JAVA中出现的编译错误

package bytestream;

import java.io.IOException;
import java.io.InputStream;

public class ReadKeyTest2 {

/**
 * @param args
 * @throws IOException 
 */
public static void main(String[] args) throws IOException {
    // TODO Auto-generated method stub
    readKey2();
}

public static void readKey2() throws IOException {
    // TODO Auto-generated method stub

    InputStream in=System.in;

    StringBuilder sb=new StringBuilder();

    int ch=0;
    while((ch=in.read())!=-1)
    {
        if(ch=='r')
            continue;
        if(ch=='\n')
                           这里String s  下划线提示错误，不知道为什么
            String s=sb.toString        
              if("over".equals(s                                           {
                break;
            }
        else
            {
                 System.out.println(s.toUpperCase());

                sb.delete(0, sb.length());
            }
              else出现下划线错误
        else{
                sb.append((char)ch);
            }



    }
}

}

sb.toString();
没拷全？还是基本语法错误？