SpringMvc（2）

1.接受的参数为日期类型

2.controller进行数据保存

3. 静态资源的映射关系

4.Springmvc 完成ajax功能

（1）接收的参数为日期类型

　　使用Controller注解的类在接收参数时如果参数为时间类型的参数时会报错：表示请求的参数有问题

　解决方法（1）：在对应的Controller类中加入如下代码表示：当接收的参数为日期类型时先经过该方法进行处理。适合接收单个日期参数

@InitBinder
    public void initBinder(ServletRequestDataBinder binder){
        //只要网页中传来的数据格式为yyyy-MM-dd 就会转化为Date类型
        binder.registerCustomEditor(Date.class, new CustomDateEditor(new SimpleDateFormat("yyyy-MM-dd"),//模式可以更改
                true));
    }

解决方案（2）：当接收的参数比较多时（接收的是一个对象）

@RequestMapping("/list.do")
    public String list(User user) {
        System.out.println(user);
        return "index";
    }

参数有上图几个，这时为了避免报错400，我们可以在该实体类的Date属性中加入@DateTimeFormat(pattern="yyyy-MM-dd")注解适合用于实体类中

（2）controller 进行数据保存

　　2.1 数据保存到request作用域的方式.　　　

　　　　1. 使用ModelAndView，那么该方法的返回类型必须是ModelAndView

package com.zhiyou100.ydb.controller;

import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;

import org.springframework.beans.propertyeditors.CustomDateEditor;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.ServletRequestDataBinder;
import org.springframework.web.bind.annotation.InitBinder;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.SessionAttributes;
import org.springframework.web.servlet.ModelAndView;

import com.zhiyou100.ydb.bean.User;

@Controller
@RequestMapping("/user")
@SessionAttributes(names={"name"})
public class UserController {
//    使用ModelAndView 将数据保存到request
    @RequestMapping("/mod.do")
    public ModelAndView Mod() {
        ModelAndView mv =new ModelAndView("index");
        mv.addObject("name", "张三");
        return mv;
    }
}

测试：

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
${requestScope.name }
<img src="/springmvc-03/img/1.jpeg" height="700px">
</body>
</html>

　　　　2. 使用Model, 方法的返回值还是字符串类型。

package com.zhiyou100.ydb.controller;

import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;

import org.springframework.beans.propertyeditors.CustomDateEditor;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.ServletRequestDataBinder;
import org.springframework.web.bind.annotation.InitBinder;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.SessionAttributes;
import org.springframework.web.servlet.ModelAndView;

import com.zhiyou100.ydb.bean.User;

@Controller
@RequestMapping("/user")
@SessionAttributes(names={"name"})
public class UserController {
       // 使用Model 将数据保存到request
      @RequestMapping("/mode.do")
       public String Mode(Model mdoel) {
             mdoel.addAttribute("name", "李四");

                return "index";
      }
}

　测试

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
${requestScope.name }
<img src="/springmvc-03/img/1.jpeg" height="700px">
</body>
</html>

　　　　3. 使用Map.方法的返回值还是字符串类型。

package com.zhiyou100.ydb.controller;

import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;

import org.springframework.beans.propertyeditors.CustomDateEditor;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.ServletRequestDataBinder;
import org.springframework.web.bind.annotation.InitBinder;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.SessionAttributes;
import org.springframework.web.servlet.ModelAndView;

import com.zhiyou100.ydb.bean.User;

@Controller
@RequestMapping("/user")
@SessionAttributes(names={"name"})
public class UserController {
     //    使用Map 将数据保存到request
    @RequestMapping("map.do")
    public String Setmap(Map<String, Object> map) {
        map.put("name", "王五");
        return "index";
    }
}

测试

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
${requestScope.name }
<img src="/springmvc-03/img/1.jpeg" height="700px">
</body>
</html>

　　4. 原始的HttpServletRequest对象保存

package com.zhiyou100.ydb.controller;

import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;

import org.springframework.beans.propertyeditors.CustomDateEditor;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.ServletRequestDataBinder;
import org.springframework.web.bind.annotation.InitBinder;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.SessionAttributes;
import org.springframework.web.servlet.ModelAndView;

import com.zhiyou100.ydb.bean.User;

@Controller
@RequestMapping("/user")
@SessionAttributes(names={"name"})
public class UserController {
   //    使用原始 HttpServletRequest 将数据保存到request
    @RequestMapping("req.do")
    public String Setmap(HttpServletRequest request) {
        request.setAttribute("name", "刘六");
        return "index";
    }
}

测试：

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
${requestScope.name }
<img src="/springmvc-03/img/1.jpeg" height="700px">
</body>
</html>

　　2.2数据保存到session作用域的方式.

使用原始的HttpSession保存。

package com.zhiyou100.ydb.controller;

import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;

import org.springframework.beans.propertyeditors.CustomDateEditor;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.ServletRequestDataBinder;
import org.springframework.web.bind.annotation.InitBinder;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.SessionAttributes;
import org.springframework.web.servlet.ModelAndView;

import com.zhiyou100.ydb.bean.User;

@Controller
@RequestMapping("/user")
@SessionAttributes(names={"name"})
public class UserController {
 //    使用原始 HttpSession 将数据保存到Session
    @RequestMapping("ses.do")
    public String Setmap(HttpSession session) {
        session.setAttribute("name", "赵七");
        return "index";
    }
}

测试：

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
${sessionScope.name }
<img src="/springmvc-03/img/1.jpeg" height="700px">
</body>
</html>

　　　2.使用注解@SessionAttributes(name={key1,key2})

package com.zhiyou100.ydb.controller;

import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;

import org.springframework.beans.propertyeditors.CustomDateEditor;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.ServletRequestDataBinder;
import org.springframework.web.bind.annotation.InitBinder;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.SessionAttributes;
import org.springframework.web.servlet.ModelAndView;

import com.zhiyou100.ydb.bean.User;

@Controller
@RequestMapping("/user")
@SessionAttributes(names={"name"})//键名叫：name的保存的作用域为session
public class UserController {
//    使用注解 将数据保存到request
    @RequestMapping("/sess.do")
    public String Mode(Model mdoel) {
        mdoel.addAttribute("name", "李四");
        return "index";
    }
}

测试：

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
${sessionScope.name }
<img src="/springmvc-03/img/1.jpeg" height="700px">
</body>
</html>

　　　2.3保存到application中

package com.zhiyou100.ydb.controller;

import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;

import org.springframework.beans.propertyeditors.CustomDateEditor;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.ServletRequestDataBinder;
import org.springframework.web.bind.annotation.InitBinder;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.SessionAttributes;
import org.springframework.web.servlet.ModelAndView;

import com.zhiyou100.ydb.bean.User;

@Controller
@RequestMapping("/user")
@SessionAttributes(names={"name"})
public class UserController {
       // 使用Model 将数据保存到request
      @RequestMapping("/mode.do")
       public String Mode(Model mdoel,HttpSession session) {
             mdoel.addAttribute("name", "李四");
　　　　　　　　session.getServletContext().setAttribute("name","我在application中")
                return "index";
      }
}

测试：

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
${applicationScope.name }
<img src="/springmvc-03/img/1.jpeg" height="700px">
</body>
</html>

因为RequestMapping注解下的方法返回的默认为请求转发如何让其变成重定向呢？

解决方案 :加入redirect:

（3）静态资源的映射关系

当我们在jsp文件中引入img 图片，在用浏览器运行会出现找不到图片现象

1.首先配置任何请求都要经过DispatcherServlet

2.这时就需要使用静态资源映射在springmvc的配置文件中添加

　　（4）Springmvc完成ajax功能

　　　　　　1.加入Jackson的jar包和 jquery jar包

　　　　　2.引入js

　　　　　　3.在响应的方法上加 @ResponseBody : 表示把Java对象转化为json对象

@RequestMapping("Ajax1")
    @ResponseBody
    public String ajax1(String name) {
        System.out.println(name);
        return "你好";
    }

　　　　　　4.编写ajax方法

　　　　　　5.方法的返回类型可以是字符串，对象，集合

package com.zhiyou100.ydb.controller;

import java.util.ArrayList;
import java.util.List;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

import com.zhiyou100.ydb.bean.User;

@Controller
@RequestMapping(value="ajax", produces = "text/plain;charset=UTF-8")
public class AjaxController {
    
    @RequestMapping("Ajax1")
    @ResponseBody
    public String ajax1(String name) {
        System.out.println(name);
        return "你好";
    }
    @RequestMapping("Ajax2")
    @ResponseBody
    public User ajax2(String name) {
        User user = new User("张三",10);
        return user;
    }
    @RequestMapping("Ajax3")
    @ResponseBody
    public List<User> ajax3(String name) {
        User user1 = new User("张三",10);
        User user2 = new User("李四",10);
        User user3 = new User("王五",10);
        User user4 = new User("刘六",10);
        User user5 = new User("赵七",10);
        List<User> list = new ArrayList<>();
        list.add(user1);
        list.add(user2);
        list.add(user3);
        list.add(user4);
        list.add(user5);
        return list;
    }
    
    
}

（注意：）如果ajax返回的为字符串，那么就会出现乱码

　　　　因为在spring-webmvc 源码中返回的是字符串默认的格式是ISO--1

解决方案（1）：在springmvc 映射文件中加入

解决方案（2）：在RequestMapping的属性中添加返回数据类型属性 produces = "text/plain;charset=UTF-8"

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原文地址：https://www.cnblogs.com/Kuriyama-Mirai/p/11455767.html