我很难得到一些特定的元素，我有一个xml文件，它有根节点“问题”，其中包含子“解决方案”。在解决方案中我有标签名称“cost”，其值为505.9208295302417，我想得到这个孩子的所有元素包含505.9208295302417。到目前为止，我所做的就是所有节点，我只想要这个特定孩子的元素而不是另一个。下面是xml和java代码。
<problem>
<solution>
<cost>505.9214355631349</cost>
<routes>
<route>
<driverId>noDriver</driverId>
<vehicleId>1_1</vehicleId>
<start>0.0</start>
<act type="service">
<serviceId>5 </serviceId>
<arrTime>109.9819741964403</arrTime>
<endTime>119.9819741964403</endTime>
</act>
<end>229.9639483928806</end>
</route>
<route>
<driverId>noDriver</driverId>
<vehicleId>3_1</vehicleId>
<start>0.0</start>
<act type="service">
<serviceId>2 </serviceId>
<arrTime>109.98268205388193</arrTime>
<endTime>119.98268205388193</endTime>
</act>
<act type="service">
<serviceId>1 </serviceId>
<arrTime>119.98357684436793</arrTime>
<endTime>129.98357684436792</endTime>
</act>
<act type="service">
<serviceId>3 </serviceId>
<arrTime>129.98449911991617</arrTime>
<endTime>139.98449911991617</endTime>
</act>
<act type="service">
<serviceId>4 </serviceId>
<arrTime>139.98539391040217</arrTime>
<endTime>149.98539391040217</endTime>
</act>
<end>259.9672978232725</end>
</route>
</routes>
</solution>
<solution>
<cost>505.9208295302417</cost>
<routes>
<route>
<driverId>noDriver</driverId>
<vehicleId>1_1</vehicleId>
<start>0.0</start>
<act type="service">
<serviceId>5 </serviceId>
<arrTime>109.9819741964403</arrTime>
<endTime>119.9819741964403</endTime>
</act>
<end>229.9639483928806</end>
</route>
<route>
<driverId>noDriver</driverId>
<vehicleId>3_1</vehicleId>
<start>0.0</start>
<act type="service">
<serviceId>4 </serviceId>
<arrTime>109.98190391287031</arrTime>
<endTime>119.98190391287031</endTime>
</act>
<act type="service">
<serviceId>2 </serviceId>
<arrTime>119.98282618841856</arrTime>
<endTime>129.98282618841856</endTime>
</act>
<act type="service">
<serviceId>1 </serviceId>
<arrTime>129.98372097890456</arrTime>
<endTime>139.98372097890456</endTime>
</act>
<act type="service">
<serviceId>3 </serviceId>
<arrTime>139.9846432544528</arrTime>
<endTime>149.9846432544528</endTime>
</act>
<end>259.9668316441239</end>
</route>
</routes>
</solution>
</problem>for (int temp = 0; temp < nList.getLength(); temp++) {
Node nNode = nList.item(temp);
System.out.println("\nCurrent Element :" + nNode.getNodeName());
if (nNode.getNodeType() == Node.ELEMENT_NODE) {
Element eElement = (Element) nNode;
//System.out.println("route : "
// + eElement.getAttribute("id"));
System.out.println("DriverId : "
+ eElement.getElementsByTagName("driverId")
.item(0).getTextContent());
System.out.println("vehicleId : "
+ eElement.getElementsByTagName("vehicleId")
.item(0).getTextContent());
NodeList optionList = eElement.getElementsByTagName("act");
for (int j = 0; j < optionList.getLength(); ++j)
{
Element option = (Element) optionList.item(j);
for(int k =0;k<1;++k){
String optionText = option.getTextContent();
address.add(optionText.replaceAll("[^A-Za-z]"," "));
System.out.println("Citizen :"+optionText.replaceAll("[^A-Za-z]"," "));}
;
}
System.out.println("cost : "
+ eElement.getElementsByTagName("end")
.item(0).getTextContent());
}
}
} catch (Exception e) {
e.printStackTrace();
}
***更新***在这里我设法得到我想要的，但有一个概率，对于市民我只有第一个“行为”标签，我需要得到所有的标签价值
import java.io.File;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
/**
*
* @author HP
*/
public class JavaApplication39 {
/**
* @param args the command line arguments
*/
public static void main(String[] args) {
try {
int totalVehicle;
totalVehicle = 2;
File fXmlFile = new File("C:/Users/HP/Desktop/solution.xml");
DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();
Document doc = dBuilder.parse(fXmlFile);
doc.getDocumentElement().normalize();
Double requiredCost = 505.9208295302417;
System.out.println("Root element :" + doc.getDocumentElement().getNodeName());
// NodeList nList = doc.getElementsByTagName("route");
System.out.println("----------------------------");
NodeList nodeList = doc.getElementsByTagName("solution");
for (int i = 0; i < nodeList.getLength(); i++) {
Node solutionNode = nodeList.item(i);
if (solutionNode.getNodeType() == Node.ELEMENT_NODE) {
Element solutionElement = (Element) solutionNode;
Node costNode = solutionElement.getElementsByTagName("cost").item(0);
Node route = solutionElement.getElementsByTagName("routes").item(0);
// if correct cost, proceed to parse further
Double costValue = Double.valueOf(costNode.getTextContent());
if (Double.compare(requiredCost, costValue) == 0) {
System.out.println("working");
// there you go, found the node with the cost 505.9208295302417
// now just parse all the node elements you need here
System.out.println("cost : "
+ solutionElement.getElementsByTagName("cost")
.item(0).getTextContent());
for (int h = 0; h < totalVehicle; h++) {
System.out.println("DriverId : "
+ solutionElement.getElementsByTagName("driverId")
.item(h).getTextContent().toString());
System.out.println("vehicleId : "
+ solutionElement.getElementsByTagName("vehicleId")
.item(h).getTextContent());
System.out.println("citizen: "
+ solutionElement.getElementsByTagName("act")
.item(h).getTextContent());
}
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
//System.out.println(address.get(1));
}
}
只是我或我在你的代码中没有看到任何比较？检查节点是否有您需要的费用？您可以循环遍历解决方案节点（正如您所做的那样），一旦找到正确的成本值，就可以从该节点解析所需的所有元素。
示例代码：
NodeList nodeList = doc.getElementsByTagName("solution");
Double requiredCost = 505.9208295302417;
for (int i = 0; i < nodeList.getLength(); i++) {
Node solutionNode = nodeList.item(i);
if (solutionNode.getNodeType() == Node.ELEMENT_NODE) {
Element solutionElement = (Element) solutionNode;
Node costNode = solutionElement.getElementsByTagName("cost").item(0);
// if correct cost, proceed to parse further
Double costValue = Double.valueOf(costNode.getTextContent());
if (Double.compare(requiredCost, costValue) == 0) {
// there you go, found the node with the cost 505.9208295302417
// now just parse all the node elements you need here
}
}
}