#emerge -Duva world

These are the packages that would be merged, in order:

Calculating world dependencies... done!
[ebuild  N    ] dev-java/java-config-1.2.11-r1  0 kB 
[ebuild  N    ] dev-java/blackdown-jdk-1.4.2.03-r2  USE="X alsa -browserplugin -doc -mozilla -nsplugin" 0 kB 
[ebuild  N    ] virtual/jdk-1.4.2  0 kB 
[ebuild  N    ] virtual/jre-1.4.2  0 kB 

Total size of downloads: 0 kB

Would you like to merge these packages? [Yes/No]