问题描述：
文章的字符统计
HEFEI－At age four, Ji Tingqiao could remember the names of all the bones of a skeleton. In primary school, he could understand heavy ancient Chinese classics. At 15, this September, he started university.
Across China, gifted students over the past 40 years have been enrolled in a special program set up in the University of Science and Technology of China.
统计上面这篇文章，每个英文字符出现的次数
思路：
最近学习了map类的HashMaple类，因为字符串是无序的，所以想利用利用映射关系，将映射相同的KEY对应的值统计出来；
由于是要求统计英文字符，所以在统计（参数传递）之前，将字符串中的所有大小写英文字符分割出来；
代码测试
public class tongji1 {
public static void Hashway ( String str) {
char[] a=str.toCharArray();
HashMap <Character,Integer> s=new HashMap();
for(char c: a) {
if(!s.containsKey(c)) {
s.put(c, 1);
}else {
s.put(c, s.get(c)+1);
}
}
for(Character key:s.keySet())
System.out.println(key+"在文章中出现的次数"+s.get(key));
}
public static void main(String[] args) {
String str="HEFEI－At age four, Ji Tingqiao could remember the names of all the bones of a skeleton. In primary school, he could understand heavy ancient Chinese classics. At 15, this September, he started university.\r\n" +
"Across China, gifted students over the past 40 years have been enrolled in a special program set up in the University of Science and Technology of China." ;
String astr=null;
char []b=str.toCharArray();
for(int i=0;i<str.length();i++) {
if((b[i]>='a'&&b[i]<='z')||(b[i]>='A'&&b[i]<='Z')) {
astr+=b[i];
}
}
Hashway(astr); //调用方法
}
}