/**
* 截取指定长度的字符串，中文算2个长度，若过长，返回xxx...，否则返回原串
* @param s Original String.
* @param max Max length.
* @return Left part of string.
*/
public static String left(String s, int max) {
char[] cs = s.toCharArray();
int count = 0;
int last = cs.length;
for(int i=0; i<cs.length; i++) {
if(cs[i]>255)
count+=2;
else
count++;
if(count>max) {
last = i+1;
break;
}
}
if(count<=max) // string is short or just the size!
return s;
// string is too long:
max -= 3;
for(int i=last-1; i>=0; i--) {
if(cs[i]>255)
count-=2;
else
count--;
if(count<=max) {
return s.substring(0, i) + "...";
}
}
return "...";
}
