1 /**
2 * The read4 API is defined in the parent class Reader4.
3 * int read4(char[] buf4);
4 */
5
6 public class Solution extends Reader4 {
7 /**
8 * @param buf Destination buffer
9 * @param n Number of characters to read
10 * @return The number of actual characters read
11 */
12 public int read(char[] buf, int n) {
13 int ans = 0;
14 char[] buf4 = new char[4];//目标缓存区
15 int size = read4(buf4);
16 while(size>0&&ans<n){
17 //size>0指的是文件还有剩余的字符
18 //ans<n意思就是目前的长度不超过n
19 for(int i=0;i<size&&ans<n;++i){
20 buf[ans++] = buf4[i];
21 }
22 size = read4(buf4);
23 }
24 return ans;
25 }
26 }
