3.SpringMVC响应

package com.gzcgxt.erp;

import java.io.IOException;

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

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;

@Controller
@RequestMapping("/hello")
/**
 * 
 * <p>Title: HelloController</p>
 * <p>Description: springMVC响应处理</p>
 * <p>Company: www.baidu.com</p> 
 * @author    刘诗华 微信:15390725037
 * @date    2019-7-16下午3:12:27
 * @version 1.0
 */
public class HelloController {
    
    /**
     * 1.经过Http对象
     * <p>Title: index</p>
     * <p>Description: </p>
     * @return
     */
    public void httpBean(HttpServletRequest request,
            HttpServletResponse response) throws ServletException, Exception {
        request.setAttribute("name", "刘诗华");
        
        //请求转发
        request.getRequestDispatcher("/test").forward(request, response);
        
        //请求重定向
        response.sendRedirect("/test");
    }
    
    /**
     * 2.经过 ModelAndView来返回响应
     * <p>Title: index</p>
     * <p>Description: </p>
     * @return
     */
    @RequestMapping("/index")
    public ModelAndView index()
    {
        ModelAndView mv=new ModelAndView();
        mv.setViewName("index");
        mv.addObject("name","刘诗华");
        return mv;
    }
    
    /**
     * 3.返回String字符串,这里要借助 Model model这个接口来绑定数据响应
     * <p>Title: getString</p>
     * <p>Description: </p>
     * @return
     */
    @RequestMapping("/getString")
    public String getString(Model m)
    {
        m.addAttribute("name","刘诗华");
        //存放一个String类型的数据
        //则在前台显示　${string} 数据类型小写
        m.addAttribute("Hello My name is lsh");
        return "getString";
    }
　　
　　//第四种 返回json对象

     @RequestMapping("/index")
     @ResponseBody

   public User getUser()   {　　　　return new User(100,"lsh","123456");　　}
}