我的 Maven 配置有什么问题?

I want to checkout sonar, so I added the following snippet to my pom.xml the dependency part was taken from http://maven.apache.org/general.html#tools-jar-dependency

<profile>
     <id>sonar</id>
     <activation>
        <activeByDefault>true</activeByDefault>
     </activation>
     <properties>
       <sonar.jdbc.url>jdbc:derby://localhost:1527/sonar;create=true</sonar.jdbc.url>
       <sonar.jdbc.driverClassName>org.apache.derby.jdbc.ClientDriver
       </sonar.jdbc.driverClassName>
       <sonar.jdbc.username>sonar</sonar.jdbc.username>
       <sonar.jdbc.password>sonar</sonar.jdbc.password>
       <sonar.host.url>http://localhost:8080/sonar</sonar.host.url>
     </properties>
     <dependencies>
    <dependency>
    <groupId>com.sun</groupId>
    <artifactId>tools</artifactId>
    <version>1.4.2</version>
    <scope>system</scope>
    <systemPath>${java.home}/../lib/tools.jar</systemPath>
    </dependency>
      </dependencies>
</profile>

Unfortunatly the error persists

Embedded error: Missing:
----------
1) com.sun:tools:jar:1.4.2

  Try downloading the file manually from the project website.

  Then, install it using the command: 
      mvn install:install-file -DgroupId=com.sun -DartifactId=tools -Dversion=1.4.2 -Dpackaging=jar -Dfile=/path/to/file

I also followed the suggestion to add the missing jar manually to the repository, which had no effect.

mvn install:install-file -DgroupId=com.sun -DartifactId=tools -Dversion=1.4.2 -Dpackaging=jar -Dfile=$JAVA_HOME/lib/tools.jar

What am I doing wrong?

EDIT:

I verified that tools.jar has been added to my local repository. In debug mode maven shows the error:

1 required artifact is missing.

for artifact: 
  group:artifact:war:1.0.0-BUILD-SNAPSHOT

from the specified remote repositories:
  central (http://repo1.maven.org/maven2)

解决方案

Are you running this in eclipse? If the answer is yes, this is an annoying and very misunderstood problem. Take a look at my answer here

You may not be pointing eclipse to the right jre/jdk when you're starting up (this is something you didn't necessarily configure rather was Windows)