SpringMVC3——处理模型数据

//ModelAndView
@RequestMapping(value = "testModelAndView")
public ModelAndView testModelAndView(){ //既有数据又有视图
    ModelAndView mv=new ModelAndView("success");//view,/views/success.jsp
    Student student = new Student();
    student.setId(1);
    student.setName("zs");
    mv.addObject("student",student);//相当于request.setAtttribute
    return mv;
}

${requestScope.student.id}-${requestScope.student.name}<br/>

//ModelMap
@RequestMapping(value = "testModelMap")
public String testModelMap(ModelMap map){ //既有数据又有视图
    Student student = new Student();
    student.setId(1);
    student.setName("zs");
    map.put("student1",student);//request域
    return "success";//view
}

@SessionAttributes("student3,student")//如果要在request作用域中存放student4对象，则同时将该对象放入session作用域
@SessionAttributes(types = Student.class)//如果要在request作用域中存放student类型的对象，则同时将该类型的对象放入session作用域

//查询
@ModelAttribute //在任何请求前，都先执行@ModelAttribute修饰的方法
public void queryStudentById(Map<String,Object> map){
   //模拟调用三层查询数据库的操作
    Student student = new Student();
    student.setId(3);
    student.setName("zs");
    student.setAge(23);
    //map.put("student",student);//map的key就是与方法（testModelAttribute）参数类型的首字母的小写后一致
    map.put("stu",student);
}

//修改，ModelAttribute
@RequestMapping(value = "testModelAttribute")
public String testModelAttribute(@ModelAttribute("stu") Student student){ 
    student.setName(student.getName());//将名字修改为ls
    System.out.println(student.getId()+","+student.getName()+","+student.getAge());
    return "success";
}