spring oauth2 获取token

您可以使用Spring Security OAuth2来获取token。以下是基本的步骤：

1. 首先，您需要添加所需的依赖项。在您的项目的pom.xml文件中添加以下依赖项：

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-oauth2-client</artifactId>
</dependency>

2. 在application.properties或application.yml文件中配置OAuth2客户端的信息。例如：

spring:
  security:
    oauth2:
      client:
        registration:
          my-client-id:
            client-id: your-client-id
            client-secret: your-client-secret
            provider: your-authorization-server

请替换`my-client-id`，`your-client-id`，`your-client-secret`和`your-authorization-server`为您的实际值。

3. 在您的代码中，您可以使用`RestTemplate`或`WebClient`来发送请求并获取token。以下是使用`RestTemplate`的示例代码：

import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpMethod;
import org.springframework.http.MediaType;
import org.springframework.http.RequestEntity;
import org.springframework.http.ResponseEntity;
import org.springframework.security.oauth2.client.OAuth2AuthorizedClientManager;
import org.springframework.security.oauth2.client.OAuth2AuthorizedClientProvider;
import org.springframework.security.oauth2.client.OAuth2AuthorizedClientProviderBuilder;
import org.springframework.security.oauth2.client.registration.ClientRegistration;
import org.springframework.security.oauth2.client.registration.ClientRegistrationRepository;
import org.springframework.security.oauth2.core.AuthorizationGrantType;
import org.springframework.security.oauth2.core.OAuth2AccessToken;
import org.springframework.security.oauth2.core.endpoint.OAuth2AccessTokenResponse;
import org.springframework.security.oauth2.core.endpoint.OAuth2AuthorizationCodeGrantRequest;
import org.springframework.security.oauth2.core.endpoint.OAuth2AuthorizationRequest;
import org.springframework.security.oauth2.core.endpoint.OAuth2AuthorizationResponse;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;

import java.net.URI;
import java.util.Collections;

@RestController
public class OAuth2Controller {

    private final ClientRegistrationRepository clientRegistrationRepository;
    private final OAuth2AuthorizedClientManager authorizedClientManager;

    public OAuth2Controller(ClientRegistrationRepository clientRegistrationRepository,
                            OAuth2AuthorizedClientManager authorizedClientManager) {
        this.clientRegistrationRepository = clientRegistrationRepository;
        this.authorizedClientManager = authorizedClientManager;
    }

    @GetMapping("/oauth2/token")
    public String getToken() {
        // 获取ClientRegistration
        ClientRegistration clientRegistration = clientRegistrationRepository.findByRegistrationId("my-client-id");

        // 构建OAuth2AuthorizationRequest
        OAuth2AuthorizationRequest authorizationRequest = OAuth2AuthorizationRequest.authorizationCode()
                .clientId(clientRegistration.getClientId())
                .authorizationUri(clientRegistration.getProviderDetails().getAuthorizationUri())
                .redirectUri(URI.create("http://localhost:8080/oauth2/callback"))
                .scopes(clientRegistration.getScopes())
                .state("state")
                .build();

        // 构建OAuth2AuthorizationResponse
        OAuth2AuthorizationResponse authorizationResponse = OAuth2AuthorizationResponse.success("authorization-code")
                .redirectUri("http://localhost:8080/oauth2/callback")
                .state("state")
                .build();

        // 构建OAuth2AuthorizationCodeGrantRequest
        OAuth2AuthorizationCodeGrantRequest authorizationCodeGrantRequest = new OAuth2AuthorizationCodeGrantRequest(
                clientRegistration, authorizationRequest, authorizationResponse);

        // 构建OAuth2AuthorizedClientProvider
        OAuth2AuthorizedClientProvider authorizedClientProvider = OAuth2AuthorizedClientProviderBuilder.builder()
                .authorizationCode()
                .build();

        // 获取OAuth2AuthorizedClient
        OAuth2AuthorizedClient authorizedClient = authorizedClientManager.authorize(authorizationCodeGrantRequest);

        // 构建请求头
        HttpHeaders headers = new HttpHeaders();
        headers.setAccept(Collections.singletonList(MediaType.APPLICATION_JSON));
        headers.setBearerAuth(authorizedClient.getAccessToken().getTokenValue());

        // 发送请求并获取响应
        RequestEntity<Void> requestEntity = new RequestEntity<>(headers, HttpMethod.GET, URI.create("http://api.example.com/resource"));
        ResponseEntity<String> responseEntity = new RestTemplate().exchange(requestEntity, String.class);

        return responseEntity.getBody();
    }
}

请确保替换`my-client-id`和`http://localhost:8080/oauth2/callback`为实际值。在这个例子中，我们模拟了一个授权码授权流程来获取token，并使用token发送请求并获取资源的响应。

这只是一个简单的示例，实际的实现可能会有所不同，具体取决于您的认证服务器和需求。您可以根据您的情况进行调整和扩展。