1 //前提为a、b均不能为null
 2 if(a.compareTo(b) == -1){
 3     System.out.println("a小于b");
 4 }
 5  
 6 if(a.compareTo(b) == 0){
 7     System.out.println("a等于b");
 8 }
 9  
10 if(a.compareTo(b) == 1){
11     System.out.println("a大于b");
12 }
13  
14 if(a.compareTo(b) > -1){
15     System.out.println("a大于等于b");
16 }
17  
18 if(a.compareTo(b) < 1){
19     System.out.println("a小于等于b");
20 }