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[英]Xtream com.thoughtworks.xstream.mapper.CannotResolveClassException
[英]com.thoughtworks.xstream.mapper.CannotResolveClassException
這是我嘗試XStream的第一次。 但是當我嘗試解析我的xml文件時,我得到了這個異常:
Exception in thread "main" com.thoughtworks.xstream.mapper.CannotResolveClassException: root
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.CachingMapper.realClass(CachingMapper.java:45)
at com.thoughtworks.xstream.core.util.HierarchicalStreams.readClassType(HierarchicalStreams.java:29)
at com.thoughtworks.xstream.core.TreeUnmarshaller.start(TreeUnmarshaller.java:133)
at com.thoughtworks.xstream.core.AbstractTreeMarshallingStrategy.unmarshal(AbstractTreeMarshallingStrategy.java:32)
at com.thoughtworks.xstream.XStream.unmarshal(XStream.java:1157)
at com.thoughtworks.xstream.XStream.unmarshal(XStream.java:1141)
at com.thoughtworks.xstream.XStream.fromXML(XStream.java:1012)
at com.mmm.transport.se.xmleditor.xml.TestXML.test(TestXML.java:20)
at com.mmm.transport.se.xmleditor.domain.Main.main(Main.java:13)
所以我們可以看到錯誤發生在我的testXML類的第20行。 它看起來像這樣:
public class TestXML {
public void test() throws FileNotFoundException {
FileReader reader = new FileReader("xmlFiles/CoreDatamodel.xml");
XStream xstream = new XStream();
xstream.processAnnotations(Properties.class);
xstream.processAnnotations(Parameters.class);
xstream.processAnnotations(ObjType.class);
xstream.processAnnotations(Type.class);
Type data = (Type) xstream.fromXML(reader);
System.out.println(data);
}
}
第20行是這一行: xstream.processAnnotations(Parameters.class);
@XStreamAlias("param")
public class Parameters {
@XStreamAlias("DATATYPE")
private String datatype;
@XStreamAlias("DESCRIPTION")
private String description;
@XStreamAlias("MIN_NO")
private String min_no;
@XStreamAlias("MAX_NO")
private String max_no;
@XStreamAlias("ORDER1")
private String order1;
@XStreamAlias("NESTED")
private String nested;
@XStreamAlias("DEFAULT1")
private String default1;
@XStreamAlias("FORMAT")
private String format;
@XStreamAlias("PARAMETER")
private String parameter;
public Parameters(String datatype, String description, String min_no,
String max_no, String order1, String nested, String default1,
String format, String parameter) {
super();
setDatatype(datatype);
setDescription(description);
setMin_no(min_no);
setMax_no(max_no);
setOrder1(order1);
setNested(nested);
setDefault1(default1);
setFormat(format);
setParameter(parameter);
} //Getters and setters..
而xml看起來像這樣:
- <root>
- <info>
<CORE_NAME>DataModel_Core</CORE_NAME>
<CORE_VERSION>..</CORE_VERSION>
<CORE_PRODUCT_ID>...</CORE_PRODUCT_ID>
<ADAPTATION_NAME />
<ADAPTATION_VERSION />
<ADAPTATION_PRODUCT_ID />
</info>
- <type>
<OBJECT_TYPE>data</OBJECT_TYPE>
- <prop>
<DESCRIPTION>Site parameters</DESCRIPTION>
<PARENT>NULL</PARENT>
<VIRTUAL>0</VIRTUAL>
<VISIBLE>1</VISIBLE>
<PICTURE>NULL</PICTURE>
<HELP>10008</HELP>
<MIN_NO>1</MIN_NO>
<MAX_NO>1</MAX_NO>
<NAME_FORMAT>NULL</NAME_FORMAT>
</prop>
- <param>
<PARAMETER>nidRbc</PARAMETER>
<DATA_TYPE>INTEGER</DATA_TYPE>
<DESCRIPTION>RBC identity</DESCRIPTION>
<MIN_NO>1</MIN_NO>
<MAX_NO>1</MAX_NO>
<ORDER1>1</ORDER1>
<NESTED>0</NESTED>
<DEFAULT1>NULL</DEFAULT1>
<FORMAT>0:16382</FORMAT>
</param>
</type>
其他涉及的類看起來像這樣:
public class Type {
@XStreamImplicit(itemFieldName = "type")
private List types = new ArrayList();
}
public class ObjType {
@XStreamAlias("OBJECT_TYPE")
private String objectType;
public ObjType() {
} // Getters and setters
@XStreamAlias("prop")
public class Properties {
@XStreamAlias("DESCRIPTION")
private String description;
@XStreamAlias("PARENT")
private String parent;
@XStreamAlias("VIRTUAL")
private String virtual;
@XStreamAlias("VISIBLE")
private String visible;
@XStreamAlias("PICTURE")
private String picture;
@XStreamAlias("HELP")
private String help;
@XStreamAlias("MIN_NO")
private String min_no;
@XStreamAlias("MAX_NO")
private String max_no;
@XStreamAlias("NAME_FORMAT")
private String name_format;
public static Properties instance = null;
public static Properties getInstance() {
if (instance == null) {
instance = new Properties();
}
return instance;
}
public Properties() {
} // Getters and Setters.
這個錯誤的原因是什么?
獲得此異常的原因是因為您沒有xml元素根的表示和xml的信息。
因此,當XStream讀取該xml文件時,它正在搜索與根元素匹配的類。 如果您沒有定義別名/映射,它將嘗試將標記名稱作為類名。
所以,而不是:
public class Type {
@XStreamImplicit(itemFieldName = "type")
private List types = new ArrayList();
}
使用類似的東西:
@XStreamAlias("root")
public class Type {
private Info info;
@XStreamImplicit(itemFieldName = "type")
private List types = new ArrayList();
}
private class Info {
// ... define the attributes for the info element here.
}
為了您的參考,我已經格式化了您的xml以使事物更具可讀性:
<root>
<info>
<CORE_NAME>DataModel_Core</CORE_NAME>
<CORE_VERSION>..</CORE_VERSION>
<CORE_PRODUCT_ID>...</CORE_PRODUCT_ID>
<ADAPTATION_NAME />
<ADAPTATION_VERSION />
<ADAPTATION_PRODUCT_ID />
</info>
<type>
<OBJECT_TYPE>data</OBJECT_TYPE>
<prop>
<DESCRIPTION>Site parameters</DESCRIPTION>
<PARENT>NULL</PARENT>
<VIRTUAL>0</VIRTUAL>
<VISIBLE>1</VISIBLE>
<PICTURE>NULL</PICTURE>
<HELP>10008</HELP>
<MIN_NO>1</MIN_NO>
<MAX_NO>1</MAX_NO>
<NAME_FORMAT>NULL</NAME_FORMAT>
</prop>
<param>
<PARAMETER>nidRbc</PARAMETER>
<DATA_TYPE>INTEGER</DATA_TYPE>
<DESCRIPTION>RBC identity</DESCRIPTION>
<MIN_NO>1</MIN_NO>
<MAX_NO>1</MAX_NO>
<ORDER1>1</ORDER1>
<NESTED>0</NESTED>
<DEFAULT1>NULL</DEFAULT1>
<FORMAT>0:16382</FORMAT>
</param>
</type>
</root>
我最近面臨同樣的問題。 問題是,在xml請求中我沒有給出完整的限定名稱。
<FeatureContextRequest>
<featureRequestType>GLOBAL</featureRequestType>
</FeatureContextRequest>
在意識到這個問題之后,我把它改成了
<com.xxxx.yyyy.services.features.FeatureContextRequest>
<featureRequestType>GLOBAL</featureRequestType>
</com.xxxx.yyyy.services.features.FeatureContextRequest>
從那時起它工作正常。
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