从1亿个数字中取出最大的100个

import java.util.Random; 
import java.util.Set; 
import java.util.TreeSet; 

public class TestSF { 

public static Set<Integer> getTop100(int[] inputArray) { 

TreeSet<Integer> top100 = new TreeSet(); 
for (int i = 0; i < inputArray.length; i++) { 

if (top100.size()<100){ 
top100.add(inputArray[i]); 
}else if ((Integer)top100.first()<inputArray[i]){ 
Object obj = top100.first(); 
top100.remove(obj); 
top100.add(inputArray[i]); 
} 

} 

return top100; 

} 

public static void main(String[] args) { 

int numberCount = 100000000; 

int maxNumber = numberCount; 

int inputArray[] = new int[numberCount]; 

Random random = new Random(); 

for (int i = 0; i < numberCount; ++i) { 

inputArray[i] = Math.abs(random.nextInt(maxNumber)); 

} 

System.out.println("Sort begin..."); 

long current = System.currentTimeMillis(); 

Set<Integer> result = TestSF.getTop100(inputArray); 

System.out.println("Spend time:"+(System.currentTimeMillis() - current)); 


} 

}