Sonatype

 Log
    public abstract boolean isDebugEnabled();
    public abstract boolean isInfoEnabled();
    public abstract boolean isWarnEnabled();
    public abstract boolean isErrorEnabled();
    public abstract void debug(CharSequence charsequence);
    public abstract void debug(CharSequence charsequence, Throwable throwable);
    public abstract void debug(Throwable throwable);
    public abstract void info(CharSequence charsequence);
    public abstract void info(CharSequence charsequence, Throwable throwable);
    public abstract void info(Throwable throwable);
    public abstract void warn(CharSequence charsequence);
    public abstract void warn(CharSequence charsequence, Throwable throwable);
    public abstract void warn(Throwable throwable);
    public abstract void error(CharSequence charsequence);
    public abstract void error(CharSequence charsequence, Throwable throwable);
    public abstract void error(Throwable throwable);

  Mojo
    public abstract void execute() throws MojoExecutionException, MojoFailureException;
        public abstract Log getLog();

  AbstractMojo
    public Log getLog();
    public Map getPluginContext();

 MojoExecutionException

 MojoFailureException