No plugin found for prefix - Maven - jpa-2.0

Question

I have used maven to generate metamodel for JPA entities
But I'm getting the following error:
[ERROR] No plugin found for prefix 'maven-compiler-plugin' in the current project
and in the plugin groups [org.apache.maven.plugins, org.codehaus.mojo] available
from the repositories [local, central (http://repo.maven.apache.org/maven2)] -> [Help 1]
org.apache.maven.plugin.prefix.NoPluginFoundForPrefixException: No plugin found
for prefix 'maven-compiler-plugin' in the current project and in the plugin groups
[org.apache.maven.plugins, org.codehaus.mojo] available from the repositories
[local, central (http://repo.maven.apache.org/maven2)]
at org.apache.maven.plugin.prefix.internal.DefaultPluginPrefixResolver.resolve(DefaultPluginPrefixResolver.java:93)
at org.apache.maven.lifecycle.internal.MojoDescriptorCreator.findPluginForPrefix(MojoDescriptorCreator.java:260)
at org.apache.maven.lifecycle.internal.MojoDescriptorCreator.getMojoDescriptor(MojoDescriptorCreator.java:220)
at org.apache.maven.lifecycle.internal.DefaultLifecycleTaskSegmentCalculator.calculateTaskSegments(DefaultLifecycleTaskSegmentCalculator.java:106)
at org.apache.maven.lifecycle.internal.DefaultLifecycleTaskSegmentCalculator.calculateTaskSegments(DefaultLifecycleTaskSegmentCalculator.java:86)
at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:98)
at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:317)
at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:152)
at org.apache.maven.cli.MavenCli.execute(MavenCli.java:555)
at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:214)
at org.apache.maven.cli.MavenCli.main(MavenCli.java:158)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:289)
at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229)
at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415)
at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356)
And my pom.xml is
<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/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<packaging>war</packaging>
<version>1.0-SNAPSHOT</version>
<groupId>com.signalmapper</groupId>
<artifactId>SignalMapper</artifactId>
<properties>
<appengine.target.version>1.9.15</appengine.target.version>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<spring.version>4.0.1.RELEASE</spring.version>
<build.directory>./war/WEB-INF</build.directory>
<datanucleus.version>3.1.3</datanucleus.version>
</properties>
<dependencies>
<!-- Compile/runtime dependencies -->
<!-- Spring dependencies -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-test</artifactId>
<version>${spring.version}</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>${spring.version}</version>
<exclusions>
<!-- Exclude Commons Logging in favor of SLF4j -->
<exclusion>
<groupId>commons-logging</groupId>
<artifactId>commons-logging</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aspects</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-orm</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>${spring.version}</version>
</dependency>
<!-- App Engine dependencies -->
<dependency>
<groupId>com.google.appengine</groupId>
<artifactId>appengine-api-1.0-sdk</artifactId>
<version>${appengine.target.version}</version>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>servlet-api</artifactId>
<version>2.5</version>
<scope>provided</scope>
</dependency>
<!-- Datanucleus persistence -->
<dependency>
<groupId>com.google.appengine.orm</groupId>
<artifactId>datanucleus-appengine</artifactId>
<version>2.0.1.1</version>
</dependency>
<dependency>
<groupId>org.datanucleus</groupId>
<artifactId>datanucleus-core</artifactId>
<version>${datanucleus.version}</version>
</dependency>
<dependency>
<groupId>org.datanucleus</groupId>
<artifactId>datanucleus-api-jpa</artifactId>
<version>${datanucleus.version}</version>
</dependency>
<dependency>
<groupId>org.apache.geronimo.specs</groupId>
<artifactId>geronimo-jpa_2.0_spec</artifactId>
<version>1.0</version>
</dependency>
<dependency>
<groupId>org.datanucleus</groupId>
<artifactId>datanucleus-enhancer</artifactId>
<version>3.1.1</version>
</dependency>
<dependency>
<groupId>javax.persistence</groupId>
<artifactId>persistence-api</artifactId>
<version>1.0.2</version>
<scope>provided</scope>
</dependency>
<!-- JSON-parser dependencies -->
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-core</artifactId>
<version>2.2.3</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.2.3</version>
</dependency>
<dependency>
<groupId>org.codehaus.jackson</groupId>
<artifactId>jackson-core-asl</artifactId>
<version>1.9.13</version>
</dependency>
<!-- Spring data JPA dependency -->
<dependency>
<groupId>org.springframework.data</groupId>
<artifactId>spring-data-jpa</artifactId>
<version>1.7.1.RELEASE</version>
</dependency>
<!-- slf4j dependency -->
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-simple</artifactId>
<version>1.7.7</version>
</dependency>
<dependency>
<groupId>javax</groupId>
<artifactId>javaee-api</artifactId>
<version>6.0</version>
<scope>provided</scope>
</dependency>
</dependencies>
<build>
<outputDirectory>${build.directory}/classes</outputDirectory>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<version>2.5.1</version>
<artifactId>eccompiler-plugin</artifactId>
<configuration>
<source>1.7</source>
<target>1.7</target>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-war-plugin</artifactId>
<executions>
<execution>
<id>default-war</id>
<phase>prepare-package</phase>
<configuration>
<failOnMissingWebXml>false</failOnMissingWebXml>
<archiveClasses>false</archiveClasses>
<archive>
<manifest>
<addClasspath>true</addClasspath>
<classpathPrefix />
</manifest>
</archive>
</configuration>
</execution>
</executions>
<version>2.3</version>
<configuration>
<archiveClasses>true</archiveClasses>
</configuration>
</plugin>
<plugin>
<groupId>com.google.appengine</groupId>
<artifactId>appengine-maven-plugin</artifactId>
<version>${appengine.target.version}</version>
</plugin>
<plugin>
<artifactId>maven-dependency-plugin</artifactId>
<executions>
<execution>
<phase>process-sources</phase>
<goals>
<goal>copy-dependencies</goal>
</goals>
<configuration>
<outputDirectory>${build.directory}/lib</outputDirectory>
</configuration>
</execution>
</executions>
</plugin>
<plugin>
<groupId>org.datanucleus</groupId>
<artifactId>maven-datanucleus-plugin</artifactId>
<version>3.0.2</version>
<configuration>
<api>JPA</api>
<metadataDirectory>${build.directory}/classes/com/signalmapper/data/model</metadataDirectory>
<metadataIncludes>**/*.class</metadataIncludes>
<persistenceUnitName>transactions-optional</persistenceUnitName>
<verbose>true</verbose>
<resources>
<resource>
<filtering>true</filtering>
<directory>src/resources/META-INF</directory>
<includes>
<include>persistence.xml</include>
</includes>
</resource>
</resources>
</configuration>
<dependencies>
<dependency>
<groupId>org.datanucleus</groupId>
<artifactId>datanucleus-core</artifactId>
<version>${datanucleus.version}</version>
</dependency>
</dependencies>
<executions>
<execution>
<phase>process-classes</phase>
<goals>
<goal>enhance</goal>
</goals>
</execution>
</executions>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<executions>
<execution>
<id>generate-entity-metamodel</id>
<phase>generate-sources</phase>
<goals>
<goal>compile</goal>
</goals>
<configuration>
<source>1.6</source>
<target>1.6</target>
<optimize>true</optimize>
<showDeprecation>true</showDeprecation>
<showWarnings>true</showWarnings>
<proc>only</proc>
<compilerArgument>-Aopenjpa.metamodel=true</compilerArgument>
<generatedSourcesDirectory>${build.directory}/generated-sources</generatedSourcesDirectory>
<compilerArguments>
<processor>org.apache.openjpa.persistence.meta.AnnotationProcessor6</processor>
</compilerArguments>
</configuration>
</execution>
<execution>
<id>compile</id>
<phase>compile</phase>
<goals>
<goal>compile</goal>
</goals>
<configuration>
<source>1.6</source>
<target>1.6</target>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>
I am newbie to maven and I don't know what am I missing?
Any help would be highly appreciated.