Get Data From the XML File
Here you will learn to
retrieve data from XML file using SAX parser. We use the JAXP
APIs to retrieve data from XML document .
Description of program:
In this example you need a well-formed XML file that
has some data (Emp_Id, Emp_Name and Emp_E-mail in our case). Create a
java program (EmployeeDetails.java) that retrieves data from it. When you
run the program it asks for a file with a message "Enter XML file
name:" at the command line and checks its existence through exists()
method. If the given file exits, the instance of SAXParser class parses
the file using the parse()
method.
Till the startElement() method returns 'true', the characters()
method prints data . If the file doesn't exist it will display a message
"File not found!".
Characters(char[] ch, int start, int len)
method retrieves identification of character data. The Parser calls this method
and to report every character data encountered . If any error occurs it throws
the SAXException. This method takes the following parameters:
ch:
This is the characters of XML document.
start: This is staring position
in an array.
len: This is the number of
characters to read from an array.
Here is the XML File: Employee-Detail.xml
<?xml version = "1.0" ?>
<Employee-Detail>
<Employee>
<Emp_Id> E-001 </Emp_Id>
<Emp_Name> Vinod </Emp_Name>
<Emp_E-mail> Vinod1@yahoo.com </Emp_E-mail>
</Employee>
<Employee>
<Emp_Id> E-002 </Emp_Id>
<Emp_Name> Amit </Emp_Name>
<Emp_E-mail> Amit2@yahoo.com </Emp_E-mail>
</Employee>
<Employee>
<Emp_Id> E-003 </Emp_Id>
<Emp_Name> Deepak </Emp_Name>
<Emp_E-mail> Deepak3@yahoo.com </Emp_E-mail>
</Employee>
</Employee-Detail> |
Here is the Java File: EmployeeDetails.java
import javax.xml.parsers.*;
import org.xml.sax.*;
import org.xml.sax.helpers.*;
import java.io.*;
public class EmployeeDetails{
public static void main(String[] args) throws IOException{
BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
System.out.print("Enter XML file name:");
String xmlFile = bf.readLine();
EmployeeDetails detail = new EmployeeDetails(xmlFile);
}
public EmployeeDetails(String str){
try{
File file = new File(str);
if (file.exists()){
SAXParserFactory parserFact = SAXParserFactory.newInstance();
SAXParser parser = parserFact.newSAXParser();
System.out.println("XML Data: ");
DefaultHandler dHandler = new DefaultHandler(){
boolean id;
boolean name;
boolean mail;
public void startElement(String uri, String localName,
String element_name, Attributes attributes)throws SAXException{
if (element_name.equals("Emp_Id")){
id = true;
}
if (element_name.equals("Emp_Name")){
name = true;
}
if (element_name.equals("Emp_E-mail")){
mail = true;
}
}
public void characters(char[] ch, int start, int len) throws SAXException{
String str = new String (ch, start, len);
if (id){
System.out.println("Emp_Id: "+str);
id = false;
}
if (name){
System.out.println("Name: "+str);
name = false;
}
if (mail){
System.out.println("E-mail: "+str);
mail = false;
}
}
};
parser.parse(str, dHandler);
}
else{
System.out.println("File not found!");
}
}
catch (Exception e){
System.out.println("XML File hasn't any elements");
e.printStackTrace();
}
}
}
|
Download this example
Output of program:
C:\vinod\xml\comXML>javac EmployeeDetails.java
C:\vinod\xml\comXML>java EmployeeDetails
Enter XML file name:Employee-Detail.xml
XML Data:
Emp_Id: E-001
Name: Vinod
E-mail: Vinod1@yahoo.com
Emp_Id: E-002
Name: Amit
E-mail: Amit2@yahoo.com
Emp_Id: E-003
Name: Deepak
E-mail: Deepak3@yahoo.com |
|
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