Pseudow Posts - Answer Overflow

Pseudow

•Created by Pseudow on 5/6/2025 in #java-help

Spring Redis

Hi, I am currently using Spring Boot with Redis and I am using the Caching annotations. Do you know why the first time I hit the endpoint Spring will still make a call to my db even though the data is already in my Redis? After that it will take data from Redis.

8 replies

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•Created by Pseudow on 8/10/2024 in #java-help

Kotlin coroutine

Hi do you know how do I proceed to have my coroutines run on different threads? I have tried this to speed up:

val threadPoolExecutor: ExecutorService = Executors.newFixedThreadPool(3)
val coroutineDispatcher: CoroutineDispatcher = this.threadPoolExecutor.asCoroutineDispatcher()

withContext(coroutineDispatcher) {
    dependencies.forEach { dependency ->
        val resolver = resolvers.first { resolver -> resolver.accept(dependency) }

        launch { resolver.resolve(dependency) }
    }
}

val threadPoolExecutor: ExecutorService = Executors.newFixedThreadPool(3)
val coroutineDispatcher: CoroutineDispatcher = this.threadPoolExecutor.asCoroutineDispatcher()

withContext(coroutineDispatcher) {
    dependencies.forEach { dependency ->
        val resolver = resolvers.first { resolver -> resolver.accept(dependency) }

        launch { resolver.resolve(dependency) }
    }
}

but it tourned out it was less fast than concurrent only?

6 replies

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•Created by Pseudow on 4/21/2024 in #java-help

Protobuf Proto source set not added

4 replies

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•Created by Pseudow on 4/20/2024 in #java-help

hasAuthority Spring doesn't work

Hi I have replaced the default permission evaluator but now it just makes the hasAuthority not working (I am using the same example as the ones on google but it doesn't work with me)

@Bean
fun expressionHandler(@Autowired permissionEvaluator: CustomPermissionEvaluator,
                      @Autowired roleHierarchy: RoleHierarchy): MethodSecurityExpressionHandler {
    val handler = DefaultMethodSecurityExpressionHandler()
    handler.setPermissionEvaluator(permissionEvaluator)
    handler.setRoleHierarchy(roleHierarchy)

    return handler
}

@Bean
fun expressionHandler(@Autowired permissionEvaluator: CustomPermissionEvaluator,
                      @Autowired roleHierarchy: RoleHierarchy): MethodSecurityExpressionHandler {
    val handler = DefaultMethodSecurityExpressionHandler()
    handler.setPermissionEvaluator(permissionEvaluator)
    handler.setRoleHierarchy(roleHierarchy)

    return handler
}

Here is my error

Property or field 'hasAuthority' cannot be found on object of type 'org.springframework.security.access.expression.method.MethodSecurityExpressionRoot' - maybe not public or not valid?

6 replies

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•Created by Pseudow on 4/19/2024 in #java-help

Ktor Login Bearer Token

How can I make a login step using credentials to retrieve my bearer tokens with Ktor because in the inialization of my client I can't access the client itself?

5 replies

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•Created by Pseudow on 4/17/2024 in #java-help

Spring admin authorization

Is it possible to give all authorization to administrators without having to create all existing permissions to add them to the role?

4 replies

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•Created by Pseudow on 4/14/2024 in #java-help

Spring Context Holder

How spring context holder works? Does the current user is stored in the client or something like this? Because basically if I made an API should I rely on a JWT or just the context holder is enough?

4 replies

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•Created by Pseudow on 3/30/2024 in #java-help

Spring Password Encoder Argon2

Hi I just went into the spring argon2 password encoder and I saw this:

public String encode(CharSequence rawPassword) {
        byte[] salt = this.saltGenerator.generateKey();
        byte[] hash = new byte[this.hashLength];
        Argon2Parameters params = (new Argon2Parameters.Builder(2)).withSalt(salt).withParallelism(this.parallelism).withMemoryAsKB(this.memory).withIterations(this.iterations).build();
        Argon2BytesGenerator generator = new Argon2BytesGenerator();
        generator.init(params);
        generator.generateBytes(rawPassword.toString().toCharArray(), hash);
        return Argon2EncodingUtils.encode(hash, params);
    }

public String encode(CharSequence rawPassword) {
        byte[] salt = this.saltGenerator.generateKey();
        byte[] hash = new byte[this.hashLength];
        Argon2Parameters params = (new Argon2Parameters.Builder(2)).withSalt(salt).withParallelism(this.parallelism).withMemoryAsKB(this.memory).withIterations(this.iterations).build();
        Argon2BytesGenerator generator = new Argon2BytesGenerator();
        generator.init(params);
        generator.generateBytes(rawPassword.toString().toCharArray(), hash);
        return Argon2EncodingUtils.encode(hash, params);
    }

spring encode my password with all the params to decode it, so should I rewrite my own password encoder or anything like this?

4 replies

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•Created by Pseudow on 3/9/2024 in #java-help

Kotlin Serialization Spring Integration

Hi I encountered a problem, I am currently trying to create unit test in order to test my API responses but I just found out that even by specifying that I want spring to use kotlin serialization to serialize controller responses it doesn't not work. Here is my configuration:

@Configuration
class WebSerializationConfiguration: WebMvcConfigurer {
    private val converter = KotlinSerializationJsonHttpMessageConverter(DEFAULT_JSON)

    override fun configureMessageConverters(converters: MutableList<HttpMessageConverter<*>>) {
        converters.add(this.converter)
    }
}

@Configuration
class WebSerializationConfiguration: WebMvcConfigurer {
    private val converter = KotlinSerializationJsonHttpMessageConverter(DEFAULT_JSON)

    override fun configureMessageConverters(converters: MutableList<HttpMessageConverter<*>>) {
        converters.add(this.converter)
    }
}

I even tried to just remove the json from my dependency:

implementation("org.springframework.boot:spring-boot-starter-web") {
        exclude("org.springframework.boot:spring-boot-starter-json")
    }

implementation("org.springframework.boot:spring-boot-starter-web") {
        exclude("org.springframework.boot:spring-boot-starter-json")
    }

But it doesn't work and I get a weird serializable

5 replies

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•Created by Pseudow on 3/9/2024 in #java-help

Kotlin Serialization

Hi guys do you know why do I get an error from my kotlin code?

@Serializable(with = DefinitionExceptionSerializer::class)
sealed class DefinitionException(
    val id: String,
    override val message: String
): Exception(message)

@Serializable
class InvitationAlreadySentException(val expire: Instant): DefinitionException(
    "${Invitation.ENTITY_NAME}-already-sent",
    "Invite already pending, you will be able to try again in ${expire.epochSecond - Instant.now().epochSecond}"
)

@Serializable(with = DefinitionExceptionSerializer::class)
sealed class DefinitionException(
    val id: String,
    override val message: String
): Exception(message)

@Serializable
class InvitationAlreadySentException(val expire: Instant): DefinitionException(
    "${Invitation.ENTITY_NAME}-already-sent",
    "Invite already pending, you will be able to try again in ${expire.epochSecond - Instant.now().epochSecond}"
)

I get this error from the class InvitationAlreadySentException Impossible to make this class serializable because its parent is not serializable and does not have exactly one constructor without parameters

4 replies

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•Created by Pseudow on 3/1/2024 in #java-help

Spring Security Mock MVC Test

Hi I am trying to use Spring to test my controller but here is the definition of my test class:

@SpringBootTest(
    webEnvironment = SpringBootTest.WebEnvironment.MOCK,
    classes = [ProfileController::class]
)
@AutoConfigureMockMvc(addFilters = false)
@TestInstance(TestInstance.Lifecycle.PER_CLASS)
@TestMethodOrder(MethodOrderer.OrderAnnotation::class)
@ActiveProfiles("test", REST_API_PROFILE_NAME)
@DisplayName("Profile Controller Test")
class ProfileControllerTest

@SpringBootTest(
    webEnvironment = SpringBootTest.WebEnvironment.MOCK,
    classes = [ProfileController::class]
)
@AutoConfigureMockMvc(addFilters = false)
@TestInstance(TestInstance.Lifecycle.PER_CLASS)
@TestMethodOrder(MethodOrderer.OrderAnnotation::class)
@ActiveProfiles("test", REST_API_PROFILE_NAME)
@DisplayName("Profile Controller Test")
class ProfileControllerTest

In the SpringBootTest#classes method I specified my controller but when I run it, Spring doesn't automatically create all needed beans for example ProfileService or ProfileDao

4 replies

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•Created by Pseudow on 2/22/2024 in #java-help

Snowflake x Spring

Hi I am planning on using Snowflake algorithm to generate ids, but I wanted to know more about it so basically there are three ways of customizing it with the timestamp bits, the generator bits and sequence bits. The addition of all those bits have to equal 63 bits but what is the best way to make it work with my spring application? Each backend instance would have an unique generator id? Because if for example there are two backends that receives one request at the same time to send a message for example with the same generator id it could potentially create two same ids?

7 replies

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•Created by Pseudow on 2/3/2024 in #java-help

Spring Security

Hi is it possible to modify how spring security deals with passwords? Actually I would like my password to stay only in my database and never retrieve it just checking if for the account the password matches. But everywhere including in UserDetails I have to give access to the password to Spring.

45 replies

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