我对简单的xml库还不熟悉。我真的很喜欢,但我有个问题。
下面是我的类(删除了一些代码以使其更简洁):
@Root
@ElementList
public class MyArrayList<E> extends ArrayList<E>{
public void ToXml() throws Exception{
Serializer serializer = new Persister();
File file = new File("somewhere in my file system");
serializer.write(this, file);
}
}
-
@Root
public abstract class MediaEntry implements Serializable {
private static final long serialVersionUID = 1L;
@Element
public String Title;
@Element
public String Description;
@Element
public String Url;
@Element
public String LocalPath;
public MediaEntry(String title, String description,
String url, String localPath) {
Title= title;
Description= description;
Url= url;
LocalPath= localPath;
}
}
-
public class VideoEntry extends MediaEntry {
private static final long serialVersionUID = 1L;
public VideoEntry(String title, String description,
String url, String localPath) {
super(title, description, url, localPath);
}
}
当我实例化myarraylist时,添加一些videoentries并调用toxml,我只得到一个空的根ie。
<MyArrayList />
我该怎么解决?这和myarraylist是泛型有关吗?
最佳答案
列表必须是元素的成员(并且没有独立的类)才能获得所需的行为,您可以将elementList设置为内联,这样就没有父元素了。
@Root
public class MyArrayList<E> {
@ElementList(inline=true)
ArrayList<E> list = new ArrayList<E>();
public boolean add(E entry) {
return list.add(entry);
}
public void ToXml() throws Exception {
Serializer serializer = new Persister();
File file = new File("somewhere in my file system");
serializer.write(this, file);
}
}
只是想到了另一个可能更好的解决方案(你可以访问所有列表函数-但我不确定是否有任何副作用,所以我保留原来的解决方案)
@Root
public class MyArrayList<E> extends ArrayList<E> {
@ElementList(inline=true)
MyArrayList<E> list = this;
public void ToXml() throws Exception {
Serializer serializer = new Persister();
File file = new File("somewhere in my file system");
serializer.write(this, file);
}
}
要反序列化,必须为simplexml声明,该simplexml的哪个元素用于哪个构造函数参数:
@Root
public abstract class MediaEntry implements Serializable {
private static final long serialVersionUID = 1L;
@Element
public String Title;
@Element
public String Description;
@Element
public String Url;
@Element
public String LocalPath;
public MediaEntry(@Element(name = "Title") String title,
@Element(name = "Description") String description,
@Element(name = "Url") String url,
@Element(name = "LocalPath") String localPath) {
Title = title;
Description = description;
Url = url;
LocalPath = localPath;
}
}
顺便说一句,如果您只是开始编写Java,那么您可以考虑阅读Java代码约定——以大写字母开始方法和变量名称并不是一个好的做法(这样您就可以防止习惯坏习惯;—)