import java.io.*;public class SystemInTest ...{ public static void main (String[] args) throws Exception ...{ BufferedReader in = new BufferedReader ( new InputStreamReader (System.in) ); String s = null; while(true) ...{ s = in.readLine(); System.out.println(s); } //in.close(); Error: "无法访问的语句" }} 起初看到这个错误,有点想不明白。上网查了一下,也没有明确的结果。后来仔细想了一下"无法访问的语句"是JVM无法访问吗?发现此句前面是一个死循环。原来如此。将上面的程序稍微修改一下就好了 import java.io.*;public class SystemInTest ...{ public static void main (String[] args) throws Exception ...{ BufferedReader in = new BufferedReader ( new InputStreamReader (System.in) ); String s = null; while(!(s = in.readLine()).equalsIgnoreCase("quit")) ...{ System.out.println(s); } in.close(); }}