Classroom Management Controller: Add, Edit, Delete & View Classrooms

package com.scq.controller;

import com.scq.beans.classroom; import com.scq.servlet.classroomServlet; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Controller; import org.springframework.ui.Model; import org.springframework.web.bind.annotation.RequestMapping;

import javax.servlet.http.HttpServletRequest; import java.util.ArrayList;

@Controller @RequestMapping("/class") public class classroomController { @Autowired classroomServlet classroomServlet;

@RequestMapping(value = "getAll.action")
public String getAll(Model model, HttpServletRequest req)throws Exception{
    System.out.println("aaa:"+req.getServletContext().getInitParameter("aaa"));
    ArrayList <classroom> classrooms= classroomServlet.getAll();
    model.addAllAttributes("classrooms",classrooms);
    return "classroomview";
}

@RequestMapping(value = "/add.action")
public String add(classroom classroom){
    classroomServlet.add(classroom);
    return "redirect:/class/getAll.action";

}

@RequestMapping(value = "delete.action")
public String delete(int id){
    classroomServlet.delete(id);
    return "redirect:/class/delete.action";
}


@RequestMapping(value = "addview.action")
public String addview(Model model){
    model.addAllAttributes("tag","add");
    return "classroomsave";
}

@RequestMapping(value = "/editview.action")
public String editview(Model model,int id){
    classroom classroom=classroomServlet.get(id);
    model.addAllAttributes("tag","edit");
    model.addAllAttributes("classroom",classroom);
    return "classroomsave";
}

@RequestMapping(value = "/edit.action")
public String edit(classroom classroom,Model model){
    classroomServlet.edit(classroom);
    return "redirect:/class/getAll.action";
}

}model为什么会无法解析括号内的方法内容：在classroomController的addview方法中，model.addAllAttributes()方法的使用是有错误的。这个方法应该接受两个参数，第一个参数是String类型的属性名称，第二个参数是属性值。所以正确的使用方式应该是model.addAttribute("tag", "add")。

修改后的代码如下：

@RequestMapping(value = "addview.action")
public String addview(Model model){
    model.addAttribute("tag", "add");
    return "classroomsave";
}