在 Spring Rest API 中配置 LocaldateTime [英] Configure LocaldateTime in Spring Rest API

问题描述

我使用 Java 10 和最新的 Spring spring-boot-starter-parent 2.1.0.RELEASE

I use Java 10 with latest Spring spring-boot-starter-parent 2.1.0.RELEASE

POM 配置:

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.0.RELEASE</version>
    </parent>

    <dependencies>          
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.dataformat</groupId>
            <artifactId>jackson-dataformat-xml</artifactId>
            <version>2.9.7</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-annotations</artifactId>
            <version>2.9.7</version>
            <scope>compile</scope>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.module</groupId>
            <artifactId>jackson-module-jaxb-annotations</artifactId>
            <version>2.9.7</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.jaxrs</groupId>
            <artifactId>jackson-jaxrs-json-provider</artifactId>
            <version>2.9.7</version>
        </dependency>
        <dependency>
            <groupId>commons-io</groupId>
            <artifactId>commons-io</artifactId>
            <version>2.6</version>
        </dependency>
        <dependency>
            <groupId>org.codehaus.woodstox</groupId>
            <artifactId>woodstox-core-asl</artifactId>
            <version>4.4.1</version>
        </dependency>
        <dependency>
            <groupId>javax.xml.bind</groupId>
            <artifactId>jaxb-api</artifactId>
            <version>2.3.1</version>
        </dependency>
        <dependency>
            <groupId>com.sun.xml.bind</groupId>
            <artifactId>jaxb-core</artifactId>
            <version>2.3.0.1</version>
        </dependency>
        <dependency>
            <groupId>com.sun.xml.bind</groupId>
            <artifactId>jaxb-impl</artifactId>
            <version>2.3.1</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>org.mapstruct</groupId>
            <artifactId>mapstruct-jdk8</artifactId>
            <version>1.2.0.Final</version>
        </dependency>
        <dependency>
            <groupId>org.jxls</groupId>
            <artifactId>jxls-poi</artifactId>
            <version>1.0.15</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
            <exclusions>
                <exclusion>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-starter-tomcat</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>javax</groupId>
            <artifactId>javaee-api</artifactId>
            <version>8.0</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.security.oauth</groupId>
            <artifactId>spring-security-oauth2</artifactId>
            <version>2.3.4.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.security.oauth.boot</groupId>
            <artifactId>spring-security-oauth2-autoconfigure</artifactId>
            <version>2.1.0.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-security</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-amqp</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.session</groupId>
            <artifactId>spring-session-core</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-mail</artifactId>
        </dependency>
    </dependencies>

休息端点:

    @GetMapping("{id}")
    public ResponseEntity<?> get(@PathVariable String id) {
        return transactionRepository
                .findById(Integer.parseInt(id))
                .map(mapper::toDTO)
                .map(ResponseEntity::ok)
                .orElseGet(() -> notFound().build());
    }

DTO:

public class PaymentTransactionsDTO {

    private Integer id;

    private String status;

    private LocalDateTime created_at;

    private String merchant;
    .... getters and setters
}

但是当我尝试为 LocalDateTime created_at 返回 JSON 数据时，我得到空结果.我想 LocalDateTime 没有正确转换为 JSON 值.

But when I try to return JSON data for LocalDateTime created_at I get empty result. I suppose that LocalDateTime is not properly converted into JSON value.

你能建议我如何解决这个问题吗?

Can you advice how I can fix this issue?

推荐答案

JSON 序列化由 Jackson 的 ObjectMapper 驱动，我建议对其进行显式配置.为了正确序列化 Java 8 日期和时间对象，请确保

JSON serialization is driven by Jackson's ObjectMapper, which I recommend configuring explicitely. For proper serialization of the Java 8 date and time objects, make sure to

• 注册JavaTimeModule
• 禁止将日期写入时间戳
• 设置日期格式(使用StdDateFormat)

StdDateFormat 说明:

标准日期使用的默认 DateFormat 实现序列化器和反序列化器.对于序列化默认使用ISO-8601 兼容格式(格式字符串yyyy-MM-dd'T'HH:mm:ss.SSSZ")对于反序列化，ISO-8601 和 RFC-1123.

Default DateFormat implementation used by standard Date serializers and deserializers. For serialization defaults to using an ISO-8601 compliant format (format String "yyyy-MM-dd'T'HH:mm:ss.SSSZ") and for deserialization, both ISO-8601 and RFC-1123.

推荐配置:

@Configuration
public class JacksonConfig {

    @Bean
    public ObjectMapper objectMapper() {
        return new ObjectMapper()
            .setAnnotationIntrospector(new JacksonAnnotationIntrospector())
            .registerModule(new JavaTimeModule())
            .setDateFormat(new StdDateFormat())
            .disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);
    }

}}

序列化日期和时间对象的示例:

Examples of serialized date and time objects:

• LocalDate:2018-11-21
• LocalTime:11:13:13.274
• LocalDateTime:2018-11-21T11:13:13.274
• ZonedDateTime:2018-11-21T11:13:13.274+01:00

编辑:独立依赖项(已经包含在 spring-boot-starter-web 中):

Edit: standalone dependencies (already included transitively in spring-boot-starter-web):

• com.fasterxml.jackson.core:jackson-annotations
• com.fasterxml.jackson.core:jackson-databind
• com.fasterxml.jackson.datatype:jackson-datatype-jsr310

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