在Eclipse里初次使用Maven，右键project->add dependency, 发现search不管用，这时候需要按照以下步骤操作:
Goto "Preferences -> Maven"
Check "Download repository index updates on start" and restart your eclipse. And then, look at the progress view, an index file is downloading.
After downloading completely, your artifacts search feature is ready to use.
UPDATE You also need to rebuild your maven repository index in 'maven repository view'.
In this view , open 'Global Repositories', right-click 'central', check 'Full Index Enable', and then, click 'Rebuild Index' in the same menu.
A 66M index file will be downloaded. 