如何在Java前端和后端使用Google Sign

在我的应用程序中，我只想得到用户的Gmail。我不使用任何谷歌服务。我想为Java前端添加Google登录，并在Java后端验证用户

我在看文件

通过在浏览器中打开以下链接，我可以获得代码

（获取）请求：

https://accounts.google.com/o/oauth2/v2/auth/oauthchooseaccount?
response_type=code&
scope=openid&
redirect_uri=http://localhost:3000/auth/&
client_id=113291176157....

{
  code: '4/0AfDhmrjDTOo7zOrXxm98E...',
  scope: 'openid',
  authuser: '0',
  prompt: 'none'
}

https://oauth2.googleapis.com/token

{
  "code": "4/0AfDhmrjDTOo7zOrXxm98E...",
  "client_id": "113291176157-aibhsqjf655ve...",
  "client_secret": "lLjenLdeaJnd...",
  "redirect_uri": "http://localhost:3000/auth",
  "grant_type": "authorization_code"
}

{
  "error": "redirect_uri_mismatch",
  "error_description": "Bad Request"
}

/auth端点获取以下内容：

https://accounts.google.com/o/oauth2/v2/auth/oauthchooseaccount?
response_type=code&
scope=openid&
redirect_uri=http://localhost:3000/auth/&
client_id=113291176157....

{
  code: '4/0AfDhmrjDTOo7zOrXxm98E...',
  scope: 'openid',
  authuser: '0',
  prompt: 'none'
}

https://oauth2.googleapis.com/token

{
  "code": "4/0AfDhmrjDTOo7zOrXxm98E...",
  "client_id": "113291176157-aibhsqjf655ve...",
  "client_secret": "lLjenLdeaJnd...",
  "redirect_uri": "http://localhost:3000/auth",
  "grant_type": "authorization_code"
}

{
  "error": "redirect_uri_mismatch",
  "error_description": "Bad Request"
}

现在要获取用户详细信息

（POST）请求：

https://accounts.google.com/o/oauth2/v2/auth/oauthchooseaccount?
response_type=code&
scope=openid&
redirect_uri=http://localhost:3000/auth/&
client_id=113291176157....

{
  code: '4/0AfDhmrjDTOo7zOrXxm98E...',
  scope: 'openid',
  authuser: '0',
  prompt: 'none'
}

https://oauth2.googleapis.com/token

{
  "code": "4/0AfDhmrjDTOo7zOrXxm98E...",
  "client_id": "113291176157-aibhsqjf655ve...",
  "client_secret": "lLjenLdeaJnd...",
  "redirect_uri": "http://localhost:3000/auth",
  "grant_type": "authorization_code"
}

{
  "error": "redirect_uri_mismatch",
  "error_description": "Bad Request"
}

但我得到了以下回应：

https://accounts.google.com/o/oauth2/v2/auth/oauthchooseaccount?
response_type=code&
scope=openid&
redirect_uri=http://localhost:3000/auth/&
client_id=113291176157....

{
  code: '4/0AfDhmrjDTOo7zOrXxm98E...',
  scope: 'openid',
  authuser: '0',
  prompt: 'none'
}

https://oauth2.googleapis.com/token

{
  "code": "4/0AfDhmrjDTOo7zOrXxm98E...",
  "client_id": "113291176157-aibhsqjf655ve...",
  "client_secret": "lLjenLdeaJnd...",
  "redirect_uri": "http://localhost:3000/auth",
  "grant_type": "authorization_code"
}

{
  "error": "redirect_uri_mismatch",
  "error_description": "Bad Request"
}

我已将重定向URL添加到凭据：

现在，我希望从Java前端打开一个浏览器窗口，让用户登录Google。我将接收

code

值，它将获得

id\u令牌

并验证用户

我见过一些javascript示例，它们直接获得

id\u标记

所以我有很多问题


为什么我需要先获取
code
，然后再请求
id\u令牌
为什么我得到
重定向\u uri\u不匹配
错误
授权码交换请求如下所示

URL:
https://oauth2.googleapis.com/token

POST /token HTTP/1.1
Host: oauth2.googleapis.com
Content-Type: application/x-www-form-urlencoded

code=4/P7q7W91a-oMsCeLvIaQm6bTrgtp7&
client_id=your_client_id&
client_secret=your_client_secret&
redirect_uri=https%3A//oauth2.example.com/code&
grant_type=authorization_code

请求应该是
POST
，数据应该作为
urlencoded
数据发送，而不是在请求正文中

更多信息
您是否碰巧看到了答案。我希望它对你有用。