【发布时间】：2017-02-23 07:18:09
【问题描述】：
所以在寻找解决方案here、here 和here 之后，我仍然无法从XML 中解析Java 对象。 XML 有嵌套标签，我已经相应地设计了我的类，但我不知道哪里出错了。
以下是我的 XML
private static final String XML = "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n" +
"<author>\n" +
"<name>Auro</name>\n" +
"<id>123</id>\n" +
"<books>\n" +
"<name>C++</name>\n" +
"<status>published</status>\n" +
"</books>\n" +
"<books>\n" +
"<name>Java</name>\n" +
"<status>unpublished</status>\n" +
"</books>\n" +
"</author>";
作者类
public class Author {
private String name;
private String id;
private List<Books> books;
public Author() {}
public Author(String name, String id, List<Books> books) {
this.name = name;
this.id = id;
this.books = books;
}
// Getters
public String getName() {
return name;
}
public String getId() {
return id;
}
public List<Books> getBooks() {
return books;
}
// Setters
public void setName(String name) {
this.name = name;
}
public void setId(String id) {
this.id = id;
}
public void setBooks(List<Books> books) {
this.books = books;
}
public String toString() {
String res = "Author_Name: " + name + " -- " + "Author_ID: " + id + " ";
for (Books book : books) {
res = res + book.toString();
}
return res;
}
}
Books.java 类
public class Books {
private String name;
private String status;
public Books() {}
public Books(String name, String status) {
this.name = name;
this.status = status;
}
// Getters
public String getName() {
return name;
}
public String getStatus() {
return status;
}
// Setters
public void setName(String name) {
this.name = name;
}
public void setStatus(String status) {
this.status = status;
}
public String toString() {
return "Book_Name: " + name + " -- " + "Book_Status: " + status + "\n";
}
}
以下是我调用方法的方式
@RequestMapping(value = "/parse", method = RequestMethod.GET)
public String parse() {
System.out.print("THIS GOT TRIGGERED!!");
XStream xStream = new XStream();
xStream.alias("author",Author.class);
xStream.alias("books",Books.class);
Author author = (Author) xStream.fromXML(XML);
System.out.print(author.toString());
return author.toString();
}
但我的应用程序因以下错误而崩溃：
-- Debugging information ----
cause-exception : com.thoughtworks.xstream.mapper.CannotResolveClassException
cause-message : name
class : java.util.ArrayList
required-type : java.util.ArrayList
converter-type : com.thoughtworks.xstream.converters.collections.CollectionConverter
path : /author/books/name
line number : 6
class[1] : blahblah.testSpringboot.models.Author
converter-type[1] : com.thoughtworks.xstream.converters.reflection.ReflectionConverter
version : 1.4.9
-------------------------------] with root cause
com.thoughtworks.xstream.mapper.CannotResolveClassException: name
at com.thoughtworks.xstream.mapper.DefaultMapper.realClass(DefaultMapper.java:81) ~[xstream-1.4.9.jar:1.4.9]
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30) ~[xstream-1.4.9.jar:1.4.9]
at com.thoughtworks.xstream.mapper.DynamicProxyMapper.realClass(DynamicProxyMapper.java:55) ~[xstream-1.4.9.jar:1.4.9]
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30) ~[xstream-1.4.9.jar:1.4.9]
at com.thoughtworks.xstream.mapper.PackageAliasingMapper.realClass(PackageAliasingMapper.java:88) ~[xstream-1.4.9.jar:1.4.9]
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30) ~[xstream-1.4.9.jar:1.4.9]
at com.thoughtworks.xstream.mapper.ClassAliasingMapper.realClass(ClassAliasingMapper.java:79) ~[xstream-1.4.9.jar:1.4.9]
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30) ~[xstream-1.4.9.jar:1.4.9]
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30) ~[xstream-1.4.9.jar:1.4.9]
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30) ~[xstream-1.4.9.jar:1.4.9]
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30) ~[xstream-1.4.9.jar:1.4.9]
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30) ~[xstream-1.4.9.jar:1.4.9]
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30) ~[xstream-1.4.9.jar:1.4.9]
at com.thoughtworks.xstream.mapper.ArrayMapper.realClass(ArrayMapper.java:74) ~[xstream-1.4.9.jar:1.4.9]
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30) ~[xstream-1.4.9.jar:1.4.9]
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30) ~[xstream-1.4.9.jar:1.4.9]
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30) ~[xstream-1.4.9.jar:1.4.9]
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30) ~[xstream-1.4.9.jar:1.4.9]
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30) ~[xstream-1.4.9.jar:1.4.9]
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30) ~[xstream-1.4.9.jar:1.4.9]
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30) ~[xstream-1.4.9.jar:1.4.9]
at com.thoughtworks.xstream.mapper.SecurityMapper.realClass(SecurityMapper.java:71) ~[xstream-1.4.9.jar:1.4.9]
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30) ~[xstream-1.4.9.jar:1.4.9]
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30) ~[xstream-1.4.9.jar:1.4.9]
at com.thoughtworks.xstream.mapper.CachingMapper.realClass(CachingMapper.java:47) ~[xstream-1.4.9.jar:1.4.9]
at com.thoughtworks.xstream.core.util.HierarchicalStreams.readClassType(HierarchicalStreams.java:29) ~[xstream-1.4.9.jar:1.4.9]
at com.thoughtworks.xstream.converters.collections.AbstractCollectionConverter.readItem(AbstractCollectionConverter.java:72) ~[xstream-1.4.9.jar:1.4.9]
at com.thoughtworks.xstream.converters.collections.CollectionConverter.addCurrentElementToCollection(CollectionConverter.java:98) ~[xstream-1.4.9.jar:1.4.9]
at com.thoughtworks.xstream.converters.collections.CollectionConverter.populateCollection(CollectionConverter.java:91) ~[xstream-1.4.9.jar:1.4.9]
at com.thoughtworks.xstream.converters.collections.CollectionConverter.populateCollection(CollectionConverter.java:85) ~[xstream-1.4.9.jar:1.4.9]
at com.thoughtworks.xstream.converters.collections.CollectionConverter.unmarshal(CollectionConverter.java:80) ~[xstream-1.4.9.jar:1.4.9]
at com.thoughtworks.xstream.core.TreeUnmarshaller.convert(TreeUnmarshaller.java:72) ~[xstream-1.4.9.jar:1.4.9]
at com.thoughtworks.xstream.core.AbstractReferenceUnmarshaller.convert(AbstractReferenceUnmarshaller.java:70) ~[xstream-1.4.9.jar:1.4.9]
at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:66) ~[xstream-1.4.9.jar:1.4.9]
at com.thoughtworks.xstream.converters.reflection.AbstractReflectionConverter.unmarshallField(AbstractReflectionConverter.java:503) ~[xstream-1.4.9.jar:1.4.9]
at com.thoughtworks.xstream.converters.reflection.AbstractReflectionConverter.doUnmarshal(AbstractReflectionConverter.java:429) ~[xstream-1.4.9.jar:1.4.9]
at com.thoughtworks.xstream.converters.reflection.AbstractReflectionConverter.unmarshal(AbstractReflectionConverter.java:281) ~[xstream-1.4.9.jar:1.4.9]
at com.thoughtworks.xstream.core.TreeUnmarshaller.convert(TreeUnmarshaller.java:72) ~[xstream-1.4.9.jar:1.4.9]
at com.thoughtworks.xstream.core.AbstractReferenceUnmarshaller.convert(AbstractReferenceUnmarshaller.java:70) ~[xstream-1.4.9.jar:1.4.9]
at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:66) ~[xstream-1.4.9.jar:1.4.9]
at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:50) ~[xstream-1.4.9.jar:1.4.9]
at com.thoughtworks.xstream.core.TreeUnmarshaller.start(TreeUnmarshaller.java:134) ~[xstream-1.4.9.jar:1.4.9]
at com.thoughtworks.xstream.core.AbstractTreeMarshallingStrategy.unmarshal(AbstractTreeMarshallingStrategy.java:32) ~[xstream-1.4.9.jar:1.4.9]
at com.thoughtworks.xstream.XStream.unmarshal(XStream.java:1230) ~[xstream-1.4.9.jar:1.4.9]
at com.thoughtworks.xstream.XStream.unmarshal(XStream.java:1214) ~[xstream-1.4.9.jar:1.4.9]
at com.thoughtworks.xstream.XStream.fromXML(XStream.java:1085) ~[xstream-1.4.9.jar:1.4.9]
at com.thoughtworks.xstream.XStream.fromXML(XStream.java:1076) ~[xstream-1.4.9.jar:1.4.9]
at blahblah.testSpringboot.controllers.TestParser.parse(TestParser.java:39) ~[classes/:na]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_112]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_112]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_112]
at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_112]
at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:205) ~[spring-web-4.3.6.RELEASE.jar:4.3.6.RELEASE]
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:133) ~[spring-web-4.3.6.RELEASE.jar:4.3.6.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:116) ~[spring-webmvc-4.3.6.RELEASE.jar:4.3.6.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827) ~[spring-webmvc-4.3.6.RELEASE.jar:4.3.6.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738) ~[spring-webmvc-4.3.6.RELEASE.jar:4.3.6.RELEASE]
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85) ~[spring-webmvc-4.3.6.RELEASE.jar:4.3.6.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:963) ~[spring-webmvc-4.3.6.RELEASE.jar:4.3.6.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:897) ~[spring-webmvc-4.3.6.RELEASE.jar:4.3.6.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970) ~[spring-webmvc-4.3.6.RELEASE.jar:4.3.6.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:861) ~[spring-webmvc-4.3.6.RELEASE.jar:4.3.6.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:622) ~[tomcat-embed-core-8.5.11.jar:8.5.11]
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846) ~[spring-webmvc-4.3.6.RELEASE.jar:4.3.6.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729) ~[tomcat-embed-core-8.5.11.jar:8.5.11]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:230) ~[tomcat-embed-core-8.5.11.jar:8.5.11]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165) ~[tomcat-embed-core-8.5.11.jar:8.5.11]
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) ~[tomcat-embed-websocket-8.5.11.jar:8.5.11]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192) ~[tomcat-embed-core-8.5.11.jar:8.5.11]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165) ~[tomcat-embed-core-8.5.11.jar:8.5.11]
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99) ~[spring-web-4.3.6.RELEASE.jar:4.3.6.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.6.RELEASE.jar:4.3.6.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192) ~[tomcat-embed-core-8.5.11.jar:8.5.11]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165) ~[tomcat-embed-core-8.5.11.jar:8.5.11]
at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:105) ~[spring-web-4.3.6.RELEASE.jar:4.3.6.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.6.RELEASE.jar:4.3.6.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192) ~[tomcat-embed-core-8.5.11.jar:8.5.11]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165) ~[tomcat-embed-core-8.5.11.jar:8.5.11]
at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:81) ~[spring-web-4.3.6.RELEASE.jar:4.3.6.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.6.RELEASE.jar:4.3.6.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192) ~[tomcat-embed-core-8.5.11.jar:8.5.11]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165) ~[tomcat-embed-core-8.5.11.jar:8.5.11]
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197) ~[spring-web-4.3.6.RELEASE.jar:4.3.6.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.6.RELEASE.jar:4.3.6.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192) ~[tomcat-embed-core-8.5.11.jar:8.5.11]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165) ~[tomcat-embed-core-8.5.11.jar:8.5.11]
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198) ~[tomcat-embed-core-8.5.11.jar:8.5.11]
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-8.5.11.jar:8.5.11]
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:474) [tomcat-embed-core-8.5.11.jar:8.5.11]
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140) [tomcat-embed-core-8.5.11.jar:8.5.11]
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79) [tomcat-embed-core-8.5.11.jar:8.5.11]
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87) [tomcat-embed-core-8.5.11.jar:8.5.11]
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:349) [tomcat-embed-core-8.5.11.jar:8.5.11]
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:783) [tomcat-embed-core-8.5.11.jar:8.5.11]
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) [tomcat-embed-core-8.5.11.jar:8.5.11]
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:798) [tomcat-embed-core-8.5.11.jar:8.5.11]
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1434) [tomcat-embed-core-8.5.11.jar:8.5.11]
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-8.5.11.jar:8.5.11]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [na:1.8.0_112]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [na:1.8.0_112]
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-8.5.11.jar:8.5.11]
at java.lang.Thread.run(Thread.java:745) [na:1.8.0_112]
我不知道我哪里错了。是我的 XML 还是我的方法中遗漏的东西？
【问题讨论】：