利用springmvc处理模型数据

// 视图 可以传字符串(视图名字)也可以传View对象
private Object view;
// 数据模型 本质是一个map
private ModelMap model;

// 设置视图
public void setViewName(String viewName) {
 this.view = viewName;
}
// 获取视图
public String getViewName() {
 return this.view instanceof String ? (String)this.view : null;
}

// 获取数据模型
protected Map<String, Object> getModelInternal() {
 return this.model;
}

public ModelMap getModelMap() {
 if (this.model == null) {
 this.model = new ModelMap();
 }

 return this.model;
}

public Map<String, Object> getModel() {
 return this.getModelMap();
}

// 添加视图模型
public ModelAndView addObject(String attributeName, Object attributeValue) {
 this.getModelMap().addAttribute(attributeName, attributeValue);
 return this;
}

@RequestMapping("/modelAndViewTest")
public ModelAndView modelAndViewTest(){
 // 视图名
 ModelAndView modelAndView = new ModelAndView("modelAndViewTest");
 // 包含的数据
 modelAndView.addObject("dateTime",new Date());
 return modelAndView;
}

@RequestMapping("/mapTest")
public String mapTest(Map<String,String> map){
 System.out.println(map.getClass()); //class org.springframework.validation.support.BindingAwareModelMap
 map.put("name","张三");
 return "hello";
}

@Controller
@RequestMapping("helloWorld")
// 设置name属性共享
@SessionAttributes(value={"name"})
public class HelloWorldController {

 @RequestMapping("/mapTest")
 public String mapTest(Map<String,String> map){
 System.out.println(map.getClass()); //class org.springframework.validation.support.BindingAwareModelMap
 map.put("name","张三");
 return "hello";
 }

 // 可以在该方法中获取到name值为张三
 @RequestMapping("/sessionAttributes")
 public String sessionAttributes(HttpSession session){
 System.out.println(session.getAttribute("name"));
 return "hello";
 }
}

package com.yiidian.controller;

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;


@Controller
public class ModelAttributeController {
  
  //没有返回值的情况
  @ModelAttribute
  public void myModel(@RequestParam(required = false) String name, Model model) {
    model.addAttribute("name", name);
  }

  @RequestMapping(value = "/model")
  public String model() {
    return "success";
  }
}

package com.yiidian.controller;

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;


@Controller
public class ModelAttributeController {

  /**
   * 带返回值的情况
   * @param name
   */
  @ModelAttribute("name")
  public String myModel(@RequestParam(required = false) String name) {
    return name;
  }

  @RequestMapping(value = "/model")
  public String model() {
    return "success";
  }
}

@ModelAttribute("name")
public String myModel(@RequestParam(required = false) String name) {
  return name;
}

//应用在方法的参数行
@RequestMapping(value = "/model")
public String model(@ModelAttribute("name") String name) {
  System.out.println("name="+name);
  return "success";
}