# Java DOM解析器 - 查询XML文档 - Java XML教程
## 演示示例
这是需要我们查询的输入XML文件：
```
Ferarri 101
Ferarri 201
Ferarri 301
Lamborgini 001
Lamborgini 002
Lamborgini 003
Benteley 1
Benteley 2
Benteley 3
```
**演示示例：**
_QueryXmlFileDemo.java_
```
package com.yiibai.xml;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.DocumentBuilder;
import org.w3c.dom.Document;
import org.w3c.dom.NodeList;
import org.w3c.dom.Node;
import org.w3c.dom.Element;
import java.io.File;
public class QueryXmlFileDemo {
public static void main(String argv[]) {
try {
File inputFile = new File("input.txt");
DocumentBuilderFactory dbFactory =
DocumentBuilderFactory.newInstance();
DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();
Document doc = dBuilder.parse(inputFile);
doc.getDocumentElement().normalize();
System.out.print("Root element: ");
System.out.println(doc.getDocumentElement().getNodeName());
NodeList nList = doc.getElementsByTagName("supercars");
System.out.println("----------------------------");
for (int temp = 0; temp < nList.getLength(); temp++) {
Node nNode = nList.item(temp);
System.out.println("\nCurrent Element :");
System.out.print(nNode.getNodeName());
if (nNode.getNodeType() == Node.ELEMENT_NODE) {
Element eElement = (Element) nNode;
System.out.print("company : ");
System.out.println(eElement.getAttribute("company"));
NodeList carNameList =
eElement.getElementsByTagName("carname");
for (int count = 0;
count < carNameList.getLength(); count++) {
Node node1 = carNameList.item(count);
if (node1.getNodeType() ==
node1.ELEMENT_NODE) {
Element car = (Element) node1;
System.out.print("car name : ");
System.out.println(car.getTextContent());
System.out.print("car type : ");
System.out.println(car.getAttribute("type"));
}
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
}
}
```
这将产生以下结果：
```
Root element :cars
----------------------------
Current Element :supercars
company : Ferrari
car name : Ferarri 101
car type : formula one
car name : Ferarri 201
car type : sports car
car name : Ferarri 301
car type : sports car
Current Element :supercars
company : Lamborgini
car name : Lamborgini 001
car type :
car name : Lamborgini 002
car type :
car name : Lamborgini 003
car type :
```