eclipse - m2eclipse error

Question

I am developing a web application with Eclipse and I generate the project with a maven archetype.

When I enable maven dependency management, Eclipse mark some errors in the pom file, this error is:

 Multiple annotations found at this line:
- Execution default-testResources of goal org.apache.maven.plugins:maven-resources-          plugin:2.4.3:testResources failed: 
 Plugin org.apache.maven.plugins:maven-resources-plugin:2.4.3 or one of its dependencies could not be resolved: Failed to collect 
 dependencies for org.apache.maven.plugins:maven-resources-plugin:jar:2.4.3 () (org.apache.maven.plugins:maven-resources-
 plugin:2.4.3:testResources:default-testResources:process-test-resources)
- Plugin execution not covered by lifecycle configuration: org.apache.maven.plugins:maven-compiler-plugin:2.3.2:compile 
 (execution: default-compile, phase: compile)
- CoreException: Could not get the value for parameter compilerId for plugin execution default-compile: 
 PluginResolutionException: Plugin org.apache.maven.plugins:maven-compiler-plugin:2.3.2 or one of its dependencies could not be 
 resolved: Failed to collect dependencies for org.apache.maven.plugins:maven-compiler-plugin:jar:2.3.2 (): 
 ArtifactDescriptorException: Failed to read artifact descriptor for org.apache.maven:maven-plugin-api:jar:2.0.6: 
 ArtifactResolutionException: Failure to transfer org.apache.maven:maven-plugin-api:pom:2.0.6 from http://repo1.maven.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:maven-plugin-api:pom:2.0.6 from/to central (http://
 repo1.maven.org/maven2): null to http://repo1.maven.org/maven2/org/apache/maven/maven-plugin-api/2.0.6/maven-plugin-
 api-2.0.6.pom
- CoreException: Could not get the value for parameter compilerId for plugin execution default-testCompile: 
 PluginResolutionException: Plugin org.apache.maven.plugins:maven-compiler-plugin:2.3.2 or one of its dependencies could not be 
 resolved: Failed to collect dependencies for org.apache.maven.plugins:maven-compiler-plugin:jar:2.3.2 (): 
 ArtifactDescriptorException: Failed to read artifact descriptor for org.apache.maven:maven-plugin-api:jar:2.0.6: 
 ArtifactResolutionException: Failure to transfer org.apache.maven:maven-plugin-api:pom:2.0.6 from http://repo1.maven.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:maven-plugin-api:pom:2.0.6 from/to central (http://
 repo1.maven.org/maven2): null to http://repo1.maven.org/maven2/org/apache/maven/maven-plugin-api/2.0.6/maven-plugin-
 api-2.0.6.pom
- Execution default-resources of goal org.apache.maven.plugins:maven-resources-plugin:2.4.3:resources failed: Plugin 
 org.apache.maven.plugins:maven-resources-plugin:2.4.3 or one of its dependencies could not be resolved: Failed to collect 
 dependencies for org.apache.maven.plugins:maven-resources-plugin:jar:2.4.3 () (org.apache.maven.plugins:maven-resources-
 plugin:2.4.3:resources:default-resources:process-resources)
- Plugin execution not covered by lifecycle configuration: org.apache.maven.plugins:maven-compiler-plugin:
 2.3.2:testCompile (execution: default-testCompile, phase: test-compile)

My pom file is the following:

<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>
   <groupId>com.lala.sarasa</groupId>
   <artifactId>msrdecision</artifactId>
  <packaging>war</packaging>
  <version>1.0-SNAPSHOT</version>
  <name>msrdecision Maven Webapp</name>
  <url>http://maven.apache.org</url>
 <dependencies>
   <dependency>
     <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
  </dependencies>
  <build>
    <finalName>hello</finalName>
   </build>
 </project>

Any idea?

Answer 1

I had same problem with Eclipse 3.7.2 (Indigo) and maven 3.0.4.

In my case, the problem was caused by missing maven-resources-plugin-2.4.3.jar in {user.home}.m2 epositoryorgapachemavenpluginsmaven-resources-plugin2.4.3 folder. (no idea why maven didn't update it)

Solution:

1.) add dependency to pom.xml

<dependency>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-resources-plugin</artifactId>
    <version>2.4.3</version>
</dependency>

2.) run mvn install from Eclipse or from command line

3.) refresh the project in eclipse (F5)

4.) run Maven > Update Project Configuration... on project (right click)

JAR file is downloaded to local repository and there are no errors in WS.