Question

我使用Spring-boot 2.0.1和WebFlux作为Rest服务器。

在我的RestController中我想自动反序列化一个对象（Product）。但是我得到了Jackson错误，好像没有注册ParameterNamesModule。

引起： com.fasterxml.jackson.databind.exc.InvalidDefinitionException：不能构造com.truc.Product的实例（没有创建者，就像默认构造，存在）：不能从Object值反序列化（没有委托 - 或者基于财产的创作者）[来源：UNKNOWN; line：-1，column：-1] 在 com.fasterxml.jackson.databind.exc.InvalidDefinitionException.from（InvalidDefinitionException.java:67）在 com.fasterxml.jackson.databind.DeserializationContext.reportBadDefinition（DeserializationContext.java:1451）在 com.fasterxml.jackson.databind.DeserializationContext.handleMissingInstantiator（DeserializationContext.java:1027）在 com.fasterxml.jackson.databind.deser.BeanDeserializerBase.deserializeFromObjectUsingNonDefault（BeanDeserializerBase.java:1290）在 com.fasterxml.jackson.databind.deser.BeanDeserializer.deserializeFromObject（BeanDeserializer.java:326）在 com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize（BeanDeserializer.java:159）在 com.fasterxml.jackson.databind.ObjectReader._bind（ObjectReader.java:1574）在 com.fasterxml.jackson.databind.ObjectReader.readValue（ObjectReader.java:965）在 org.springframework.http.codec.json.AbstractJackson2Decoder.lambda $ decodeInternal $ 0（AbstractJackson2Decoder.java:113） ...省略了287个常见帧

我的pom中有jackson-module-parameter-names

 <dependency>
     <groupId>com.fasterxml.jackson.module</groupId>
     <artifactId>jackson-module-parameter-names</artifactId>
 </dependency>

这是RestController中的路由

@ResponseStatus(HttpStatus.CREATED)
@RequestMapping(method = RequestMethod.POST)
public Mono<Entity<Product>> postProduct(@RequestBody Product product) {
    return productService.insert(product);
}

如果我尝试手动反序列化，它可以工作：

@Autowired
private ObjectMapper objectMapper;
...
@ResponseStatus(HttpStatus.CREATED)
@RequestMapping(method = RequestMethod.POST)
public Mono<Entity<Product>> postProduct(ServerWebExchange exchange) {
    return exchange.getRequest().getBody()
            .last().flatMap(buffer -> {
        try {
            Product product = objectMapper.readValue(buffer.asInputStream(), Product.class);
            return productService.insert(product);
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    });
}

这是我的Product.class

package com.truc;

import java.time.LocalDate; import java.util.Optional;

public final class Product {
    public static final String PREFIX = "PT";

    public final String description;
    public final String shortDescription;
    public final String sku;
    public final float weight;
    public final LocalDate newSince;
    public final LocalDate newUntil;
    public final Status status;
    public final Visibility visibility;
    public final String metaKeywords;

    public Product(String description, String shortDescription, String sku, Float weight,
                   LocalDate newSince, LocalDate newUntil, Status status, Visibility visibility, String metaKeywords) {
        this.description = description;
        this.shortDescription = shortDescription;
        this.sku = sku;
        this.weight = Optional.ofNullable(weight).orElse(0f);
        this.newSince = newSince;
        this.newUntil = newUntil;
        this.status = status;
        this.visibility = visibility;
        this.metaKeywords = metaKeywords;
    }

    public enum Status {
        ACTIVE, INACTIVE
    }

    public enum Visibility {
        FULL, CATALOG, SEARCH, NONE
    } 
}

如果我理解@JsonCreator 2.9之后不需要jackson-databind，我会使用jackson 2.9.5

如果我添加@JsonCreator，我会收到新错误415 Unsupported Content-Type 'application/json' ...

我不明白我哪里错了？

由于

Answer 1

解释here @EnableWebFlux停用所有webflux自动配置。我在Configuration类中使用它而不使用WebFluxConfigurer扩展类。

当我删除@EnableWebFlux它再次工作时，ObjectMapper按预期配置。

所以没关系感谢

Answer 2

您必须在RequestBody类（即ProductClass）中添加默认构造函数，然后它将起作用

@RequestBody对象不会自动反序列化

2 个答案: