList<>();//请求头accept设置为：application/jsonmediaTypes.add(MediaType.APPLICATION_JSON);headers.setAccept(mediaTypes);HashMap<String, String> requestBody = new HashMap<>(16);requestBody.put("client_id", gitHubOAuthInfo.getClientId());requestBody.put("client_secret", gitHubOAuthInfo.getClientSecret());requestBody.put("code", code);//请求路径，请求头，请求体，请求响应结果类型，路径参数ResponseEntity<String> responseEntity = restTemplateUtil.post(getAccessTokenUrl, headers, requestBody, String.class, new HashMap<>(16));String accessTokenJson = responseEntity.getBody();ObjectMapper objectMapper = new ObjectMapper();//转换带下划线的属性为驼峰属性objectMapper.setPropertyNamingStrategy(PropertyNamingStrategy.SNAKE_CASE);AccessToken accessToken = null;try {accessToken = objectMapper.readValue(accessTokenJson, AccessToken.class);} catch (JsonProcessingException e) {e.printStackTrace();}//拿令牌去获取信息headers.set("Authorization", "token " + accessToken.getAccessToken());String getUserInfoUrl = "https://api.github.com/user";ResponseEntity<String> response = restTemplateUtil.get(getUserInfoUrl, headers, String.class, new HashMap<>(16));//body：GitHub用户信息String body = response.getBody();GitHubUserInfo gitHubUserInfo = JSON.parseObject(body, GitHubUserInfo.class);gitHubUserInfo.setToken(accessToken.getAccessToken());//知道当前是哪个社交用户//1.当前用户如果是第一次进网站，自动注册进来(为当前社交用户生成一个会员信息账号,以后这个社交账号就对应指定的会员)R login = memberFeignService.login(gitHubUserInfo);if (login.getCode() == 0) {MemberRespVo data = login.getData("data", new TypeReference<MemberRespVo>() {});session.setAttribute(AuthServerConstant.LOGIN_USER, data);return "redirect:http://meiwei.com";} else {return "redirect:http://auth.meiwei.com/login.html";}}

总结流程