在使用OAuth 2.0中的Authorization Code Grant进行登录时，客户端请求通常包含以下参数：
response_type: 必须设置为code。client_id: 应用ID，用于识别客户端。redirect_uri: 用户同意授权后，认证服务器将用户导向这个URI。scope: 请求的权限范围。state: 用于防止CSRF，认证服务器会返回同样的state值。
以下是一个简化的HTTP请求示例：
GET /authorize?response_type=code&client_id=s6BhdRkqt3&state=xyz &redirect_uri=https%3A%2F%2Fclient%2Eexample%2Ecom%2Fcb HTTP/1.1Host: server.example.com
GET /authorize?response_type=code&client_id=s6BhdRkqt3&state=xyz &redirect_uri=https%3A%2F%2Fclient%2Eexample%2Ecom%2Fcb HTTP/1.1Host: server.example.com用户登录并授权后，认证服务器将用户导向redirect_uri并附上授权码：
GET /cb?code=SplxlOBeZQQYbYS6WxSbIA &state=xyz HTTP/1.1Host: client.example.com
GET /cb?code=SplxlOBeZQQYbYS6WxSbIA &state=xyz HTTP/1.1Host: client.example.com客户端使用授权码向认证服务器申请访问令牌：
POST /token HTTP/1.1Host: server.example.comContent-Type: application/x-www-form-urlencoded code=SplxlOBeZQQYbYS6WxSbIA &grant_type=authorization_code &redirect_uri=https%3A%2F%2Fclient%2Eexample%2Ecom%2Fcb &client_id=s6BhdRkqt3 &client_secret=cfde63e633d22a7410ae6c1edaee239c
POST /token HTTP/1.1Host: server.example.comContent-Type: application/x-www-form-urlencoded code=SplxlOBeZQQYbYS6WxSbIA &grant_type=authorization_code &redirect_uri=https%3A%2F%2Fclient%2Eexample%2Ecom%2Fcb &client_id=s6BhdRkqt3 &client_secret=cfde63e633d22a7410ae6c1edaee239c认证服务器验证后，返回访问令牌：
HTTP/1.1 200 OKContent-Type: application/jsonCache-Control: no-storePragma: no-cache { "access_token":"2YotnFZFEjr1zCsicMWpAA", "token_type":"example", "expires_in":3600, "refresh_token":"tGzv3JOkF0XG5Qx2TlKWIA", "example_parameter":"example_value"}
HTTP/1.1 200 OKContent-Type: application/jsonCache-Control: no-storePragma: no-cache { "access_token":"2YotnFZFEjr1zCsicMWpAA", "token_type":"example", "expires_in":3600, "refresh_token":"tGzv3JOkF0XG5Qx2TlKWIA", "example_parameter":"example_value"}以上是使用OAuth 2.0进行授权码流程的简化示例。实际应用中，还需要处理如错误处理、令牌刷新等细节。
