现在第三方登录的例子数见不鲜。其实在这种示例当中，oauth2.0是使用比较多的一种授权登录的标准。oauth2.0也是从oauth1.0升级过来的。那么关于oauth2.0相关的概念及其原理，大家可以参考这篇文章，这篇文章中会有更详细的解释，下来我们直接进入正题。

1.1、gradle依赖

      compile('org.springframework.cloud:spring-cloud-starter-oauth2')
      compile('org.springframework.cloud:spring-cloud-starter-security')

在这里我直接引入的是spring-cloud的依赖项，这种依赖的jar包更全面一些，这里面的核心基础还是spring-security。这里SpringBoot的版本为2.0.6.REALEASE

1.2、@EnableAuthorizationServer

在这里我着重强调一下这个注解：@EnableAuthorizationServer，这个注解源代码如下：

    @Target(ElementType.TYPE)
    @Retention(RetentionPolicy.RUNTIME)
    @Documented
    @Import({AuthorizationServerEndpointsConfiguration.class, AuthorizationServerSecurityConfiguration.class})
    public @interface EnableAuthorizationServer {
    
    }

这个注解主要是导入两个配置类，分别是：

• AuthorizationServerEndpointsConfiguration，这个配置类主要配置授权端点，获取token的端点。大家就把对应的端点想象成controller即可，在这个controller下开放了若干个@RequestMapping,比如常见的有：/oauth/authorize(授权路径)，/oauth/token(获取token)等
• AuthorizationServerSecurityConfiguration，主要是做spring-security的安全配置，我们可以看一下相关代码：

      public class AuthorizationServerSecurityConfiguration extends WebSecurityConfigurerAdapter {
         @Autowired
          private List<AuthorizationServerConfigurer> configurers = Collections.emptyList();
      
          @Autowired
          private ClientDetailsService clientDetailsService;
      
          @Autowired
          private AuthorizationServerEndpointsConfiguration endpoints;
      
          @Autowired
          public void configure(ClientDetailsServiceConfigurer clientDetails) throws Exception {
              for (AuthorizationServerConfigurer configurer : configurers) {
                  configurer.configure(clientDetails);
              }
          }
      
          @Override
          protected void configure(AuthenticationManagerBuilder auth) throws Exception {
              // Over-riding to make sure this.disableLocalConfigureAuthenticationBldr = false
              // This will ensure that when this configurer builds the AuthenticationManager it will not attempt
              // to find another 'Global' AuthenticationManager in the ApplicationContext (if available),
              // and set that as the parent of this 'Local' AuthenticationManager.
              // This AuthenticationManager should only be wired up with an AuthenticationProvider
              // composed of the ClientDetailsService (wired in this configuration) for authenticating 'clients' only.
          }
      
          @Override
          protected void configure(HttpSecurity http) throws Exception {
              //....省略部分代码
              String tokenEndpointPath = handlerMapping.getServletPath("/oauth/token");
              String tokenKeyPath = handlerMapping.getServletPath("/oauth/token_key");
              String checkTokenPath = handlerMapping.getServletPath("/oauth/check_token");
              if (!endpoints.getEndpointsConfigurer().isUserDetailsServiceOverride()) {
                  UserDetailsService userDetailsService = http.getSharedObject(UserDetailsService.class);
                  endpoints.getEndpointsConfigurer().userDetailsService(userDetailsService);
              }
              // @formatter:off
              //上述节点的请求需要授权验证
              http
                  .authorizeRequests()
                      .antMatchers(tokenEndpointPath).fullyAuthenticated()
                      .antMatchers(tokenKeyPath).access(configurer.getTokenKeyAccess())
                      .antMatchers(checkTokenPath).access(configurer.getCheckTokenAccess())
              .and()
                  .requestMatchers()
                      .antMatchers(tokenEndpointPath, tokenKeyPath, checkTokenPath)
              .and()
                  .sessionManagement().sessionCreationPolicy(SessionCreationPolicy.NEVER);
              // @formatter:on
              http.setSharedObject(ClientDetailsService.class, clientDetailsService);
          }
      
          protected void configure(AuthorizationServerSecurityConfigurer oauthServer) throws Exception {
              for (AuthorizationServerConfigurer configurer : configurers) {
                  configurer.configure(oauthServer);
              }
          }
      }

1.2.1、AuthorizationServerConfigurer

这个接口是认证授权配置的核心接口，不过既然是SpringBoot我们就先来看看它怎么帮我们装配的，我们可以在org.springframework.boot.autoconfigure.security.oauth2.authserver这个包下面找到对应配置的Bean:

    @Configuration
    @ConditionalOnClass(EnableAuthorizationServer.class)
    @ConditionalOnMissingBean(AuthorizationServerConfigurer.class)
    @ConditionalOnBean(AuthorizationServerEndpointsConfiguration.class)
    @EnableConfigurationProperties(AuthorizationServerProperties.class)
    public class OAuth2AuthorizationServerConfiguration
            extends AuthorizationServerConfigurerAdapter {
        //....
        @Override
        public void configure(ClientDetailsServiceConfigurer clients) throws Exception {
            //默认基于内存创建ClientDetails
            ClientDetailsServiceBuilder<InMemoryClientDetailsServiceBuilder>.ClientBuilder builder = clients
                    .inMemory().withClient(this.details.getClientId());
            builder.secret(this.details.getClientSecret())
                    .resourceIds(this.details.getResourceIds().toArray(new String[0]))
                    .authorizedGrantTypes(
                            this.details.getAuthorizedGrantTypes().toArray(new String[0]))
                    .authorities(
                            AuthorityUtils.authorityListToSet(this.details.getAuthorities())
                                    .toArray(new String[0]))
                    .scopes(this.details.getScope().toArray(new String[0]));
    
            if (this.details.getAutoApproveScopes() != null) {
                builder.autoApprove(
                        this.details.getAutoApproveScopes().toArray(new String[0]));
            }
            if (this.details.getAccessTokenValiditySeconds() != null) {
                builder.accessTokenValiditySeconds(
                        this.details.getAccessTokenValiditySeconds());
            }
            if (this.details.getRefreshTokenValiditySeconds() != null) {
                builder.refreshTokenValiditySeconds(
                        this.details.getRefreshTokenValiditySeconds());
            }
            if (this.details.getRegisteredRedirectUri() != null) {
                builder.redirectUris(
                        this.details.getRegisteredRedirectUri().toArray(new String[0]));
            }
        }
    
        @Override
        public void configure(AuthorizationServerEndpointsConfigurer endpoints)
                throws Exception {
            if (this.tokenConverter != null) {
                endpoints.accessTokenConverter(this.tokenConverter);
            }
            if (this.tokenStore != null) {
                endpoints.tokenStore(this.tokenStore);
            }
            if (this.details.getAuthorizedGrantTypes().contains("password")) {
                endpoints.authenticationManager(this.authenticationManager);
            }
        }
    
        @Override
        public void configure(AuthorizationServerSecurityConfigurer security)
                throws Exception {
            security.passwordEncoder(NoOpPasswordEncoder.getInstance());
            if (this.properties.getCheckTokenAccess() != null) {
                security.checkTokenAccess(this.properties.getCheckTokenAccess());
            }
            if (this.properties.getTokenKeyAccess() != null) {
                security.tokenKeyAccess(this.properties.getTokenKeyAccess());
            }
            if (this.properties.getRealm() != null) {
                security.realm(this.properties.getRealm());
            }
        }
        
        
        
        @Configuration
        @ConditionalOnMissingBean(BaseClientDetails.class)
        protected static class BaseClientDetailsConfiguration {
    
            private final OAuth2ClientProperties client;
    
            protected BaseClientDetailsConfiguration(OAuth2ClientProperties client) {
                this.client = client;
            }
    
            /**
                由此可知它会寻找security.oauth2.client的配置
            */
            @Bean
            @ConfigurationProperties(prefix = "security.oauth2.client")
            public BaseClientDetails oauth2ClientDetails() {
                BaseClientDetails details = new BaseClientDetails();
                if (this.client.getClientId() == null) {
                    this.client.setClientId(UUID.randomUUID().toString());
                }
                details.setClientId(this.client.getClientId());
                details.setClientSecret(this.client.getClientSecret());
                details.setAuthorizedGrantTypes(Arrays.asList("authorization_code",
                        "password", "client_credentials", "implicit", "refresh_token"));
                details.setAuthorities(
                        AuthorityUtils.commaSeparatedStringToAuthorityList("ROLE_USER"));
                details.setRegisteredRedirectUri(Collections.<String>emptySet());
                return details;
            }
    
        }
    
    
    }

如果没有用spring-boot的用户，可以也可以参考上述的配置方法，自行配置

1.3、application.yml的配置

根据上述代码我们可以知道，springboot通过外部化配置的security.oauth2.client的前缀来配置客户端。那么因此我们不妨在外部化配置文件里做如下配置：

    server:
      port: 8080
    security:
      oauth2:
        client:
          client-id: root
          client-secret: root
          scope:
            - email
            - username
            - face
    spring:
      security:
        user:
          name: root
          password: root
          roles: ADMIN

这里先做最基本的配置，配置client-id，client-secret，scope。特别注意oauth2.0一定要先经过springsecurity的auth认证，因此需要在这里配置一个内存用户名与密码为root与root

1.4、配置资源服务器

通过资源服务器来保护我们指定的资源，必须在获取授权认证的时候才能访问。在SpringBoot当中，我们可以通过@EnableResourceServer注解来开启此功能。该注解定义如下：

    @Target(ElementType.TYPE)
    @Retention(RetentionPolicy.RUNTIME)
    @Documented
    @Import(ResourceServerConfiguration.class)
    public @interface EnableResourceServer {
    
    }

我们可以看到这个注解导入了默认的资源配置信息：ResourceServerConfiguration，它的源代码如下：

    @Configuration
    public class ResourceServerConfiguration extends WebSecurityConfigurerAdapter implements Ordered {
        //....
            @Override
        protected void configure(HttpSecurity http) throws Exception {
            ResourceServerSecurityConfigurer resources = new ResourceServerSecurityConfigurer();
            ResourceServerTokenServices services = resolveTokenServices();
            if (services != null) {
                resources.tokenServices(services);
            }
            else {
                if (tokenStore != null) {
                    resources.tokenStore(tokenStore);
                }
                else if (endpoints != null) {
                    resources.tokenStore(endpoints.getEndpointsConfigurer().getTokenStore());
                }
            }
            if (eventPublisher != null) {
                resources.eventPublisher(eventPublisher);
            }
            //配置资源
            for (ResourceServerConfigurer configurer : configurers) {
                configurer.configure(resources);
            }
            // @formatter:off
            http.authenticationProvider(new AnonymousAuthenticationProvider("default"))
            // N.B. exceptionHandling is duplicated in resources.configure() so that
            // it works
            .exceptionHandling()
                    .accessDeniedHandler(resources.getAccessDeniedHandler()).and()
                    .sessionManagement()
                    .sessionCreationPolicy(SessionCreationPolicy.STATELESS).and()
                    .csrf().disable();
            // @formatter:on
            http.apply(resources);
            if (endpoints != null) {
                // Assume we are in an Authorization Server
                http.requestMatcher(new NotOAuthRequestMatcher(endpoints.oauth2EndpointHandlerMapping()));
            }
            for (ResourceServerConfigurer configurer : configurers) {
                // Delegates can add authorizeRequests() here
                configurer.configure(http);
            }
            //如果没有任何配置资源，则所有请求保护
            if (configurers.isEmpty()) {
                // Add anyRequest() last as a fall back. Spring Security would
                // replace an existing anyRequest() matcher with this one, so to
                // avoid that we only add it if the user hasn't configured anything.
                http.authorizeRequests().anyRequest().authenticated();
            }
        }
        //....
        
    }

在这里主要是配置资源服务器的配置，我们可以得到如下几点信息：

• 资源配置的核心ResourceServerConfigurer，在这里如果没有任何配置，则所有请求都要进行token认证
• TokenStore 主要定义了对token的增删改查操作，用于持久化token
• ResourceServerTokenServices 资源服务的service(服务层)，这里主要还是根据token来拿到OAuth2Authentication与OAuth2AccessToken

1.5、完整示例

1.5.1、资源认证配置

    @Configuration
    @EnableResourceServer
    public class ResourceConfigure extends ResourceServerConfigurerAdapter {
    
        @Override
        public void configure(HttpSecurity http) throws Exception {
            http.csrf().disable().sessionManagement().sessionCreationPolicy(SessionCreationPolicy.IF_REQUIRED)
                    .and().authorizeRequests().antMatchers("/free/**").permitAll().and()
                    .authorizeRequests().anyRequest().authenticated()
                    .and().formLogin().permitAll();//必须认证过后才可以访问
        }
    }
    

在这里如果以/free/**请求路径的，都允许直接访问。否则，都必须携带access_token才能访问。

1.5.2 、授权认证配置

    @Configuration
    public class WebSecurityConfig extends WebSecurityConfigurerAdapter {
    
        @Override
        protected void configure(HttpSecurity http) throws Exception {
            http.csrf().disable().requestMatchers().anyRequest().and().authorizeRequests()
                    .antMatchers("/oauth/*").authenticated().and().formLogin().permitAll();
        }
    }

根据上文所述，AuthorizationServerEndpoint与TokenEndpoint会开放/oauth/authorize与/oauth/token端点，因此我们必须保证访问端点进行授权认证前，通过springsecurity的用户认证，因此在这里配置了/oauth/*

1.5.3、启动类

    @SpringBootApplication
    @EnableAuthorizationServer
    @Controller
    public class AuthorizationServer {
        
       
       @GetMapping("/order")
        public ResponseEntity<String> order() {
            ResponseEntity<String> responseEntity = new ResponseEntity("order", HttpStatus.OK);
            return responseEntity;
        }
    
        @GetMapping("/free/test")
        public ResponseEntity<String> test() {
            ResponseEntity<String> responseEntity = new ResponseEntity("free", HttpStatus.OK);
            return responseEntity;
        }
        
         public static void main(String[] args) {
            SpringApplication.run(AuthorizationServer.class, args);
        }
    }

1.5.4、访问请求

首先我们通过postman 访问http://localhost:8080/order会得到如下界面：

此时我们明显可以看到对应的资源需要携带有效的token才可以访问，那么我们此时要在postman的Authorization进行oauth2.0配置认证。截图如下：

在这里点击Get New Access Token 来从认证服务器获取token，点击后配置如下：

`

• scope配置对应application.yml中的配置信息，这里面可以放置用户的属性信息，比如说昵称 头像 电话等等
• State代表状态码，设置一个State标志
• 回调地址这里必须配置，通过这个地址当同意授权后会返回一个认证的code给我们，我们根据这个code请求token
• 认证地址与获取token的地址请填写，相关Endpoint生成的地址

当经过一连串认证后，我们即可拿到token:

当我们获取到最新的token以后，我们即可访问到对应的请求资源：