笔记之_Java的jsp页面全局变量

servlet写法：
import java.util.HashMap;
import java.util.Map;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
public class InitSystemVariableServlet extends HttpServlet {
    private ServletContext  servletContext;
    private   Map<String, Object>  allMap=new HashMap<String, Object>();
    @Override
    public void init() throws ServletException {
        servletContext= super.getServletContext();  //全局的application
        allMap.put("systemTitle", "后台管理系统");
        allMap.put("systemName", "教务管理系统");
        //只要是页面用的往里面加
        servletContext.setAttribute("baseMap", allMap);
    }
}
web.xml配置：
<servlet>
    <servlet-name>BaseApplication</servlet-name>
    <servlet-class>com.wisezone.controller.InitSystemVariableServlet</servlet-class>
    <load-on-startup>3</load-on-startup>
</servlet>
取值直接用el表达式：
<title>${baseMap["systemTitle"] }</title>
Freemarker数字超过3位会格式化，取消格式化用：
<input type="text" value="${salary?string('#.00')}" name="salary"  />