Question

我正在Android（kotlin）项目中使用Retrofit。

我创建了我的界面：

interface StudentsInterface {
    @GET("foo/bar/{id}")
    suspend fun getStudent(@Path("id") myId: Int)
}

我创建了一个MyClient类，在其中定义了一个通用函数，用于从上述定义的任何接口创建端点服务：

class MyClient() {
    @Inject
    lateinit var  retrofit: Retrofit

    // this is my generic function
    fun <T> createService(interfaceClazz: Class<T>?): T {
        // Compiler error: Type mismatch: inferred type is Class<T>? but Class<T!> was expected
        return retrofit.create(interfaceClazz)
    }
}

这样我可以在另一堂课中

val sService = myClient.createService(StudentsInterface::class.java)
...

但是当我构建项目时，总是会遇到编译器错误：在代码Type mismatch: inferred type is Class<T>? but Class<T!> was expected行中的return retrofit.create(interfaceClazz)

为什么会出现此错误？如何摆脱它？

Answer 1

改造创建需要不可为空的参数。尝试使@Configuration @EnableWebSecurity @EnableGlobalMethodSecurity(prePostEnabled = true) public class WebSecurityConfig extends WebSecurityConfigurerAdapter { @Value("${auth.issuer-uri}") String authIssuerUri; @Override public void configure(HttpSecurity http) throws Exception { http .csrf().disable()//enable later .sessionManagement().sessionCreationPolicy(SessionCreationPolicy.IF_REQUIRED).and() .authorizeRequests( ar -> ar .antMatchers("/register").permitAll() .anyRequest().authenticated()) .oauth2ResourceServer(OAuth2ResourceServerConfigurer::jwt); } // this should be used on authorization @Bean JwtDecoder jwtDecoder() { //tried to replicate what spring does by default by adding one more JwtAudienceValidator List<OAuth2TokenValidator<Jwt>> validators = new ArrayList<>(); validators.add(new JwtTimestampValidator()); validators.add(new JwtIssuerValidator(authIssuerUri)); validators.add(new JwtAudienceValidator()); NimbusJwtDecoder jwtDecoder = (NimbusJwtDecoder) JwtDecoders.fromIssuerLocation(authIssuerUri); jwtDecoder.setJwtValidator(new DelegatingOAuth2TokenValidator<>(validators)); return jwtDecoder; } }不可为空

auth.issuer-uri= from system props

spring.security.oauth2.resourceserver.jwt.issuer-uri=${auth.issuer-uri}

#spring.security.oauth2.client.provider.okta.issuer-uri= ${auth.issuer-uri} tried this also adding relevant spring gradle deps

我用于Retrofit接口创建的通用函数得到编译器错误：推断的类型为Class <T>？但是应该是Class <T！>

1 个答案: