问题
I want to do something similar to XMLStreamReader example @BlaiseDoughan gave in his response to JAXB filtered parsing however I need to make the filtering decision based on sub elements not current node attributes.
XMLStreamReader does not have a peek API like XMLEventReader. For example, I want to unmarshall the following XML into a Gump object whose records list ends up only containing 1 item, the record whose associated name does not start with "Filtered-".
I'm using Eclipselink 2.3.2v20111124-r10461
<gump>
<foo>Some text</foo>
<bar>1.245</bar>
<records>
<record>
<name>Filtered-Counter</name>
<value>1</value>
</record>
<record>
<name>Golden</name>
<value>shiny</value>
</record>
</records>
<baz>1234</baz>
</gump>
Gump.java
@XmlRootElement(name = "gump")
@XmlAccessorType(XmlAccessType.FIELD)
public class Gump implements Serializable {
private String foo;
private String bar;
private String baz;
@XmlElementWrapper
@XmlElement(name = "record")
private List<Record> records;
// .. Field getters/setters
public Gump() {
records = new ArrayList<>();
}
}
回答1:
The easiest thing to do would be to do a regular unmarshal, and then use an unmarshal listener that cleans up the collection on the after unmarshal event.
- http://docs.oracle.com/javase/7/docs/api/javax/xml/bind/Unmarshaller.Listener.html
- http://docs.oracle.com/javase/7/docs/api/javax/xml/bind/Unmarshaller.html#unmarshalEventCallback
来源:https://stackoverflow.com/questions/22695541/filtering-out-elements-based-on-sub-elements-with-xmlstreamreader-and-streamfilt