使用dom4j的

Question

在XML相同水平的運動元素我有下面的XML：

<Vehicle xmlns="http://www.cartest.co.uk"> 
    <Car> 
    <EngineSize>2100</EngineSize> 
    <Color>Green</Color> 
    <NoOfDoors>5</NoOfDoors> 
    <MaxSpeed>150</MaxSpeed> 
    <Interior>Leather</Interior> 
    </Car> 
    <Car> 
    <EngineSize>1000</EngineSize> 
    <Color>Red</Color> 
    <NoOfDoors>3</NoOfDoors> 
    <MaxSpeed>120</MaxSpeed> 
    <Interior>Leather</Interior> 
    </Car> 
    <Car> 
    <EngineSize>1400</EngineSize> 
    <Color>Blue</Color> 
    <MaxSpeed>100</MaxSpeed> 
    <Interior>Fabric</Interior> 
    </Car> 
</Vehicle> 

我想要做的就是解析文檔，如果NoOfDoors元素存在，將它上面的MAXSPEED元素。

所以採取上述示例XML，我會得到下面的輸出：

<Vehicle xmlns="http://www.cartest.co.uk"> 
    <Car> 
    <EngineSize>2100</EngineSize> 
    <Color>Green</Color> 
    <MaxSpeed>150</MaxSpeed> 
    <NoOfDoors>5</NoOfDoors> 
    <Interior>Leather</Interior> 
    </Car> 
    <Car> 
    <EngineSize>1000</EngineSize> 
    <Color>Red</Color> 
    <MaxSpeed>120</MaxSpeed> 
    <NoOfDoors>3</NoOfDoors> 
    <Interior>Leather</Interior> 
    </Car> 
    <Car> 
    <EngineSize>1400</EngineSize> 
    <Color>Blue</Color> 
    <MaxSpeed>100</MaxSpeed> 
    <Interior>Fabric</Interior> 
    </Car> 
</Vehicle> 

我已經創建了下面的代碼片段（很多其他的嘗試中），我只是不能似乎得到它的工作：

// Parse the XML document 
doc = ParseDocument(fileName); 

// Deal with default namespace 
HashMap map = new HashMap(); 
map.put("ns", "http://www.cartest.co.uk"); 
Dom4jXPath xpath = new Dom4jXPath("//ns:Car"); 
xpath.setNamespaceContext(new SimpleNamespaceContext(map)); 

List<Node> nodes = xpath.selectNodes(doc); 

for(Node node : nodes) 
{ 
    Element element = (Element)node; 
    Iterator<Element> iterator = element.elementIterator(); 

    while(iterator.hasNext()) 
    { 
     Element currentElement = (Element)iterator.next(); 

     if(currentElement.getName().equals("NoOfDoors")) 
     { 
     List<Element> elementList = currentElement.getParent().elements();  

     for(Element elements : elementList) 
     { 
      if(elements.getName().equals("MaxSpeed")) 
      { 
       Node moveNode = elements.detach(); 
       elementList.add(elementList.indexOf(elements), (Element) moveNode); 
      } 
     } 
     } 
    } 
} 

運行時提供了以下錯誤的代碼：

java.lang.IndexOutOfBoundsException: Index: -1 

任意子í知道如何使用Dom4J做到這一點？我似乎遇到的問題是當我分離元素時，我似乎不能將它添加回到我擁有的列表中。

Answer 1

我設法通過創建一個新的列表，然後使用一個新的迭代在這個列表迭代如圖下面的代碼得到這個工作：

// Parse the XML document 
doc = ParseDocument(fileName); 

// Deal with default namespace 
HashMap map = new HashMap(); 
map.put("ns", "http://www.cartest.co.uk"); 
Dom4jXPath xpath = new Dom4jXPath("//ns:Car"); 
xpath.setNamespaceContext(new SimpleNamespaceContext(map)); 

List<Node> nodes = xpath.selectNodes(doc); 

for(Node node : nodes) 
{ 
    Element element = (Element)node; 
    Iterator<Element> iterator = element.elementIterator(); 

    while(iterator.hasNext()) 
    { 
     Element currentElement = (Element)iterator.next(); 

     if(currentElement.getName().equals("NoOfDoors")) 
     { 
     List<Element> elementList = currentElement.getParent().elements();  

     Iterator<Element> iterator2 = element.elementIterator(); 

     while(iterator2.hasNext()) 
     { 

      Element newCurrentElement = (Element)iterator2.next(); 

      if(newCurrentElement.getName().equals("MaxSpeed")) 
      { 
       newCurrentElement.detach(); 
       elementList.add(elementList.indexOf(currentElement), newCurrentElement); 
      } 

     } 
    } 
}