我可以使用“包装器”类来编组ObservableList,如下所示.但是我无法将其解组回以前的wrapper类.
这个想法是:
我有一个“费用”的ObservableList.我将此列表放入包装器类中,并将该类保存为XML.结果看起来像这样:
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<List>
<root>
<category>[none]</category>
<period>Year</period>
<title>asd</title>
<value>354</value>
</root>
</List>
我无法将其带回包装对象.
我真的很感谢任何帮助.
主类JAXBContext(对所有人可见):
JAXBContext jc = JAXBContext.newInstance(MyWrapperForList.class, Expense.class);
主类SAVEBUTTON:
public class SaveButtonListener implements EventHandler<ActionEvent> {
@Override
public void handle(ActionEvent arg0) {
File serializedFile = new File(PATH);
try {
if (serializedFile.exists() == false)
serializedFile.createNewFile();
PrintWriter xmlOut = new PrintWriter(serializedFile);
Marshaller m = jc.createMarshaller();
m.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
List<Expense> saveList = new ArrayList<>();
saveList.addAll(data);
MyWrapperForList<Expense> wrapper = new MyWrapperForList<>(saveList);
JAXBElement<MyWrapperForList> jaxbElement = new JAXBElement<>(
new QName("List"), MyWrapperForList.class, wrapper);
m.marshal(jaxbElement, xmlOut);
xmlOut.flush();
xmlOut.close();
主类LOADBUTTON:
public class LoadButtonListener implements EventHandler<ActionEvent> {
@Override
public void handle(ActionEvent arg0) {
try {
Unmarshaller unmarshaller = jc.createUnmarshaller();
StreamSource xml = new StreamSource(PATH);
MyWrapperForList<Expense> unwrapper = unmarshaller.unmarshal(xml,
MyWrapperForList.class).getValue();
List<Expense> tempList = new ArrayList<>();
tempList.addAll(unwrapper.getItems());
System.out.println(tempList.get(0).getTitle());
} catch (Exception e) {
e.printstacktrace();
}
}
}
包装类:
公共类MyWrapperForList {
private List<Expense> list;
public MyWrapperForList() {
list = new ArrayList<>();
}
public MyWrapperForList(List<Expense> expenses) {
this.list = expenses;
}
@XmlAnyElement(lax=true)
public List<Expense> getItems() {
return list;
}
}
费用类:
@XmlRootElement(name =“ root”)
公共类费用{
private String title;
private String category;
private String period;
private String value;
public Expense() {} //Default constructor is needed for XML-handling
public Expense(String title, String value, String period, String category) {
this.title = title;
this.value = value;
this.period = period;
this.category = category;
}
@XmlElement(name = "title")
public String getTitle() {
return this.title;
}
@XmlElement(name = "category")
public String getCategory() {
return this.category;
}
@XmlElement(name = "period")
public String getPeriod() {
return this.period;
}
@XmlElement(name = "value")
public String getValue() {
return this.value;
}
}
我从Blaise Doughan使用了本教程:http://blog.bdoughan.com/2012/11/creating-generic-list-wrapper-in-jaxb.html
解决方法:
MyListWrapper
如果希望MyWrapperForList解组持有ObservableList实例的实例,则需要通过以下方式之一设置类.
类型ObservableList的属性
import javax.xml.bind.annotation.XmlAnyElement;
import javafx.collections.*;
public class MyWrapperForList<T> {
private ObservableList<T> list;
public MyWrapperForList() {
list = FXCollections.<T>observableArrayList();
}
public MyWrapperForList(ObservableList<T> list) {
this.list = list;
}
@XmlAnyElement(lax = true)
public ObservableList<T> getItems() {
return list;
}
}
List属性初始化为ObservableList的实例
import java.util.List;
import javax.xml.bind.annotation.XmlAnyElement;
import javafx.collections.*;
public class MyWrapperForList<T> {
private List<T> list = FXCollections.<T>observableArrayList();
public MyWrapperForList() {
list = FXCollections.<T>observableArrayList();
}
public MyWrapperForList(List<T> list) {
this.list = list;
}
@XmlAnyElement(lax = true)
public List<T> getItems() {
return list;
}
}
示范代码
输入(nub.xml)
<List>
<root>
<category>[none]</category>
<period>Year</period>
<title>dfg</title>
<value>4</value>
</root>
<root>
<category>[none]</category>
<period>Year</period>
<title>ROBO</title>
<value>1234</value>
</root>
</List>
演示
import java.util.List;
import javax.xml.bind.JAXBContext;
import javax.xml.bind.Unmarshaller;
import javax.xml.transform.stream.StreamSource;
public class Demo {
public static void main(String[] args) throws Exception {
JAXBContext jc = JAXBContext.newInstance(MyWrapperForList.class, Expense.class);
//UNMARSHALLING
Unmarshaller unmarshaller = jc.createUnmarshaller();
StreamSource xml = new StreamSource("src/forum18594548/nub.xml");
MyWrapperForList<Expense> wrapper = (MyWrapperForList<Expense>) unmarshaller.unmarshal(xml, MyWrapperForList.class).getValue();
List<Expense> data = wrapper.getItems();
System.out.println(data.getClass());
for(Expense expense : data) {
System.out.println(expense);
}
}
}
产量
class com.sun.javafx.collections.ObservableListWrapper
forum18594548.Expense@789df61d
forum18594548.Expense@4a8927c8
UPDATE
First: Thanks for you work Blaise!! I’m really glad for what you do to
me! I tried what you wrote here (it was nearly the same as I had) and
I got a similar (same type of) output as you got. BUT the objects in
the lists are all referenced with null. If I write
System.out.println(data.get(0).getTitle()); it says null. There is the
exact amount of objects in the list, but all attributes are referenced
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