ArtifactDescriptorException: Failed to read artifact descriptor for javax.servlet:servlet-api:jar:${as.default.javax.servlet.version} - maven

Question

I am using maven with my multi module project. I am not able to solve the error.
The error is given below :
Description Resource Path Location Type
ArtifactDescriptorException: Failed to read artifact descriptor for javax.servlet:servlet-api:jar:${as.default.javax.servlet.version}: ArtifactResolutionException: Failure to transfer javax.servlet:servlet-api:pom:${as.default.javax.servlet.version} from http://repo.maven.apache.org/maven2 was cached in the local repository, resolution will not be reattempted until the update interval of central has elapsed or updates are forced. Original error: Could not transfer artifact javax.servlet:servlet-api:pom:${as.default.javax.servlet.version} from/to central (http://repo.maven.apache.org/maven2): Illegal character in path at index 63: http://repo.maven.apache.org/maven2/javax/servlet/servlet-api/${as.default.javax.servlet.version}/servlet-api-${as.default.javax.servlet.version}.pom pom.xml /kern-web-proxy line 1 Maven Dependency Problem
I am just a beginner in maven so any help is valuable for me.
here is pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<artifactId>kern</artifactId>
<groupId>com.appamsoft.as</groupId>
<version>0.1-SNAPSHOT</version>
</parent>
<groupId>com.appamsoft.as.kern</groupId>
<artifactId>kern-web-proxy</artifactId>
<!-- <version>0.1-SNAPSHOT</version> -->
<packaging>war</packaging>
<name>kern-web-proxy</name>
<dependencies>
<dependency>
<groupId>com.appamsoft.as.kern</groupId>
<artifactId>kern-core</artifactId>
<version>0.1-SNAPSHOT</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>${as.default.springframework.version}</version>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>servlet-api</artifactId>
<version>${as.default.javax.servlet.version}</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>javax.servlet.jsp</groupId>
<artifactId>jsp-api</artifactId>
<version>${as.default.javax.servlet.jsp.version}</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>${as.default.slf4j.version}</version>
</dependency>
<!-- <dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
</dependency>
-->
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>${as.default.log4j.version}</version>
</dependency>
<dependency>
<groupId>com.thoughtworks.xstream</groupId>
<artifactId>xstream</artifactId>
<version>1.4.2</version>
</dependency>
<dependency>
<groupId>javax</groupId>
<artifactId>javaee-web-api</artifactId>
<version>7.0</version>
<scope>provided</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>2.0.2</version>
<configuration>
<source>${as.default.java.version}</source>
<target>${as.default.java.version}</target>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-eclipse-plugin</artifactId>
<version>2.5</version>
<configuration>
<wtpversion>2.0</wtpversion>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-war-plugin</artifactId>
<version>2.3</version>
<configuration>
<failOnMissingWebXml>false</failOnMissingWebXml>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-dependency-plugin</artifactId>
<version>2.6</version>
<executions>
<execution>
<phase>validate</phase>
<goals>
<goal>copy</goal>
</goals>
<configuration>
<outputDirectory>${endorsed.dir}</outputDirectory>
<silent>true</silent>
<artifactItems>
<artifactItem>
<groupId>javax</groupId>
<artifactId>javaee-endorsed-api</artifactId>
<version>7.0</version>
<type>jar</type>
</artifactItem>
</artifactItems>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>
<properties>
<endorsed.dir>${project.build.directory}/endorsed</endorsed.dir>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>
</project>
The screenshot of the multi module maven project is as follows:
And the top most pom of as project is given below:
<?xml version="1.0" encoding="UTF-8"?>
<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>
<groupId>com.appamsoft</groupId>
<artifactId>as</artifactId>
<version>0.1-SNAPSHOT</version>
<packaging>pom</packaging>
<name>as</name>
<modules>
<module>tools</module>
<module>kern</module>
</modules>
<properties>
<as.default.java.version>1.7</as.default.java.version>
<as.default.junit.version>4.8.2</as.default.junit.version>
<as.default.slf4j.version>1.6.6</as.default.slf4j.version>
<as.default.log4j.version>1.2.16</as.default.log4j.version>
<as.default.javax.servlet.version>2.5</as.default.javax.servlet.version>
<as.default.javax.servlet.jsp.version>2.1</as.default.javax.servlet.jsp.version>
<as.default.springframework.version>4.0.3.RELEASE</as.default.springframework.version>
<as.default.hibernate.version>3.5.0-Final</as.default.hibernate.version>
<as.default.camel.version>2.9.4</as.default.camel.version>
<as.default.activemq.version>5.6.0</as.default.activemq.version>
<project.build.maven.compiler.plugin.version>2.3.2</project.build.maven.compiler.plugin.version>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>${as.default.slf4j.version}</version>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
<version>${as.default.slf4j.version}</version>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>${as.default.log4j.version}</version>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>${as.default.junit.version}</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>servlet-api</artifactId>
<version>${as.default.javax.servlet.version}</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>javax.servlet.jsp</groupId>
<artifactId>jsp-api</artifactId>
<version>${as.default.javax.servlet.jsp.version}</version>
<scope>provided</scope>
</dependency>
</dependencies>
</dependencyManagement>
<build>
<pluginManagement>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>1.5</source>
<target>1.5</target>
</configuration>
</plugin>
</plugins>
</pluginManagement>
</build>
</project>

Answer 1

Your parent section of the kern-web-proxy should be:
<parent>
<groupId>com.appamsoft</groupId>
<artifactId>as</artifactId>
<version>0.1-SNAPSHOT</version>
</parent>
or else it cannot resolve the properties. However, your parent's coordinates are resolving to something, most likely an older version, or else you would be getting another error (something along the lines of "non-resolvable parent").
The assumes that the parent POM is available one directory above kern-web-proxy. If that is not the case, you need to add adjust your parent section with a <relativePath> tag:
<parent>
<groupId>com.appamsoft</groupId>
<artifactId>as</artifactId>
<version>0.1-SNAPSHOT</version>
<!-- This should point to your parent POM if is not located at '..' -->
<relativePath>../..</relativePath>
</parent>

Answer 2

First i looked in local repo (.m2) there is name mismatch of jar's which were being used by me in kern-web-proxy pom.xml. So, I matched the jar's name as well as version number to local repo jar's. Then i got the solution of this error.