读入字符串，遇到某一字符结束读入

/**
* 读入字符串，遇到某一字符结束读入
* int.txt: 中国123美国abc日本;123
*/
import java.io.*;
class Test
{
public static void main(String[] args) throws IOException
{
FileReader in = new FileReader("in.txt");
int c;
StringBuffer sb = new StringBuffer();
c = in.read();
while( (c != ';') && (c != -1) )
{
sb.append((char)c);
c = in.read();
}
System.out.println(sb);
in.close();
}
}