java - Jersey JSON/JAXB 忽略或看不到 POJO 中的 "some"公共(public)属性

Question

我有一个 POJO，我正在尝试使用 jersey 序列化作为休息 api 响应。仅部分属性被序列化。 getter 返回的值不为 null。

如果我尝试对属性进行排序，则会针对“缺失”属性抛出 IllegalAnnotationExceptions，就好像它们不存在一样。

我还有其他几个 POJO 可以正常工作。我有一个对象没有看到任何属性，而另一个对象则有 10 个属性中的 7 个可见。

有人可以告诉我发生了什么事吗？并建议如何修复它？

import javax.xml.bind.annotation.XmlRootElement;
import javax.xml.bind.annotation.XmlType;
import java.io.Serializable;
import java.util.Date;

@XmlType(propOrder = { "startDateTime","endDateTime","durationMinutes","remainingMinutes","percentComplete","nodesDiscovered","nodesTried",
                        "totalNodes", "discoveryCompleted","canceledFlag" })
@XmlRootElement
public class DiscoveryStatus implements Serializable {
    private Number discoveryCompleted=0;
    private Date  startDateTime = new Date();
    private Date  endDateTime  = new Date();

    private Number startMS =20;
    private Number currMS =20;

    private Number durationMinutes =AppSettings.DiscoveryNodeMulticastDurationMins;
    private Number remainingMinutes =20;

    private Boolean canceledFlag=false;
    private Number percentComplete =0;
    private Number nodesDiscovered =0;
    private Number nodesTried =0;
    private Number totalNodes =0;

    public DiscoveryStatus(){
        totalNodes =1;
    }

    // Seen
    public Date getStartDateTime(){
        return this.startDateTime;
    }

    // Seen
    public Number getDurationMinutes(){
        return this.durationMinutes;
    }

    public Number getRemainingMinutes(){
        return this.remainingMinutes;
    }

    // Seen
    public Date getEndDateTime(){
        return this.endDateTime;
    }

    public Number getDiscoveryCompleted(){
        return this.discoveryCompleted;
    }

    public Boolean getCanceledFlag(){
        return this.canceledFlag;
    }

    // Seen
    public Number getPercentComplete(){
        return this.percentComplete;
    }

    // Seen
    public Number getNodesDiscovered(){
        return this.nodesDiscovered;
    }

    // Seen
    public Number getNodesTried(){
        return this.nodesTried;
    }

    // Seen
    public Number getTotalNodes(){
        return this.totalNodes;
    }

    public Number setDiscoveryCompleted(boolean discoveryCompleted ) {
        // gm this.discoveryCompleted =discoveryCompleted;
        return this.discoveryCompleted;
    }

    public Number setPercentComplete (Number percentComplete) {
        this.percentComplete =percentComplete;
        return this.percentComplete;
    }

    public Number setNodesDiscovered(Number nodesDiscovered) {
        this.nodesDiscovered =nodesDiscovered;
        return this.nodesDiscovered;
    }

    public Number setNodesTried(Number nodesTried) {
        this.nodesTried =nodesTried;
        return this.nodesTried;
    }

    public Number setTotalNodes(Number totalNodes) {
        this.totalNodes =totalNodes;
        return this.totalNodes;
    }

    public Date setStartDateTime(Date  startDateTime) {
        this.startDateTime = startDateTime;
        return this.startDateTime;
    }

    public Date setStartDateTime() {
        this.startDateTime = new Date();
        return this.startDateTime;
    }

    public Date setEndDateTime(Date  endDateTime) {
        this.endDateTime = endDateTime;
        return this.endDateTime;
    }

    public Date setEndDateTime() {
        this.endDateTime = new Date();
        return this.endDateTime;
    }

    public Number setDurationMinutes(Number  durationMinutes) {
        this.durationMinutes = durationMinutes;
        return this.durationMinutes;
    }

    public Number setDurationMinutes() {
        this.durationMinutes = AppSettings.DiscoveryNodeMulticastDurationMins;
        return this.durationMinutes;
    }

}

Answer 1

您的模型存在问题

您的模型存在一些问题:

没有 Setter 的 Getter

默认情况下，JAXB 不会将没有相应 set 方法的 get 方法视为属性。但是，如果您使用 @XmlElement 注释它，那么它就会。

@XmlElement
public Number getRemainingMinutes(){
    return this.remainingMinutes;
}

@XmlElement
public Boolean getCanceledFlag(){
    return this.canceledFlag;
}

获取/设置方法不匹配

JAXB 将期望 get 方法的返回类型与 set 方法的参数类型匹配。

public Number getDiscoveryCompleted(){
    return this.discoveryCompleted;
}

public Number setDiscoveryCompleted(boolean discoveryCompleted ) {
    // gm this.discoveryCompleted =discoveryCompleted;
    return this.discoveryCompleted;
}

这两个问题的解决方案

您可以使用 @XmlAccessorType 注释告诉 JAXB 使用字段访问，而不是使用默认的属性访问。对于您的模型，这意味着使用 @XmlTransient 注释几个未映射的字段(请参阅: http://blog.bdoughan.com/2012/04/jaxb-and-unmapped-properties.html )。

import javax.xml.bind.annotation.*;

import java.io.Serializable;
import java.util.Date;

@XmlType(propOrder = { "startDateTime","endDateTime","durationMinutes","remainingMinutes","percentComplete","nodesDiscovered","nodesTried",
                        "totalNodes", "discoveryCompleted","canceledFlag" })
@XmlRootElement
@XmlAccessorType(XmlAccessType.FIELD)
public class DiscoveryStatus implements Serializable {
    private Number discoveryCompleted=0;
    private Date  startDateTime = new Date();
    private Date  endDateTime  = new Date();

    @XmlTransient
    private Number startMS =20;

    @XmlTransient
    private Number currMS =20;

    private Number durationMinutes =AppSettings.DiscoveryNodeMulticastDurationMins;
    private Number remainingMinutes =20;

    private Boolean canceledFlag=false;
    private Number percentComplete =0;
    private Number nodesDiscovered =0;
    private Number nodesTried =0;
    private Number totalNodes =0;

    public DiscoveryStatus(){
        totalNodes =1;
    }

}

了解更多信息

• http://blog.bdoughan.com/2012/02/jaxbs-xmltype-and-proporder.html