@QuerydslPredicate throwing exception

Question

I\'m trying to understand how to use @QuerydslPredicate but my test API fails when it is called:

Servlet.service() for servlet [dispatcherServle         


        

Answer 1

Extending on @cristobalrosa's answer, this might be due to web application not being configured by Spring Boot. For instance my project also had a SwaggerConfig extending WebMvcConfigurationSupport:

@Configuration
@EnableSwagger2
public class SwaggerConfig extends WebMvcConfigurationSupport {
    // Docket bean
    
    @Override
    protected void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("swagger-ui.html").addResourceLocations("classpath:/META-INF/resources/");
    }
}

I removed the inheritance and manual resource handlers, and it works fine now.

Note: In addition to WebMvcConfigurationSupport, things like @EnableWebMvc & WebMvcConfigurer might also lead to Spring Boot's web autoconfiguration not being used.

Sources: Swagger Issue comment

Answer 2

If you comment out the @Configuration on the swagger configuration class it will work. I'm still trying to understand why, I guess that with that annotation the way spring loads the configuration is different and this is causing the issue.

//@Configuration
@EnableSwagger2
public class SwaggerConfiguration extends WebMvcConfigurationSupport

Answer 3

I think your problem lies in your pom.xml. Be sure you are using compatible version of query-dsl. For instance if you use spring-data-jpa 2.0.8, you should use querydsl-* 4.1.4+

<dependency>
    <groupId>org.springframework.data</groupId>
    <artifactId>spring-data-jpa</artifactId>
    <version>2.0.8.RELEASE</version>
</dependency>

<dependency>
    <groupId>com.querydsl</groupId>
    <artifactId>querydsl-*</artifactId>
    <version>4.1.4</version>
</dependency>

you can check in maven repository which version you need

Edit 1 try to add the querydsl-core to your maven:

 <dependency>
        <groupId>com.querydsl</groupId>
        <artifactId>querydsl-core</artifactId>
        <version>4.1.4</version>
 </dependency>

Answer 4

Same error with me.

I just want to share the situation to may give some hints. So look at my config and dependencies and read articles that I linked. try @EnableWebMvc instead of 'WebMvcConfigurationSupport'

Error

java.lang.IllegalStateException: No primary or default constructor found for interface com.querydsl.core.types.Predicate
Caused by: java.lang.NoSuchMethodException: com.querydsl.core.types.Predicate.<init>()
    at java.base/java.lang.Class.getConstructor0(Class.java:3427)
    at java.base/java.lang.Class.getDeclaredConstructor(Class.java:2631)
    at org.springframework.web.method.annotation.ModelAttributeMethodProcessor.createAttribute(ModelAttributeMethodProcessor.java:216)

---

dependencies

    dependencies {
        implementation 'org.springframework.boot:spring-boot-starter-web'
        implementation "org.springframework.data:spring-data-commons"
        implementation "com.querydsl:querydsl-apt:4.3.1"
        implementation "com.querydsl:querydsl-jpa:4.3.1"
    }

Querydsl web support is available in spring-data-commons since 1.11 from https://www.baeldung.com/rest-api-search-querydsl-web-in-spring-data-jpa

Web Mvc Config

In my case, I have to implements WebMvcConfigurer and add @EnableWebMvc instead of WebMvcConfigurationSupport. I don't know why @EnableWebMvc is needed even I had extended WebMvcConfigurationSupport with @Configuration. I just guess WebMvcConfigurationSupport doesn't implements init() of Predicate.

@Configuration
//@EnableSpringDataWebSupport // <-- doesn't necessary for me
@EnableSwagger2
@EnableWebMvc // <-- add
public class SwaggerConfig implements WebMvcConfigurer { //<-- instead of 'WebMvcConfigurationSupport'
   ...
}

QueryDSL web support From Spring document

The feature will be automatically enabled along @EnableSpringDataWebSupport when Querydsl is found on the classpath. https://docs.spring.io/spring-data/jpa/docs/1.9.0.RELEASE/reference/html/#core.web.type-safe

Controller

    @GetMapping
    public List<InputMethodDto.Response> getInputMethodTypeList(
            @QuerydslPredicate(root = InputMethod.class) Predicate predicate) {
        return service.getInputMethodList(predicate);
    }

Repository

public interface InputMethodRepository extends JpaRepository<yourEntity, Long>, QuerydslPredicateExecutor<yourEntity>, QuerydslBinderCustomizer<QyourEntity> {
    @Override
    default void customize(final QuerydslBindings bindings, final QyourEntity root) {
        bindings.bind(String.class).first((StringPath path, String value)-> path.eq(value));
    }
}