java得到键盘录入，并返回大写，输入over则终止输入

public static void main(String[] args) throws IOException {
readKey_2();
}

/*
 * 得到键盘录入，并返回大写，输出over则停止
 */
public static void readKey_2() throws IOException {

//接收容器
StringBuilder sb = new StringBuilder();

InputStream in = System.in;
int ch = 0;
while((ch=in.read())!=-1){
if(ch=='\r')
continue;
if(ch=='\n'){
String temp = sb.toString();
if(temp.equals("over"))
break;
System.out.println(temp.toUpperCase());
sb.delete(0, sb.length());
}else
sb.append((char)ch);
}
}