parent tag in Maven

[Kousik Majumder]

Hi all,

I am new to Maven.
Can somebody tell me what is the use of "parent" tag in maven? Does it involves more than one pom.xml file or not etc.?
I can not find any good documentaion to understand it.

[David Newton]

http://maven.apache.org/pom.html#Inheritance

[udaykiran pulipati]

If you have 3 maven projects and 1 web project, With out re declaring dependency in child project just refer below Element in child pom.xml file

<parent>
    <artifactId>MySqlMaven</artifactId>
    <groupId>MySqlMaven</groupId>
    <version>0.0.1-SNAPSHOT</version>
  </parent>

For Example MySqlMavenServices is a Maven project it is referred to MySqlMavenWeb project
pom.xml file in MySqlMavenServices

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <parent>
    <artifactId>MySqlMaven</artifactId>
    <groupId>MySqlMaven</groupId>
    <version>0.0.1-SNAPSHOT</version>
  </parent>
  <groupId>com.test.mysqlmavenservices</groupId>
  <artifactId>MySqlMavenServices</artifactId>
  <name>MySqlMavenServices</name>
  <description>MySqlMavenServices</description>
  <build>
    <plugins>
      <plugin>
        <artifactId>maven-compiler-plugin</artifactId>
        <configuration>
          <source>1.6</source>
          <target>1.6</target>
        </configuration>
      </plugin>
    </plugins>
  </build>
</project>

pom.xml file in MySqlMavenWeb project

<?xml version="1.0"?>
<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <modelVersion>4.0.0</modelVersion>
  <groupId>MySqlMaven</groupId>
  <artifactId>MySqlMaven</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>pom</packaging>
  <name></name>
  <description></description>
  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <spring.version>3.2.6.RELEASE</spring.version>
	<hibernate.version>4.3.0.Final</hibernate.version>
  </properties>
  <dependencies>
    <dependency>
      <groupId>javax.servlet</groupId>
      <artifactId>jstl</artifactId>
      <version>1.2</version>
      <scope>provided</scope>
    </dependency>
    <dependency>
      <groupId>javax.servlet.jsp</groupId>
      <artifactId>jsp-api</artifactId>
      <version>2.1</version>
      <scope>provided</scope>
    </dependency>
    <dependency>
      <groupId>org.glassfish</groupId>
      <artifactId>javax.annotation</artifactId>
      <version>3.0.1</version>
    </dependency>
    <dependency>
      <groupId>org.glassfish</groupId>
      <artifactId>javax.ejb</artifactId>
      <version>3.0.1</version>
    </dependency>
    <dependency>
      <groupId>org.jboss.weld</groupId>
      <artifactId>weld-osgi-bundle</artifactId>
      <version>1.0.1-SP3</version>
    </dependency>
    <dependency>
      <groupId>org.glassfish</groupId>
      <artifactId>javax.servlet</artifactId>
      <version>3.0.1</version>
    </dependency>
    
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>5.1.28</version>
    </dependency>
    <dependency>
		<groupId>javax.mail</groupId>
		<artifactId>mail</artifactId>
		<version>1.4.7</version>
	</dependency>
	<dependency>
		<groupId>org.springframework</groupId>
		<artifactId>spring-orm</artifactId>
		<version>${spring.version}</version>
	</dependency>
	<dependency>
		<groupId>org.springframework</groupId>
		<artifactId>spring-web</artifactId>
		<version>${spring.version}</version>
	</dependency>
	<dependency>
		<groupId>org.springframework</groupId>
		<artifactId>spring-webmvc</artifactId>
		<version>${spring.version}</version>
	</dependency>
	<dependency>
		<groupId>commons-dbcp</groupId>
		<artifactId>commons-dbcp</artifactId>
		<version>1.4</version>
	</dependency>
	<dependency>
		<groupId>org.hibernate</groupId>
		<artifactId>hibernate-core</artifactId>
		<version>${hibernate.version}</version>
	</dependency>
	
	<dependency>
		<groupId>org.hibernate</groupId>
		<artifactId>hibernate-entitymanager</artifactId>
		<version>${hibernate.version}</version>
	</dependency>
	
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-aop</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-aspects</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-beans</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-context</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-context-support</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-core</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-expression</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-instrument</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-instrument-tomcat</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>aopalliance</groupId>
      <artifactId>aopalliance</artifactId>
      <version>1.0</version>
    </dependency>
    <dependency>
      <groupId>org.aspectj</groupId>
      <artifactId>aspectjweaver</artifactId>
      <version>1.6.9</version>
    </dependency>
    <dependency>
      <groupId>cglib</groupId>
      <artifactId>cglib-nodep</artifactId>
      <version>2.2</version>
    </dependency>
    <dependency>
      <groupId>commons-pool</groupId>
      <artifactId>commons-pool</artifactId>
      <version>1.5.3</version>
    </dependency>
    <dependency>
      <groupId>commons-collections</groupId>
      <artifactId>commons-collections</artifactId>
      <version>3.2</version>
    </dependency>
    <dependency>
      <groupId>commons-logging</groupId>
      <artifactId>commons-logging</artifactId>
      <version>1.1.1</version>
    </dependency>
    <dependency>
      <groupId>log4j</groupId>
      <artifactId>log4j</artifactId>
      <version>1.2.16</version>
    </dependency>
  </dependencies>
  <build>
    <plugins>
      <plugin>
        <artifactId>maven-war-plugin</artifactId>
      </plugin>
      <plugin>
        <artifactId>maven-compiler-plugin</artifactId>
        <configuration>
          <source>1.6</source>
          <target>1.6</target>
        </configuration>
      </plugin>
    </plugins>
  </build>
</project>