将XML转换为Java Map< String，Integer>与XStream [英] Converting XML to Java Map<String, Integer> with XStream

问题描述

我正在使用XStream将XML转换为Java Map。每次我解决一个问题，我遇到了另一个问题。令人难以置信的令人沮丧无论如何，XML看起来像这样：

 <？xml version =1.0encoding =UTF-8？ > 
< root> 
< Durapipe type =int> 1< / Durapipe> 
< EXPLAIN type =int> 2< / EXPLAIN> 
< woods type =int> 2< / woods> 
< hang type =int> 3< / hang> 
< hastily type =int> 2< / hastily> 
< localized type =int> 1< / localized> 
< Schuster type =int> 5< / Schuster> 
 .... 
< / root> 
  

我用于实现的主要Java类似于：

  XStream xstream = new XStream（）; 
 Map< String，Integer> englishCorpusProbDist; 
 xstream.registerConverter（new MapEntryConverter（））; 
 englishCorpusProbDist =（Map< String，Integer>）xstream.fromXML（new File（locationOnMyComputer / frequencies.xml））; 
  

我创建的MapEntryConverter类如下所示：

  public class MapEntryConverter implements Converter {
 public class java {
 
} 
 
 public boolean canConvert Class clazz）{
 return Map.class.isAssignableFrom（clazz）; 
} 
 
 public void marshal（Object value，HierarchicalStreamWriter writer，MarshallingContext context）{
 Map< String，Integer> map =（Map< String，Integer>）value; $（$）
 for（Map.Entry< String，Integer>条目：map.entrySet（））{
 writer.startNode（entry.getKey（）。toString（））; 
 writer.setValue（entry.getValue（）。toString（））; 
 writer.endNode（）; 
} 
} 
 
 public Object unmarshal（HierarchicalStreamReader reader，UnmarshallingContext context）{
 Map< String，Integer> map = new HashMap< String，Integer>（）; 
 
 while（reader.hasMoreChildren（））{
 reader.moveDown（）; 
 map.put（reader.getNodeName（），new Integer（reader.getValue（）））; 
 reader.moveUp（）; 
} 
返回地图; 
} 
} 
  

目前我收到以下异常： 线程中的异常maincom.thoughtworks.xstream.mapper.CannotResolveClassException：root。

任何人都可以解释为什么会这样，我该如何解决这个问题？ p>

这个问题似乎可能有答案，但我认为我们正在使用不同的实现： com.thoughtworks.xstream.mapper.CannotResolveClassException

任何帮助将不胜感激。感谢提前！

解决方案

尝试这样：

  XStream xstream = new XStream（new DomDriver（））; 
 xstream.alias（root，Map.class）; 
 Map< String，Integer> englishCorpusProbDist; 
 xstream.registerConverter（new MapEntryConverter（））; 
 englishCorpusProbDist =（Map< String，Integer>）xstream.fromXML（new FileInputStream（new File（locationOnMyComputer / frequencies.xml）））; 
  

I'm converting XML to a Java Map with XStream. Each time I solve one problem, I run into another. Incredibly frustrating. Anyways, the XML looks something like this:

<?xml version="1.0" encoding="UTF-8" ?>
    <root>
        <Durapipe type="int">1</Durapipe>
        <EXPLAIN type="int">2</EXPLAIN>
        <woods type="int">2</woods>
        <hanging type="int">3</hanging>
        <hastily type="int">2</hastily>
        <localized type="int">1</localized>
        <Schuster type="int">5</Schuster>
        ....
    </root>

The Java in my main that I'm using to implement this looks like this:

XStream xstream = new XStream();
    Map<String, Integer> englishCorpusProbDist; 
    xstream.registerConverter(new MapEntryConverter());
    englishCorpusProbDist = (Map<String, Integer>)xstream.fromXML(new File("locationOnMyComputer/frequencies.xml"));

The MapEntryConverter class that I've created looks like this:

public class MapEntryConverter implements Converter {
  public class java {

    }

public boolean canConvert(Class clazz) {
    return Map.class.isAssignableFrom(clazz);
  }

  public void marshal(Object value, HierarchicalStreamWriter writer, MarshallingContext context) {
    Map<String, Integer> map = (Map<String, Integer>) value;
    for (Map.Entry<String, Integer> entry : map.entrySet()) {
      writer.startNode(entry.getKey().toString());
      writer.setValue(entry.getValue().toString());
      writer.endNode();
    }
  }

  public Object unmarshal(HierarchicalStreamReader reader, UnmarshallingContext context) {
    Map<String, Integer> map = new HashMap<String, Integer>();

    while (reader.hasMoreChildren()) {
      reader.moveDown();
      map.put(reader.getNodeName(), new Integer(reader.getValue()));
      reader.moveUp();
    }
    return map;
  }
}

At the moment I'm getting the following exception: "Exception in thread "main" com.thoughtworks.xstream.mapper.CannotResolveClassException: root".

Can anyone explain why this is and how I could fix this?

This question seemed like it might have the answer, but I think we're using different implementations: com.thoughtworks.xstream.mapper.CannotResolveClassException

Any help would be greatly appreciated. Thanks in advance!

解决方案

Try this:

XStream xstream = new XStream(new DomDriver());
        xstream.alias("root", Map.class);
        Map<String, Integer> englishCorpusProbDist; 
        xstream.registerConverter(new MapEntryConverter());
        englishCorpusProbDist = (Map<String, Integer>)xstream.fromXML(new FileInputStream(new File("locationOnMyComputer/frequencies.xml")));

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