java - XStream - 解析嵌套元素(跳过父元素)

Question

我有以下 XML，我正在尝试使用 XStream 解析它。问题是，一切正常，直到我达到<Keywords>...</Keywords>。元素。

我想获取所有 <KEYWORD>元素，无需创建一个类来处理 <KEYWORDS>

示例.XML

<CATALOG>
  <PRODUCTS>
    <PRODUCT>
      <PRODUCTOID>123</PRODUTOID>
      <PRODUCTNAME>TEST NAME</NOMEPRODUTO>
      <DESCRIPTION>TEST DESCRIPTION</DESCRIPTION>
      <KEYWORDS>
        <KEYWORD>keyword_1</KEYWORD>
        <KEYWORD>keyword_2</KEYWORD>
        <KEYWORD>keyword_3</KEYWORD>
        <KEYWORD>keyword_n</KEYWORD>
      <KEYWORDS>
    </PRODUCT>
  </PRODUCTS>
</CATALOG>

目录.java

@XStreamAlias("CATALOG")
public class Catalog {

    @XStreamAlias("PRODUCTS")
    private List<Product> products;

   // Getters and Setters

}

产品.java

@XStreamAlias("PRODUCT")
public class Product {

    @XStreamAlias("PRODUCTID")
    private String id;

    @XStreamAlias("PRODUCTNAME")
    private String name;

    @XStreamAlias("DESCRIPTION")
    private String description;


   // @XStreamImplicit(itemFieldName = "KEYWORD")
   // the above line works, *IF* I delete the parent node `<KEYWORDS>`,
   // but that's not the case, I have to deal with it  

   // @StreamAlias("KEYWORDS/KEYWORD")
   // this doesn't work

   @StreamAlias("KEYWORDS")
   // and this returns the error I'm posting below after this class
   private List<String> keywords;

   // Getters and Setters

}

XStreamTest.java

public class XStreamTest {

    public static void main(String[] args) {

    String filepath = "Sample.xml";

    try {
        FileReader reader = new FileReader(filepath);
        XStream xstream = new XStream();

        xstream.processAnnotations(Catalog.class);
        xstream.processAnnotations(Product.class);

        Catalog catalog = (Catalog) xstream.fromXML(reader);
        System.out.println(catalog.getProducts().get(0).getKeywords().get(0));
    }

    catch (FileNotFoundException e) {
        e.printStackTrace();
    }

}

在当前设置下，这就是我得到的(我知道为什么我得到这个......我没有将元素 <KEYWORD> 映射到任何地方。

但我真的不想想要创建另一个类，说“Keyword.java”只是为了处理这个<KEYWORDS> (就像我管理 <PRODUCT> 元素中的元素一样。

无论如何我可以解决这个问题(无需再上一个类)吗？

Exception in thread "main" com.thoughtworks.xstream.converters.ConversionException: KEYWORD: KEYWORD
---- Debugging information ----
message             : KEYWORD
cause-exception     : com.thoughtworks.xstream.mapper.CannotResolveClassException
cause-message       : KEYWORD
class               : java.util.ArrayList
required-type       : java.util.ArrayList
converter-type      : com.thoughtworks.xstream.converters.collections.CollectionConverter
path                : /CATALOG/PRODUCTS/PRODUCT/KEYWORDS/KEYWORD
line number         : 9
class[1]            : obscured_package.model.Product
converter-type[1]   : com.thoughtworks.xstream.converters.reflection.ReflectionConverter
class[2]            : obscured_package.model.Catalog
version             : 1.4.8
-------------------------------
    at com.thoughtworks.xstream.core.TreeUnmarshaller.convert(TreeUnmarshaller.java:79)
    at com.thoughtworks.xstream.core.AbstractReferenceUnmarshaller.convert(AbstractReferenceUnmarshaller.java:65)
    at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:66)
    at com.thoughtworks.xstream.converters.reflection.AbstractReflectionConverter.unmarshallField(AbstractReflectionConverter.java:480)
    at com.thoughtworks.xstream.converters.reflection.AbstractReflectionConverter.doUnmarshal(AbstractReflectionConverter.java:412)
    at com.thoughtworks.xstream.converters.reflection.AbstractReflectionConverter.unmarshal(AbstractReflectionConverter.java:263)
    at com.thoughtworks.xstream.core.TreeUnmarshaller.convert(TreeUnmarshaller.java:72)
    at com.thoughtworks.xstream.core.AbstractReferenceUnmarshaller.convert(AbstractReferenceUnmarshaller.java:65)
    at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:66)
    at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:50)
    at com.thoughtworks.xstream.converters.collections.AbstractCollectionConverter.readItem(AbstractCollectionConverter.java:71)
    at com.thoughtworks.xstream.converters.collections.CollectionConverter.addCurrentElementToCollection(CollectionConverter.java:98)
    at com.thoughtworks.xstream.converters.collections.CollectionConverter.populateCollection(CollectionConverter.java:91)
    at com.thoughtworks.xstream.converters.collections.CollectionConverter.populateCollection(CollectionConverter.java:85)
    at com.thoughtworks.xstream.converters.collections.CollectionConverter.unmarshal(CollectionConverter.java:80)
    at com.thoughtworks.xstream.core.TreeUnmarshaller.convert(TreeUnmarshaller.java:72)
    at com.thoughtworks.xstream.core.AbstractReferenceUnmarshaller.convert(AbstractReferenceUnmarshaller.java:65)
    at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:66)
    at com.thoughtworks.xstream.converters.reflection.AbstractReflectionConverter.unmarshallField(AbstractReflectionConverter.java:480)
    at com.thoughtworks.xstream.converters.reflection.AbstractReflectionConverter.doUnmarshal(AbstractReflectionConverter.java:412)
    at com.thoughtworks.xstream.converters.reflection.AbstractReflectionConverter.unmarshal(AbstractReflectionConverter.java:263)
    at com.thoughtworks.xstream.core.TreeUnmarshaller.convert(TreeUnmarshaller.java:72)
    at com.thoughtworks.xstream.core.AbstractReferenceUnmarshaller.convert(AbstractReferenceUnmarshaller.java:65)
    at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:66)
    at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:50)
    at com.thoughtworks.xstream.core.TreeUnmarshaller.start(TreeUnmarshaller.java:134)
    at com.thoughtworks.xstream.core.AbstractTreeMarshallingStrategy.unmarshal(AbstractTreeMarshallingStrategy.java:32)
    at com.thoughtworks.xstream.XStream.unmarshal(XStream.java:1206)
    at com.thoughtworks.xstream.XStream.unmarshal(XStream.java:1190)
    at com.thoughtworks.xstream.XStream.fromXML(XStream.java:1061)
    at br.com.multiplusfidelidade.ecommerce.netshoes.batch.App.main(App.java:21)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at com.intellij.rt.execution.application.AppMain.main(AppMain.java:140)
Caused by: com.thoughtworks.xstream.mapper.CannotResolveClassException: PALAVRA
    at com.thoughtworks.xstream.mapper.DefaultMapper.realClass(DefaultMapper.java:79)
    at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
    at com.thoughtworks.xstream.mapper.DynamicProxyMapper.realClass(DynamicProxyMapper.java:55)
    at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
    at com.thoughtworks.xstream.mapper.PackageAliasingMapper.realClass(PackageAliasingMapper.java:88)
    at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
    at com.thoughtworks.xstream.mapper.ClassAliasingMapper.realClass(ClassAliasingMapper.java:79)
    at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
    at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
    at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
    at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
    at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
    at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
    at com.thoughtworks.xstream.mapper.ArrayMapper.realClass(ArrayMapper.java:74)
    at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
    at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
    at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
    at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
    at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
    at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
    at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
    at com.thoughtworks.xstream.mapper.SecurityMapper.realClass(SecurityMapper.java:71)
    at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
    at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
    at com.thoughtworks.xstream.mapper.CachingMapper.realClass(CachingMapper.java:47)
    at com.thoughtworks.xstream.core.util.HierarchicalStreams.readClassType(HierarchicalStreams.java:29)
    at com.thoughtworks.xstream.converters.collections.AbstractCollectionConverter.readItem(AbstractCollectionConverter.java:70)
    at com.thoughtworks.xstream.converters.collections.CollectionConverter.addCurrentElementToCollection(CollectionConverter.java:98)
    at com.thoughtworks.xstream.converters.collections.CollectionConverter.populateCollection(CollectionConverter.java:91)
    at com.thoughtworks.xstream.converters.collections.CollectionConverter.populateCollection(CollectionConverter.java:85)
    at com.thoughtworks.xstream.converters.collections.CollectionConverter.unmarshal(CollectionConverter.java:80)
    at com.thoughtworks.xstream.core.TreeUnmarshaller.convert(TreeUnmarshaller.java:72)
    ... 35 more

Process finished with exit code 1

提前致谢!

Answer 1

我想如果你现在有“KEYWORD”的地方有“string”，你的XML会被正确解析。所以我想你的问题已经在这里得到解答:aliasing-contents-of-a-set-using-xstream

你可以尝试XStreamAliasType使用注释来完成此操作。