Thực hành sử dụng XML trong Java Lab 4

Processing XML Using Java

Lab 04
StAX and JAXB
Mục tiêu
- Sử dụng XMLStreamReader đọc nội dung XML
- Sử dụng XMLStreamWriter ghi file XML
- Sử dụng XMLEventReader ghi nội dung ra file XML
- Sử dụng JAXB Marshelling chuyển nội dung java object sang file XML
- Sử dụng JAXB UnMarsher lấy nội dung file XML vào java object

Phần I Bài tập step by step
Bài 4.1
Sử dụng XMLStreamReader đọc nội dung file ccinfo.xml:
 ccinfo.xml

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 Output:

Step 1: Tạo project java mới trong netbean
 File  New Project  Java  Java Application
 Project Name: Đặt tên Project là StAX
Step 2: Tạo File ccinfo.xml

 Project  New  Other  XML  XML Document
 ccinfo.xml
<?xml version="1.0" encoding="UTF-8"?>
To change this template file, choose Tools | Templates
and open the template in the editor.
-->
<!-- XML DATA FOR CREDIT CARD INFORMATION -->
<PayInfo>
<Name>David McArthur</Name>
<CreditCard Limit="10,000" Currency="USD">
<Number>9921 5681 2521 8845</Number>

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Processing XML Using Java
<Issuer>CreditBank</Issuer>
<Expiration>06/10</Expiration>
</CreditCard>
</PayInfo>

Step 3: Tạo lớp BKXMLStreamReader để đọc và in nội dụng file ccinfo.xml
 BKXMLStreamReader.java
package stax;
import java.io.File;

import java.io.FileInputStream;
import javax.xml.stream.XMLInputFactory;
import javax.xml.stream.XMLStreamReader;
/**
*
* @author DELL
*/
public class BKXMLStreamReader {
public static void StreamReader(File file) {
try {
//create XML Input Factory
XMLInputFactory inputFactory = XMLInputFactory.newInstance();
//create XML Stream Reader form XMLInputFactory and source file ccinfo.xml
XMLStreamReader streamReader = inputFactory.createXMLStreamReader(new FileInputStream(file));
//Returns type of event an integer
while (streamReader.hasNext()) {
int eventType = streamReader.getEventType();
//check value of each event type
switch (eventType) {
//Event - start Element
case 1:
System.out.println("Event Type - START_ELEMENT(1)");
System.out.println("Start Element Name - " + streamReader.getLocalName());
//Event - end Element
case 2:
System.out.println("Event Type - END_ELEMENT(2)");
System.out.println("End Element Name - " + streamReader.getLocalName());
break;
//Event - Processing Instruction
case 3:

System.out.println("Event Type – PROCESSING_INSTRUCTION(3)");
System.out.println("Processing Instruction Data - " + streamReader.getPIData());
break;
//Event - Character
case 4:
System.out.println("Event Type - CHARACTERS(4)");
System.out.println("Character Data - " + streamReader.getText());
break;
//Event - Comment
case 5:
System.out.println("Event Type - COMMENT(5)");
System.out.println("Comment Data - " + streamReader.getText());

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break;
//Event - Space
case 6:
System.out.println("Event Type - SPACE(6)");
System.out.println("Space Info - " + streamReader.getText());
break;
//Event - Start Document
case 7:
System.out.println("Event Type - START_DOCUMENT(7)");

System.out.println("Character Encoding Scheme - " + streamReader.getCharacterEncodingScheme());
System.out.println("Version - " + streamReader.getVersion());
break;
}
streamReader.next();
}
int eventType = streamReader.getEventType();
//Event - End Document
if (eventType == 8) {
System.out.println("Event Type - END_DOCUMENT(8) - closing document");
streamReader.close();
}
} catch (Exception ex) {
ex.printStackTrace();
}
}
}

Step 4: Triển khai hàm main của ứng dụng

 StAX.java
package stax;
import java.io.File;
/**
*
* @author DELL
*/
public class StAX {
/**
* @param args the command line arguments

*/
public static void main(String[] args) {
try {
//Reader
File file = new File("ccinfo.xml");
BKXMLStreamReader bSR = new BKXMLStreamReader();
bSR.StreamReader(file);
} catch (Exception e) {
e.printStackTrace();
}
}
}

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Step 5: Build and Run ứng dụng

Bài 4.2
Sử dụng XMLStreamWriter Interface để ghi dữ liệu ra file output.xml

Step 1: Tạo lớp BKXMLStreamWriter để ghi dữ liệu ra file xml
 BKXMLStreamWriter.java
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package stax;
import java.io.File;
import java.io.FileWriter;
import javax.xml.stream.XMLOutputFactory;
import javax.xml.stream.XMLStreamWriter;
/**
*
* @author DELL
*/
public class BKXMLStreamWriter {
public static void StreamWriter(File file) {
//create XML Output Factory
XMLOutputFactory factory = XMLOutputFactory.newInstance();
try {
//create XML Stream Writer form XMLOutputFactory and recorded file xml
XMLStreamWriter writer = factory.createXMLStreamWriter(new FileWriter(file));
//Start write Document,Element,Value of Element, Attribute
writer.writeStartDocument("1.0");
writer.writeStartElement("Employees");
writer.writeStartElement("employee");
writer.writeAttribute("id", "111");
writer.writeStartElement("firstName");
writer.writeCharacters("John");
writer.writeEndElement();

writer.writeStartElement("lasttName");
writer.writeCharacters("Peter");
writer.writeEndElement();
writer.writeStartElement("location");
writer.writeCharacters("London");
writer.writeEndElement();
writer.writeEndElement();
writer.writeEndDocument();
writer.flush();
writer.close();
} catch (Exception ex) {
ex.printStackTrace();
}
}
}

Step 2: Triển khai hàm main của ứng dụng
package stax;
import java.io.File;
/**
*
* @author DELL
*/
public class StAX {
/**
* @param args the command line arguments
*/

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public static void main(String[] args) {
try {
//Reader
File file = new File("ccinfo.xml");
BKXMLStreamReader bSR = new BKXMLStreamReader();
//
bSR.StreamReader(file);
//writer
File fileWriter = new File("output.xml");
BKXMLStreamWriter bSW = new BKXMLStreamWriter();
bSW.StreamWriter(fileWriter);
} catch (Exception e) {
e.printStackTrace();
}
}
}

Step 3: Build and Run ứng dụng

Bài 4.3
Sử dụng XMLEventReader và interator để phân tích và in ra nội dung file xml

 Employees.xml

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 Output

Step 1: Tạo lớp BKXMLEventReader để phân tích và in nội dung Employees.xml

 BKXMLEventReader.java
package stax;
import java.io.Reader;
import java.util.Iterator;
import javax.xml.namespace.QName;

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import javax.xml.stream.XMLEventReader;
import javax.xml.stream.XMLInputFactory;
import javax.xml.stream.XMLStreamException;

import javax.xml.stream.events.Attribute;
import javax.xml.stream.events.Characters;
import javax.xml.stream.events.EndElement;
import javax.xml.stream.events.StartElement;
import javax.xml.stream.events.XMLEvent;
/**
*
* @author DELL
*/
public class BKXMLEventReader {
public static void EventReader(Reader fileReader) {
//create XML Input Factory
XMLInputFactory factory = XMLInputFactory.newInstance();
try {
//create XML Event Reader form XMLInputFactory and Reader file
XMLEventReader reader = factory.createXMLEventReader(fileReader);
//loop EventReader
while (reader.hasNext()) {
//get XMLEvent
XMLEvent event = reader.nextEvent();
//Event is start element
if (event.isStartElement()) {
StartElement element = (StartElement) event;
System.out.println("Start Element: " + element.getName());
Iterator iterator = element.getAttributes();
while (iterator.hasNext()) {
Attribute attribute = (Attribute) iterator.next();
QName name = attribute.getName();
String value = attribute.getValue();
System.out.println("Attribute name/value: " + name + "/" + value);

}
}
//Event is end element
if (event.isEndElement()) {
EndElement element = (EndElement) event;
System.out.println("End element:" + element.getName());
}
//Event is character
if (event.isCharacters()) {
Characters characters = (Characters) event;
System.out.println("Text: " + characters.getData());
}
}
} catch (XMLStreamException ex) {
ex.printStackTrace();
}
}
}

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 Cấu trúc project sau khi hoàn thành

Step 2: Triển khai hàm main của ứng dụng

package stax;
import java.io.File;
import java.io.FileReader;
import java.io.Reader;
/**
*
* @author DELL
*/
public class StAX {
/**
* @param args the command line arguments
*/
public static void main(String[] args) {
try {
//Reader
File file = new File("ccinfo.xml");
BKXMLStreamReader bSR = new BKXMLStreamReader();
//
bSR.StreamReader(file);
//writer
File fileWriter = new File("output.xml");
BKXMLStreamWriter bSW = new BKXMLStreamWriter();
//
bSW.StreamWriter(fileWriter);
//EventReader
Reader fileReader = new FileReader(new File("Employees.xml"));
BKXMLEventReader bER = new BKXMLEventReader();
bER.EventReader(fileReader);
} catch (Exception e) {
e.printStackTrace();

}
}
}

Step 3: Build and Run ứng dụng

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Bài 4.4
Sử dụng JAXB để chuyển java object thành file xml

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Step 1: Tạo project java mới trong netbean
 File  New Project  Java  Java Application
 Project Name: Đặt tên Project là JAXB
Step 2: Tạo java object JAXBEmployee được sử dụng để tạo ra file xml

 JAXBEmployee.java
package jaxb;
import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlRootElement;
/**
*
* @author DELL
*/
@XmlRootElement(name="employee")
@XmlAccessorType(XmlAccessType.FIELD)
public class JAXBEmployee {
private Integer id;
private String firstName;
private String lastName;
private double income;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getFirstName() {
return firstName;
}
public void setFirstName(String firstName) {
this.firstName = firstName;
}
public String getLastName() {
return lastName;

}
public void setLastName(String lastName) {
this.lastName = lastName;
}
public double getIncome() {
return income;
}

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public void setIncome(double income) {
this.income = income;
}
}

Step 3: Tạo java object Map
 EmployeeMap.java
package jaxb;
import java.util.HashMap;
import java.util.Map;
import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlRootElement;
/**

*
* @author DELL
*/
@XmlRootElement(name="employees")
@XmlAccessorType(XmlAccessType.FIELD)
public class EmployeeMap
{
private Map<Integer,JAXBEmployee> employeeMap = new HashMap<Integer, JAXBEmployee>();
public Map<Integer, JAXBEmployee> getEmployeeMap() {
return employeeMap;
}
public void setEmployeeMap(Map<Integer, JAXBEmployee> employeeMap) {
this.employeeMap = employeeMap;
}
}

Step 4: Triển khai hàm main của ứng dụng để tạo file JAXBMarshalOutput.xml từ
JAXBEmployee và EmployeeMap
package jaxb;
import java.io.File;
import java.util.HashMap;
import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Marshaller;

/**
*
* @author DELL
*/
public class JAXB {

/**

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* @param args the command line arguments
*/
public static void main(String[] args) {
//create HashMap
HashMap<Integer, JAXBEmployee> map = new HashMap<Integer, JAXBEmployee>();
//create object JAXBEmployee emp1
JAXBEmployee emp1 = new JAXBEmployee();
//Set value to object emp1
emp1.setId(1);
emp1.setFirstName("Allen");
emp1.setLastName("Smith");
emp1.setIncome(100.0);
//create object JAXBEmployee emp2
JAXBEmployee emp2 = new JAXBEmployee();
//Set value to object emp2
emp2.setId(2);
emp2.setFirstName("John");
emp2.setLastName("Mclane");
emp2.setIncome(200.0);
map.put(1, emp1);

map.put(2, emp2);
//add employee in map
EmployeeMap employeeMap = new EmployeeMap();
employeeMap.setEmployeeMap(map);
try {
//create JAXB context and instantiate marshaller
JAXBContext jaxbContext = JAXBContext.newInstance(EmployeeMap.class);
Marshaller jaxbMarshaller = jaxbContext.createMarshaller();
jaxbMarshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
//write to System.out
jaxbMarshaller.marshal(employeeMap, System.out);
//write to File JAXBMarshalOutput.xml
jaxbMarshaller.marshal(employeeMap, new File("JAXBMarshalOutput.xml"));
} catch (JAXBException ex) {
ex.printStackTrace();
}
}
}

Step 5: Build and Run ứng dụng

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Bài 4.5
Sử dụng JAXB lấy dữ liệu từ file xml đẩy vào java object và in ra màn hình
 Employees.xml

 Output:
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Step 1: Tạo object Employee để lấy dữ liệu của element employee trong file xml
 Employee.java
package jaxb;
import javax.xml.bind.annotation.XmlAttribute;
import javax.xml.bind.annotation.XmlElement;
/**
*

* @author DELL
*/
public class Employee {
private int id;
private String firstName;
private String lastName;
private String location;
public Employee(){}
public Employee(int id, String firstName, String lastName,String location){
super();
this.id = id;
this.firstName = firstName;
this.lastName = lastName;
this.location = location;
}
//getter and setter Attribute id
@XmlAttribute
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
//getter and setter element firstname
@XmlElement
public String getFirstName() {
return firstName;
}
public void setFirstName(String firstName) {
this.firstName = firstName;

}
//getter and setter element lastname
@XmlElement
public String getLastName() {

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return lastName;
}
public void setLastName(String lastName) {
this.lastName = lastName;
}
//getter and setter element location
@XmlElement
public String getLocation() {
return location;
}
public void setLocation(String location) {
this.location = location;
}
}

Step 2: Tạo List chứa các object employee
 Employees.java

package jaxb;
import java.util.List;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;
/**
*
* @author DELL
*/
@XmlRootElement(name = "employees")
public class Employees {
private List<Employee> employees;
public Employees(){}
public Employees(List<Employee> employees){
super();
this.employees=employees;
}
@XmlElement(name = "employee")
public List<Employee> getEmployees() {
return employees;
}
public void setEmployees(List<Employee> employees) {
this.employees = employees;
}
}

Step 3: Triển khai hàm main ứng dụng để lấy dữ liệu từ file xml vào java object
package jaxb;
import java.io.File;
import java.util.List;
import javax.xml.bind.JAXBContext;

import javax.xml.bind.JAXBException;

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Processing XML Using Java
import javax.xml.bind.Unmarshaller;
/**
*
* @author DELL
*/
public class JAXB {
/**
* @param args the command line arguments
*/
public static void main(String[] args) {
//Create File form Employees.xml
File file = new File("Employees.xml");
try {
//Create JAXB Context
JAXBContext jaxbContext = JAXBContext.newInstance(Employees.class);
//Create Unmarshaller
Unmarshaller jaxbUnmarshaller = jaxbContext.createUnmarshaller();
//Get List<employee> Employees form Unmarshaller and file
Employees emp = (Employees) jaxbUnmarshaller.unmarshal(file);
System.out.println("employees:");

List<Employee> listemp = emp.getEmployees();
//Print each employee in list<employee> Employees
for (Employee empl : listemp) {
System.out.println(empl.getId() + " " + empl.getFirstName() + " " + empl.getLastName() + " " +
empl.getLocation());
}
} catch (JAXBException ex) {
ex.printStackTrace();
}
}
}

Step 4: Build and Run ứng dụng

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