list<obj>提取int类型进行计算

 1 /**
 2      * Statistics测试.
 3      *
 4      * @param streamBeanList
 5      */
 6     public void testStatistics(List<StreamBean> streamBeanList) {
 7  
 8         IntSummaryStatistics intSummaryStatistics = streamBeanList.stream().mapToInt(x -> x.getAge()).summaryStatistics();
 9  
10         System.out.println("年龄最大的是：" + intSummaryStatistics.getMax());
11         System.out.println("年龄最小的是：" + intSummaryStatistics.getMin());
12         System.out.println("年龄总和是：" + intSummaryStatistics.getSum());
13         System.out.println("平均年龄是：" + intSummaryStatistics.getAverage());
14         System.out.println("人数总和是：" + intSummaryStatistics.getCount());
15  
16  
17     }