String sql="select a,b,c from abc where id=1 order by id desc";
        String regex="\\bfrom\\s*\\S*";
        Pattern p=Pattern.compile(regex);
        Matcher m=p.matcher(sql);
        if(m.find()){
            String table=m.group().replace("from","");
            System.out.println(""+table.trim());
        }else{
            System.out.println("not found");
        }

------解决方案--------------------
            String str="select a,b,c from abc where id=1 order by id desc";
		Pattern p=Pattern.compile("(.*from\\s)(\\w*)(.*)");
		Matcher m=p.matcher(str);
		if(m.find()){
			System.out.println(m.group(2));
		}else{
			System.out.println("false");
		}