How to read XML Property value using Java

I need to read X开发者_运维问答ML data by using java.

This is my XML file snippet.

<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
    <session-factory>

        <!-- Database connection settings -->
    <property name="hibernate.connection.provider_class">org.hibernate.connection.C3P0ConnectionProvider</property> 
        <property name="connection.driver_class">com.mysql.jdbc.Driver</property>

        <property name="connection.url">jdbc:mysql://192.168.1.55/tisas</property>
        <property name="connection.username">root</property>
        <property name="connection.password">xxyy</property>
        <property name="show_sql">false</property> 

I need to get the value(jdbc:mysql://192.168.1.55/tisas) from the xml file using java. how can i get it?

Assuming Hibernate libraries are available, and the properties file is stored in config.xml:

new Configuration().addFile("config.xml").getProperty("connection.url")

There is a multitude of ways to achieve this. I assume you read this once for a long-running application, so performance shouldn't be an issue. Therefore, I'd go for the Java XPath API (Tutorial).

Here is a fully working example using XPath (note: just replace the StringReader with any Reader that's appropriate for your usecae - e.g. a FileReader):

import java.io.StringReader;
import javax.xml.xpath.XPathFactory;
import org.xml.sax.InputSource;

public class XPath {
  public static void main(String[] args) throws Exception {
    String xml = "<hibernate-configuration><session-factory><property name=\"hibernate.connection.provider_class\">org.hibernate.connection.C3P0ConnectionProvider</property><property name=\"connection.driver_class\">com.mysql.jdbc.Driver</property><property name=\"connection.url\">jdbc:mysql://192.168.1.55/tisas</property></session-factory></hibernate-configuration>";
    String connectionUrl = XPathFactory.newInstance().newXPath().compile("//session-factory/property[@name='connection.url']/text()").evaluate(new InputSource(new StringReader(xml)));
    System.out.println("connectionUrl = " + connectionUrl);
  }
}

I wouldn't go for a DOM (as suggested by Ram) if you only need a single value from the file, it will require more code.

Use dom4j and its documentation has very many examples on how to achieve what you intend to do

Here's an example using the Xerces library:

String xpath = "/hibernate-configuration/session-factory/property[@name='connection.url']/text()";

// Create the builder and parse the file
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
factory.setValidating(false);


Document doc = factory.newDocumentBuilder().parse(new File("src/xml/input.xml"));

// Get the matching elements
String url = org.apache.xpath.XPathAPI.selectNodeList(doc, xpath).item(0).getNodeValue();
System.out.println(url);