Error displayed in the eclipse at pom.xml is given below:

Multiple annotations found at this line:
- CoreException: Could not calculate build plan: Plugin org.apache.maven.plugins:maven-compiler-plugin:2.5.1 or one of
its dependencies could not be resolved: Failed to read artifact descriptor for org.apache.maven.plugins:maven-compiler-plugin:jar:
2.5.1: ArtifactResolutionException: Failure to transfer org.apache.maven.plugins:maven-compiler-plugin:pom:2.5.1 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 org.apache.maven.plugins:maven-compiler-
plugin:pom:2.5.1 from/to central (http://repo.maven.apache.org/maven2): Failed to transfer http://repo.maven.apache.org/maven2/
org/apache/maven/plugins/maven-compiler-plugin/2.5.1/maven-compiler-plugin-2.5.1.pom. Error code 501, HTTPS Required
- Plugin execution not covered by lifecycle configuration: org.apache.maven.plugins:maven-compiler-plugin:
2.5.1:testCompile (execution: default-testCompile, phase: test-compile)
- CoreException: Could not calculate build plan: Plugin org.apache.maven.plugins:maven-compiler-plugin:2.5.1 or one of
its dependencies could not be resolved: Failed to read artifact descriptor for org.apache.maven.plugins:maven-compiler-plugin:jar:
2.5.1: ArtifactResolutionException: Could not transfer artifact org.apache.maven.plugins:maven-compiler-plugin:pom:2.5.1 from/to
central (http://repo.maven.apache.org/maven2): Failed to transfer http://repo.maven.apache.org/maven2/org/apache/maven/
plugins/maven-compiler-plugin/2.5.1/maven-compiler-plugin-2.5.1.pom. Error code 501, HTTPS Required
- Plugin execution not covered by lifecycle configuration: org.apache.maven.plugins:maven-compiler-plugin:2.5.1:compile
(execution: default-compile, phase: compile)