JDOM 供应了异常优异的Java XML API来更轻易的读取、修正、生成XML文档。JDOM还供应了包装类供用户从SAX、DOM、STAX事宜剖析、STAX流剖析中挑选详细的完成。
在本教程中，我们一同进修运用JDOM將读取XML文件信息，并转换为Java对象。
JDOM并不是规范JDK的一部分，因而运用JDOM需要从官方网站中下载JDOM的二进制包，下载后將JDOM的Jar包添加到工程的classpath中即可。
JDOM供应了包装类供我们挑选底层的XML剖析API，它供应了四个主要的类，我们能够运用它猎取JDOM的Document对象。JDOM Document对象供应异常有效的要领来猎取根元素，子元素列表，属性值等。
JDOM的主要的类： org.jdom2.input.DOMBuilder:运用DOM剖析机制剖析XML并将它转换为JDOM Document对象。 org.jdom2.input.SAXBuilder:运用SAX剖析机制剖析XML并转换为JDOM Document。 org.jdom2.input.StAXEventBuilder和org.jdom2.input.StAXStreamBuilder作用和前面两个相似，不再赘述。 org.jdom2.DocumentJDOM Document对象供应有效的要领猎取根元素，读取或修正元素内容等操纵，我们将要运用它猎取XML的根元素。 org.jdom2.Document供应了有效的要领来猎取子元素鸠合，猎取子元素值，猎取属性值等操纵。
接下来我们开始运用案例顺序读取XML文件并生成Java对象。
employees.xml
<?xml version="1.0" encoding="UTF-8"?><Employees>
<Employee id="1">
<age>29</age>
<name>Pankaj</name>
<gender>Male</gender>
<role>Java Developer</role>
</Employee>
<Employee id="2">
<age>35</age>
<name>Lisa</name>
<gender>Female</gender>
<role>CEO</role>
</Employee>
<Employee id="3">
<age>40</age>
<name>Tom</name>
<gender>Male</gender>
<role>Manager</role>
</Employee></Employees>
该xml文件寄存员工信息，我们运用Employee类示意员工。
package com.journaldev.xml;public class Employee {
private int id;
private String name;
private String gender;
private int age;
private String role;
public int getId() {
return id;
} public void setId(int id) {
this.id = id;
} public String getName() {
return name;
} public void setName(String name) {
this.name = name;
} public String getGender() {
return gender;
} public void setGender(String gender) {
this.gender = gender;
} public int getAge() {
return age;
} public void setAge(int age) {
this.age = age;
} public String getRole() {
return role;
} public void setRole(String role) {
this.role = role;
} @Override
public String toString() {
return "Employee:: ID="+this.id+" Name=" + this.name + " Age=" + this.age + " Gender=" + this.gender +
" Role=" + this.role;
}
}
接着在测试顺序中运用DOMBuilder读取XML文件生成Employee对象鸠合。
JDOMXMLReader.java
package com.journaldev.xml.jdom;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.stream.XMLEventReader;
import javax.xml.stream.XMLInputFactory;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamReader;
import org.jdom2.Element;
import org.jdom2.JDOMException;
import org.jdom2.input.DOMBuilder;
import org.jdom2.input.SAXBuilder;
import org.jdom2.input.StAXEventBuilder;
import org.jdom2.input.StAXStreamBuilder;
import org.w3c.dom.Document;
import org.xml.sax.SAXException;
import com.journaldev.xml.Employee;
public class JDOMXMLReader {
public static void main(String[] args) {
final String fileName = "/Users/pankaj/employees.xml";
org.jdom2.Document jdomDoc;
try {
//we can create JDOM Document from DOM, SAX and STAX Parser Builder classes
jdomDoc = useDOMParser(fileName);
Element root = jdomDoc.getRootElement();
List<Element> empListElements = root.getChildren("Employee");
List<Employee> empList = new ArrayList<>();
for (Element empElement : empListElements) {
Employee emp = new Employee();
emp.setId(Integer.parseInt(empElement.getAttributeValue("id")));
emp.setAge(Integer.parseInt(empElement.getChildText("age")));
emp.setName(empElement.getChildText("name"));
emp.setRole(empElement.getChildText("role"));
emp.setGender(empElement.getChildText("gender"));
empList.add(emp);
}
//lets print Employees list information
for (Employee emp : empList)
System.out.println(emp);
} catch (Exception e) {
e.printStackTrace();
}
}
//Get JDOM document from DOM Parser
private static org.jdom2.Document useDOMParser(String fileName)
throws ParserConfigurationException, SAXException, IOException {
//creating DOM Document
DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder dBuilder;
dBuilder = dbFactory.newDocumentBuilder();
Document doc = dBuilder.parse(new File(fileName));
DOMBuilder domBuilder = new DOMBuilder();
return domBuilder.build(doc);
}
}
如你所见，这里我运用DOM剖析包装类猎取JDOM Document对象。
运转顺序输出：
Employee:: ID=1 Name=Pankaj Age=29 Gender=Male Role=Java DeveloperEmployee:: ID=2 Name=Lisa Age=35 Gender=Female Role=CEOEmployee:: ID=3 Name=Tom Age=40 Gender=Male Role=Manager
我们一样能够运用SAX和STAX剖析机制来完成，我们能够运用下面要领完成：
/Get JDOM document from SAX Parserprivate static org.jdom2.Document useSAXParser(String fileName) throws JDOMException,
IOException {
SAXBuilder saxBuilder = new SAXBuilder();
return saxBuilder.build(new File(fileName));
}
//Get JDOM Document from STAX Stream Parser or STAX Event Parserprivate static org.jdom2.
Document useSTAXParser(String fileName, String type) throws FileNotFoundException, XMLStreamException, JDOMException{
if(type.equalsIgnoreCase("stream")){
StAXStreamBuilder staxBuilder = new StAXStreamBuilder();
XMLInputFactory xmlInputFactory = XMLInputFactory.newInstance();
XMLStreamReader xmlStreamReader = xmlInputFactory.createXMLStreamReader(new FileInputStream(fileName));
return staxBuilder.build(xmlStreamReader);
}
StAXEventBuilder staxBuilder = new StAXEventBuilder();
XMLInputFactory xmlInputFactory = XMLInputFactory.newInstance();
XMLEventReader xmlEventReader = xmlInputFactory.createXMLEventReader(new FileInputStream(fileName));
return staxBuilder.build(xmlEventReader);
}
运转顺序将会获得雷同的输出，由于我们只是运用差别的包装类，然则猎取的JDOM Document对象雷同。
运用JDOM的优点是我们能够很轻易的切换底层的剖析机制而处置惩罚代码不发生转变。
JDOM 供应了异常优异的Java XML API来更轻易的读取、修正、生成XML文档。JDOM还供应了包装类供用户从SAX、DOM、STAX事宜剖析、STAX流剖析中挑选详细的完成。
在本教程中，我们一同进修运用JDOM將读取XML文件信息，并转换为Java对象。
JDOM并不是规范JDK的一部分，因而运用JDOM需要从官方网站中下载JDOM的二进制包，下载后將JDOM的Jar包添加到工程的classpath中即可。
JDOM供应了包装类供我们挑选底层的XML剖析API，它供应了四个主要的类，我们能够运用它猎取JDOM的Document对象。JDOM Document对象供应异常有效的要领来猎取根元素，子元素列表，属性值等。
JDOM的主要的类： org.jdom2.input.DOMBuilder:运用DOM剖析机制剖析XML并将它转换为JDOM Document对象。 org.jdom2.input.SAXBuilder:运用SAX剖析机制剖析XML并转换为JDOM Document。 org.jdom2.input.StAXEventBuilder和org.jdom2.input.StAXStreamBuilder作用和前面两个相似，不再赘述。 org.jdom2.DocumentJDOM Document对象供应有效的要领猎取根元素，读取或修正元素内容等操纵，我们将要运用它猎取XML的根元素。 org.jdom2.Document供应了有效的要领来猎取子元素鸠合，猎取子元素值，猎取属性值等操纵。
接下来我们开始运用案例顺序读取XML文件并生成Java对象。
employees.xml
<?xml version="1.0" encoding="UTF-8"?><Employees>
<Employee id="1">
<age>29</age>
<name>Pankaj</name>
<gender>Male</gender>
<role>Java Developer</role>
</Employee>
<Employee id="2">
<age>35</age>
<name>Lisa</name>
<gender>Female</gender>
<role>CEO</role>
</Employee>
<Employee id="3">
<age>40</age>
<name>Tom</name>
<gender>Male</gender>
<role>Manager</role>
</Employee></Employees>
该xml文件寄存员工信息，我们运用Employee类示意员工。
package com.journaldev.xml;
public class Employee {
private int id;
private String name;
private String gender;
private int age;
private String role;
public int getId() {
return id;
} public void setId(int id) {
this.id = id;
} public String getName() {
return name;
} public void setName(String name) {
this.name = name;
} public String getGender() {
return gender;
} public void setGender(String gender) {
this.gender = gender;
} public int getAge() {
return age;
} public void setAge(int age) {
this.age = age;
} public String getRole() {
return role;
} public void setRole(String role) {
this.role = role;
} @Override
public String toString() {
return "Employee:: ID="+this.id+" Name=" + this.name + " Age=" + this.age + " Gender=" + this.gender +
" Role=" + this.role;
}
}
接着在测试顺序中运用DOMBuilder读取XML文件生成Employee对象鸠合。
JDOMXMLReader.java
package com.journaldev.xml.jdom;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;import java.util.ArrayList;
import java.util.List;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.stream.XMLEventReader;
import javax.xml.stream.XMLInputFactory;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamReader;
import org.jdom2.Element;import org.jdom2.JDOMException;
import org.jdom2.input.DOMBuilder;
import org.jdom2.input.SAXBuilder;
import org.jdom2.input.StAXEventBuilder;
import org.jdom2.input.StAXStreamBuilder;
import org.w3c.dom.Document;
import org.xml.sax.SAXException;
import com.journaldev.xml.Employee;
public class JDOMXMLReader {
public static void main(String[] args) {
final String fileName = "/Users/pankaj/employees.xml";
org.jdom2.Document jdomDoc;
try {
//we can create JDOM Document from DOM, SAX and STAX Parser Builder classes
jdomDoc = useDOMParser(fileName);
Element root = jdomDoc.getRootElement();
List<Element> empListElements = root.getChildren("Employee");
List<Employee> empList = new ArrayList<>();
for (Element empElement : empListElements) {
Employee emp = new Employee();
emp.setId(Integer.parseInt(empElement.getAttributeValue("id")));
emp.setAge(Integer.parseInt(empElement.getChildText("age")));
emp.setName(empElement.getChildText("name"));
emp.setRole(empElement.getChildText("role"));
emp.setGender(empElement.getChildText("gender"));
empList.add(emp);
}
//lets print Employees list information
for (Employee emp : empList)
System.out.println(emp);
} catch (Exception e) {
e.printStackTrace();
}
}
//Get JDOM document from DOM Parser
private static org.jdom2.Document useDOMParser(String fileName)
throws ParserConfigurationException, SAXException, IOException {
//creating DOM Document
DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder dBuilder;
dBuilder = dbFactory.newDocumentBuilder();
Document doc = dBuilder.parse(new File(fileName));
DOMBuilder domBuilder = new DOMBuilder();
return domBuilder.build(doc);
}
}
如你所见，这里我运用DOM剖析包装类猎取JDOM Document对象。
运转顺序输出：
Employee:: ID=1 Name=Pankaj Age=29 Gender=Male Role=Java DeveloperEmployee:: ID=2 Name=Lisa Age=35 Gender=Female Role=CEOEmployee:: ID=3 Name=Tom Age=40 Gender=Male Role=Manager
我们一样能够运用SAX和STAX剖析机制来完成，我们能够运用下面要领完成：
/Get JDOM document from SAX Parserprivate static org.jdom2.Document useSAXParser(String fileName) throws JDOMException,
IOException {
SAXBuilder saxBuilder = new SAXBuilder(); return saxBuilder.build(new File(fileName));
}
//Get JDOM Document from STAX Stream Parser or STAX Event Parserprivate static org.jdom2.Document
useSTAXParser(String fileName, String type) throws FileNotFoundException, XMLStreamException, JDOMException{
if(type.equalsIgnoreCase("stream")){
StAXStreamBuilder staxBuilder = new StAXStreamBuilder();
XMLInputFactory xmlInputFactory = XMLInputFactory.newInstance();
XMLStreamReader xmlStreamReader = xmlInputFactory.createXMLStreamReader(new FileInputStream(fileName));
return staxBuilder.build(xmlStreamReader);
}
StAXEventBuilder staxBuilder = new StAXEventBuilder();
XMLInputFactory xmlInputFactory = XMLInputFactory.newInstance();
XMLEventReader xmlEventReader = xmlInputFactory.createXMLEventReader(new FileInputStream(fileName));
return staxBuilder.build(xmlEventReader);
}
运转顺序将会获得雷同的输出，由于我们只是运用差别的包装类，然则猎取的JDOM Document对象雷同。
运用JDOM的优点是我们能够很轻易的切换底层的剖析机制而处置惩罚代码不发生转变。
以上就是Java&Xml教程（六）运用JDOM剖析XML文件的内容，更多相关内容请关注ki4网（www.ki4.cn）！
