Thực hành sử dụng XML trong Java Lab 4

IT Research Department @BKAP 2015 Trang 1 / 19 Lab 04 StAX and JAXB Mục tiêu - Sử dụng XMLStreamReader đọc nội dung XML - Sử dụng XMLStreamWriter ghi file XML - Sử dụng XMLEventReader

IT Research Department @BKAP 2015 Trang 1 / 19

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

 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 license header, choose License Headers in Project Properties

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>

<CreditCardLimit="10,000"Currency="USD">

<Number>9921 5681 2521 8845</Number>

IT Research Department @BKAP 2015 Trang 3 / 19

<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

*/

publicclass BKXMLStreamReader {

publicstaticvoid 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());

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

*/

publicclass StAX {

/**

* @param args the command line arguments

*/

publicstaticvoid main(String[] args) {

try {

//Reader

File file = new File("ccinfo.xml");

BKXMLStreamReader bSR = new BKXMLStreamReader();

bSR.StreamReader(file);

} catch (Exception e) {

e.printStackTrace();

}

}

}

IT Research Department @BKAP 2015 Trang 5 / 19

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

package stax;

import java.io.File;

import java.io.FileWriter;

import javax.xml.stream.XMLOutputFactory;

import javax.xml.stream.XMLStreamWriter;

/**

*

* @author DELL

*/

publicclass BKXMLStreamWriter {

publicstaticvoid 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

*/

publicclass StAX {

/**

* @param args the command line arguments

*/

IT Research Department @BKAP 2015 Trang 7 / 19

publicstaticvoid 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

 Output

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

package stax;

import java.io.Reader;

import java.util.Iterator;

import javax.xml.namespace.QName;

IT Research Department @BKAP 2015 Trang 9 / 19

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

*/

publicclass BKXMLEventReader {

publicstaticvoid 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();

}

}

}

 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

*/

publicclass StAX {

/**

* @param args the command line arguments

*/

publicstaticvoid 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

IT Research Department @BKAP 2015 Trang 11 / 19

Bài 4.4

Sử dụng JAXB để chuyển java object thành file xml

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)

publicclass JAXBEmployee {

private Integer id;

private String firstName;

private String lastName;

privatedouble income;

public Integer getId() {

return id;

}

publicvoid setId(Integer id) {

this.id = id;

}

public String getFirstName() {

return firstName;

}

publicvoid setFirstName(String firstName) {

this.firstName = firstName;

}

public String getLastName() {

return lastName;

}

publicvoid setLastName(String lastName) {

this.lastName = lastName;

}

publicdouble getIncome() {

return income;

}

IT Research Department @BKAP 2015 Trang 13 / 19

publicvoid 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)

publicclass EmployeeMap

{

private Map<Integer,JAXBEmployee> employeeMap = new HashMap<Integer, JAXBEmployee>();

public Map<Integer, JAXBEmployee> getEmployeeMap() {

return employeeMap;

}

publicvoid 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

*/

publicclass JAXB {

/**

* @param args the command line arguments

*/

publicstaticvoid 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

IT Research Department @BKAP 2015 Trang 15 / 19

Bài 4.5

Sử dụng JAXB lấy dữ liệu từ file xml đẩy vào java object và in ra màn hình

 Employees.xml

 Output:

IT Research Department @BKAP 2015 Trang 17 / 19

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

*/

publicclass Employee {

privateint 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

publicint getId() {

return id;

}

publicvoid setId(int id) {

this.id = id;

}

//getter and setter element firstname

@XmlElement

public String getFirstName() {

return firstName;

}

publicvoid setFirstName(String firstName) {

this.firstName = firstName;

}

//getter and setter element lastname

@XmlElement

public String getLastName() {