Oracle announced buying Sun on Apr 20, 2009.[1]
The deal may have taken a while to complete (as late as 2015), but Oracle got to integrate Sun's assets into Oracle as early as 2010, and indeed that is when everyone (including Oracle) believes Sun was acquired.
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0: http://i.i.cbsi.com/cnwk.1d/i/ne/pdfs/FINAL_Complaint.pdf
I don't know when Oracle bought Sun (didn't look it up), but this is not what the sentence(s) is(are) implying.
The lawsuit began when Oracle sued Google in 2010 over its use of 37 Java APIs, which Oracle acquired when it bought Sun Microsystems. In 2012, a judge ruled that APIs can't be copyrighted at all, but an appeals court disagreed.
Not sure what confusion could arise from this.