Using SAX parsing to read XML files

XML This is my first blog, today in the "Java Application Development detailed" a book, the book is about XML programming, so according to the steps of the book to test themselves, but how to test is not successful, and then I looked over the source, found in the reading of the location of the XML file is wrong, and then made changes, Also great, the heart gush out a sense of achievement, is to post the source code and give a bit to share:

Using an XML file to connect to the MySQL database, the Database.conf.xml file is as follows:

<database-conf>
<datasource>
<driver>com.mysql.jdbc.Driver</driver>
<url>jdbc:mysql://127.0.0.1:3306/j2ee14</url>
<user>bn</user>
<password>bn</password>
</datasource>
</database-conf>

Create a new handler to resolve the XML configuration (Configparser.java):

Package COM.J2EE14.CH4;
Import org.xml.sax.Attributes;
Import Org.xml.sax.helpers.DefaultHandler;
Import org.xml.sax.SAXException;

Import java.util.Properties;

/**
*configparser extends DefaultHandler, which is used to obtain connection properties for the database
*/
public class Configparser extends DefaultHandler
{
Define a property to hold the attribute value
Private Properties props;
Private String Currentname;
Private StringBuffer CurrentValue =new stringbuffer ();

Builder Initialization Props

Public Configparser ()
{
This.props=new Properties ();
}
Public Properties GetProps ()
{
return this.props;
}

Defines a method that begins parsing an element. This is to extract the name xxx from <xxx>

public void Startelement (String uri,string localname,string qname,attributes Attributes) throws Saxexception
{
Currentvalue.delete (0,currentvalue.length ());
This.currentname=qname;
}

This is to add the value between <xxx></xxx> to CurrentValue

public void characters (char[] ch, int start, int length) throws Saxexception {

Currentvalue.append (CH, start, length);

}

/**
* Save the related attributes in the XML configuration file to the Properties object
*/

public void EndElement (String uri,string localname,string qName) throws Saxexception
{
Props.put (Qname.tolowercase (), currentvalue.tostring (). Trim ());
}
}

A class used to parse XML, which other programs use to obtain the connection properties of the database (Parsedatabaseconfig
. Java):

Package COM.J2EE14.CH4;

Import java.util.Properties;
Import Javax.xml.parsers.SAXParser;
Import Javax.xml.parsers.SAXParserFactory;

/**
* Other programs through the Parsedatabaseconfig to obtain the configuration information of the database,
* This makes the coupling between classes loosely
*/
public class Parsedatabaseconfig
{
Define a property to hold the attribute value
Private Properties props;

Public Properties GetProps ()
{
return this.props;
}
/**
* Parse XML configuration file, save attributes
*/
public void Parse (String filename) throws Exception
{
The object of our parser
Configparser handler=new Configparser ();

Get Sax Factory Objects
SAXParserFactory factory=saxparserfactory.newinstance ();
Factory.setnamespaceaware (FALSE);
Factory.setvalidating (FALSE);

Get Sax parsing
SAXParser Parser=factory.newsaxparser ();

Try
{
To associate the parser with parsing object XML, start parsing
Parser.parse (Filename,handler);

Gets the properties after the resolution is successful
Props=handler.getprops ();
}
Finally
{
Factory=null;
Parser=null;
Handler=null;
}
}

}

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