关于一些前端框架ICON加载方式的疑惑

Question

最近写项目 用的是微信的UI库 不过 在我看他们的css的源码的时候 发现 他们的ICON根本就没加载图片 但是 图片却活生生的显示了出来 在用F12 DEBUG的时候 也在网络里 根本看不到图片的引用 很奇异 这是怎么实现的呢 具体代码如下

 .weui_icon_download:before {
    content: "\EA02"
}

.weui_icon_info:before {
    content: "\EA03"
}

.weui_icon_safe_success:before {
    content: "\EA04"
}

.weui_icon_safe_warn:before {
    content: "\EA05"
}

.weui_icon_success:before {
    content: "\EA06"
}

.weui_icon_success_circle:before {
    content: "\EA07"
}

Answer 1

package com.oracle.servlet;

import java.io.IOException;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.oracle.domain.Book;
import com.oracle.domain.Category;
import com.oracle.service.BaseServlet;
import com.oracle.service.BookService;
import com.oracle.service.CategoryService;

public class BookServlet extends BaseServlet {
BookService bookService=new BookService();
public String findAll(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
List booklist = bookService.findAll();
request.setAttribute("booklist", booklist);
return "f:/jsps/book/list.jsp";
}
public String findByCid(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String cid = request.getParameter("cid");
List booklist = bookService.findByCid(cid);
request.setAttribute("booklist", booklist);
return "f:/jsps/book/list.jsp";
}

public String findByBid(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {
    String bid = request.getParameter("bid");
     Book book = bookService.findByBid(bid);
     System.out.println(book);
    request.setAttribute("book", book);
    return "f:/jsps/book/desc.jsp";
}

}