IO流之自定义缓冲流

package day20.test;import java.io.IOException;import java.io.Reader;public class MyBuffered {private Reader r;public MyBuffered(Reader r) {this.r = r;}public String readLine() throws IOException {StringBuilder sb = new StringBuilder();int ch = 0;while((ch=r.read())!=-1) {if (ch=='\r') {continue;}if (ch=='\n') {return sb.toString();} else {sb.append((char)ch);}}//当文件读完时将会返回-1，那么这个方法会返回null，所以最后一行数据并没有进行返回//因此，我们进行判断，如果sb的长度不为0，就进行返回sb的值if (sb.length()>0) {return sb.toString();}return null;}public void close() throws IOException {r.close();}}