使用泽西客户端，Java8DataAPI (Jsr310)出现问题

Question

我正在使用jersey来使用REST服务来执行一个小的PoC，而且我在LocalDateTime格式的字段中遇到了问题。REST服务响应如下：

{
    "id": 12,
    "infoText": "Info 1234",
    "creationDateTime": "2001-12-12T13:40:30"
}

我的实体类：

package com.my.poc.jerseyclient;

import java.time.LocalDateTime;

public class Info {

    private Long id;
    private String infoText;
    private LocalDateTime creationDateTime;

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getInfoText() {
        return infoText;
    }

    public void setInfoText(String infoText) {
        this.infoText = infoText;
    }

    public LocalDateTime getCreationDateTime() {
        return creationDateTime;
    }

    public void setCreationDateTime(LocalDateTime creationDateTime) {
        this.creationDateTime = creationDateTime;
    }

}

Pom.xml中的依赖项：

<dependencies>
        <dependency>
            <groupId>org.glassfish.jersey.core</groupId>
            <artifactId>jersey-client</artifactId>
            <version>2.21</version>
        </dependency>

        <dependency>
            <groupId>com.fasterxml.jackson.jaxrs</groupId>
            <artifactId>jackson-jaxrs-json-provider</artifactId>
            <version>2.6.1</version>
        </dependency>

        <dependency>
            <groupId>com.fasterxml.jackson.datatype</groupId>
            <artifactId>jackson-datatype-jsr310</artifactId>
            <version>2.6.1</version>
        </dependency>
    </dependencies>

我的代码与jersey客户端一起编写了GET /api/info/123：

Client client = ClientBuilder.newClient(new ClientConfig().register(JacksonJsonProvider.class);
WebTarget webTarget = client.target("http://localhost:8080/api/").path("info/");
Response response = webTarget.path("123").request(MediaType.APPLICATION_JSON_TYPE).get();
System.out.println("GET Body (object): " + response.readEntity(Info.class));

我得到了这样的例外：

...
Caused by: com.fasterxml.jackson.databind.JsonMappingException: Can not instantiate value of type [simple type, class java.time.LocalDateTime] from String value ('2001-12-12T13:40:30'); no single-String constructor/factory method
 at [Source: org.glassfish.jersey.message.internal.ReaderInterceptorExecutor$UnCloseableInputStream@21b2e768; line: 1, column: 32] (through reference chain: com.my.poc.jerseyclient.Info["creationDateTime"])
...

我遗漏了什么？我在RestTemplate (Spring客户端)中尝试了这一点，它在没有任何配置的情况下工作得很好。

Answer 1

jsr310模块仍然需要向杰克逊注册。您可以在ContextResolver中作为seen here注册Jsr310Module，在ObjectMapper中注册Jsr310Module。

ObjectMapper mapper = new ObjectMapper();
mapper.registerModule(new JSR310Module());

然后将ContextResolver注册到客户端。将发生的情况是，JacksonJsonProvider应该调用getContext方法，并检索用于(反)序列化的ObjectMapper。

您还可以在服务器端使用相同的ContextResolver。如果您只需要在客户机上使用此功能，则另一种方法是使用JacksonJsonProvider简单地构造ObjectMapper。稍微简单一点

new JacksonJsonProvider(mapper)

Answer 2

为了客户端的功能，将所有内容组合在一起：

ObjectMapper mapper = new ObjectMapper();
mapper.registerModule(new JSR310Module());

JacksonJsonProvider provider = new JacksonJsonProvider(mapper);
Client client = ClientBuilder.newClient(new ClientConfig().register(provider));