Why did China fly 'combat patrols' over the Spratly Islands?

In the wake of an international court's ruling rejecting China's claims to disputed territory in the South China Sea, China said the combat exercises were an effort to protect its 'maritime interests.'
http://www.csmonitor.com/World/Asia-...pratly-Islands

Satellite photographs taken in late July show China appears to have built reinforced aircraft hangars on its holdings in disputed South China Sea islands, a Washington-based research group said.

The hangars on Fiery Cross, Subi and Mischief Reefs in the Spratly islands have room for any fighter jet in the Chinese air force, the Center for Strategic and International Studies (CSIS) said in a report on the photographs.

The images have emerged about a month after an international court in The Hague ruled against China's claims in the resource-rich area, a decision rejected by Beijing. China claims most of the South China Sea, through which $5 trillion in ship-borne trade passes every year. The Philippines, Vietnam, Malaysia, Taiwan and Brunei have overlapping claims.
http://www.reuters.com/article/us-so...-idUSKCN10K08P

Vietnam has discreetly fortified several of its islands in the disputed South China Sea with new mobile rocket launchers capable of striking China's runways and military installations across the vital trade route, according to Western officials.

Diplomats and military officers told Reuters that intelligence shows Hanoi has shipped the launchers from the Vietnamese mainland into position on five bases in the Spratly islands in recent months, a move likely to raise tensions with Beijing
http://www.reuters.com/article/us-so...-idUSKCN10K2NE