Question

我决定让Jackson XML有机会将XML字符串转换为POJO。

所以我使用了以下很棒的web site来从我的xml字符串生成pojo。

因此，它创建了我需要的类，然后我尝试将xml值读入这些对象。

不幸的是，有些值在对象中设置为null，我无法找出原因：

这是xml字符串的开头：

<?xml version="1.0" encoding="UTF-8"?>
<schedule xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" generated_at="2018-02-23T16:55:45+00:00" xmlns="http://schemas.thesite.com/jobsapi/v1/myjob" xsi:schemaLocation="http://schemas.thesite.com/jobsapi/v1/myjob http://schemas.thesite.com/asb/myjob/v1/xml/endpoints/myjob/schedule.xsd">
    <job_event id="sr:task:12004724" scheduled="2018-02-23T17:00:00+00:00" start_time_tbd="false" status="not_started">
        <task type="group" number="23"/>

我所拥有的课程是：

public class Schedule
{
    private String generated_at;
    private String xmlns;
    private Job_event[] job_events;

    public String getGenerated_at ()
    {
        return generated_at;
    }

    public void setGenerated_at (String generated_at)
    {
        this.generated_at = generated_at;
    }

    public String getXmlns ()
    {
        return xmlns;
    }

    public void setXmlns (String xmlns)
    {
        this.xmlns = xmlns;
    }

    public Job_event[] getjob_events ()
    {
        return job_events;
    }

    public void setjob_events (Job_event[] job_events)
    {
        this.job_events = job_events;
    }

    @Override
    public String toString()
    {
        return "Schedule [generated_at = "+generated_at+", xmlns = "+xmlns+", job_events = "+job_events+"]";
    }
}

和

public class Job_event {

    private String id;
    private String scheduled;
    private String start_time_tbd;
    private String status;

        //more fields, getters and setters   
}

然后，我用它将字符串转换为pojos：

ObjectMapper xmlMapper = new XmlMapper();
xmlMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
Schedule sched = xmlMapper.readValue(xmlString, Schedule.class);
Job_event[] job_events = sched.getJob_events();

我在job_events中的每个事件值中都发现成员值如id和status，其余为null。

为什么？ xml字符串没问题。

谢谢！

Answer 1

您可以通过执行以下操作来解决此问题

使用@JacksonXmlProperty(isAttribute = true)注释将Pojo字段映射到XML属性
使用List代替数组
使用@JacksonXmlElementWrapper(useWrapping = false)注释表示您的列表List<JobEvent>表示为重复的XML元素。
我认为您应annotate your fields localName，以便与Java命名约定保持兼容

之后它看起来像

@JsonIgnoreProperties(ignoreUnknown = true)
public class JobEvent {
    @JacksonXmlProperty(isAttribute = true)
    private String id;
    @JacksonXmlProperty(isAttribute = true)
    private String scheduled;
    @JacksonXmlProperty(isAttribute = true, localName = "start_time_tbd")
    private String startTimeTbd;
    @JacksonXmlProperty(isAttribute = true)
    private String status;

    @Override
    public String toString() {
        return id + " " + scheduled + " " + " " + startTimeTbd + " " + status;
    }
}

Schedule.java

public class Schedule {
    @JacksonXmlProperty(isAttribute = true,localName="generated_at")
    public String generatedAt;
    @JacksonXmlProperty(isAttribute = true)
    public String xmlns;
     @JacksonXmlElementWrapper(useWrapping = false)
    public List<JobEvent> job_event;

    @Override
    public String toString()
    {
        return "Schedule [generated_at = "+generatedAt+", xmlns = "+xmlns+", job_events = "+job_event.toString()+"]";
    }
}

TESTCALL

@Test
    public void readXmlToSelfDefinedPojo2() throws Exception {

        ObjectMapper mapper = new XmlMapper();
        Schedule pojo = mapper.readValue(
                        Thread.currentThread().getContextClassLoader().getResourceAsStream("48963966.xml"),
                        Schedule.class);
        System.out.println(pojo + "");
    }

对于XML文件48963966.xml

将打印

Schedule [generated_at = 2018-02-23T16:55:45+00:00, xmlns = null, job_events = [sr:task:12004724 2018-02-23T17:00:00+00:00  false not_started, sr:task:12004725 2018-02-25T17:00:00+00:00  false not_started]]

FasterXML - Jackson XML扩展在pojo中将值转换为null

1 个答案: