SpringMVC18_SpringMVC获得请求数据5

一、获得请求参数-请求参数类型

 客户端请求参数的格式是: name=value&name=value...... 

 服务器端要获得请求的参数,有时还需要进行数据的封装,SpringMVC可以接收如下类型的参数:

  • 基本类型参数
  • POJO类型参数:简单java bean
  • 数组类型参数
  • 集合类型参数

二、获得请求参数-获得基本类型参数

 Controller中的业务方法的参数名称要与请求参数的name一致,参数值会自动映射匹配。并且能自动做类型转换;

 自动的类型转换是指从String向其他类型的转换

http://localhost:8080/itheima_springmvc1/quick9?username=zhangsan&age=12

 这表示Controller的业务方法中有两个参数-形参:username和age。

package com.itheima.controller;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.itheima.domain.User;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@Controller
@RequestMapping("/user")
public class UserController {

    @RequestMapping(value="/quick11")
    @ResponseBody
    public void save11(String username,int age) {
        System.out.println(username);
        System.out.println(age);
    }
}

  浏览器访问localhost:8080/user/quick11?username=zhangsan&age=18,检查控制台结果:

  

三、获得请求参数-获得POJO类型参数

 Controller中的业务方法的POJO参数的属性名请求参数的name一致,参数值会自动映射匹配。

package com.itheima.domain;

public class User {

    private String username;
    private int age;

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    @Override
    public String toString() {
        return "User{" +
                "username='" + username + '\'' +
                ", age=" + age +
                '}';
    }
}
package com.itheima.controller;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.itheima.domain.User;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@Controller
@RequestMapping("/user")
public class UserController {

    @RequestMapping(value="/quick12")
    @ResponseBody
    public void save12(User user) {
        System.out.println(user);
    }
}

  浏览器访问localhost:8080/user/quick12?username=lisi&age=20,检查控制台结果:

  

  浏览器访问localhost:8080/user/quick12?username=lisi,检查控制台结果:

  

四、获得请求参数-获得数组类型参数

 Controller中的业务方法数组名称与请求参数的name一致,参数值会自动映射匹配。

package com.itheima.controller;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.itheima.domain.User;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.Arrays;

@Controller
@RequestMapping("/user")
public class UserController {

    @RequestMapping(value="/quick13")
    @ResponseBody
    public void save13(String[] strs) {
        System.out.println(Arrays.asList(strs));
    
}

  浏览器访问http://localhost:8080/user/quick13?strs=aaa&strs=bbb&strs=ccc,检查控制台结果:

  

五、获得请求参数-获得集合类型参数1

 获得集合参数时,要将集合参数包装到一个POJO中才可以。

package com.itheima.domain;

import java.util.List;

public class VO {
    private List<User> userList;

    public List<User> getUserList() {
        return userList;
    }

    public void setUserList(List<User> userList) {
        this.userList = userList;
    }

    @Override
    public String toString() {
        return "VO{" +
                "userList=" + userList +
                '}';
    }
}
package com.itheima.controller;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.itheima.domain.User;
import com.itheima.domain.VO;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.Arrays;

@Controller
@RequestMapping("/user")
public class UserController {

    @RequestMapping(value="/quick14")
    @ResponseBody
    public void save14(VO vo) {
        System.out.println(vo);
    }
}

 

 浏览器访问http://localhost:8080/form.jsp,检查浏览器显示,并输入对应的值提交

       

  提交后检查控制台输出:

   

六、获得请求参数-获得集合类型参数2

 当使用ajax提交时,可以指定contentType为json形式,那么在方法参数位置使用@RequestBody可以直接接收集合数据而无需使用POJO进行包装。

package com.itheima.controller;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.itheima.domain.User;
import com.itheima.domain.VO;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.Arrays;
import java.util.List;

@Controller
@RequestMapping("/user")
public class UserController {

    @RequestMapping(value="/quick15")
    @ResponseBody
    public void save15(@RequestBody List<User> userList) {
        System.out.println(userList);
    }
}

  拷贝jquery-3.3.1.js文件到webapp/js目录下,并在webapp目录下新建ajax.jsp

  

  浏览器访问http://localhost:8080/ajax.jsp,观察浏览器控制台报错:

  

  解决办法:编辑spring-mvc.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
                           http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd
                           http://www.springframework.org/schema/mvc https://www.springframework.org/schema/mvc/spring-mvc.xsd">

    <!--Controller的组件扫描-->
    <!--如果配置com.itheima则和spring扫重复了-->
    <context:component-scan base-package="com.itheima.controller"/>

    <!--配置内部资源视图解析器-->
    <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <!-- /jsp/success.jsp -->
        <property name="prefix" value="/jsp/"/>
        <property name="suffix" value=".jsp"/>
    </bean>

    <!-- mvc的注解驱动 -->
    <mvc:annotation-driven />

  <!-- 开放静态资源,mapping是访问服务端找资源的地址,location是具体资源的目录 --> <mvc:resources mapping="/js/**" location="/js/" /> </beans>

  再次浏览器访问http://localhost:8080/ajax.jsp,观察浏览器控制台不报错了,检查tomcat控制台结果:

   

七、获得请求参数-静态资源访问的开启

 当有静态资源需要加载时,比如jquery文件,通过谷歌开发者工具抓包发现,没有加载到jquery文件,原因是SpringMVC的前端控制器DispatcherServlet的url-pattern配置的是/,代表对所有的资源都进行过滤操作,我们可以通过以下两种方式指定放行静态资源:

  • 在spring-mvc.xml配置文件中指定放行的资源

   mapping是访问服务端匹配的地址如/js/jquery-3.3.1.js,location是具体资源的目录(webapp/js目录)

<mvc:resources mapping="/js/**" location="/js/" />
  • 使用<mvc:default-servlet-handler/>标签

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
                           http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd
                           http://www.springframework.org/schema/mvc https://www.springframework.org/schema/mvc/spring-mvc.xsd">

    <!--Controller的组件扫描-->
    <context:component-scan base-package="com.itheima.controller"/>

    <!--配置内部资源视图解析器-->
    <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <!-- /jsp/success.jsp -->
        <property name="prefix" value="/jsp/"/>
        <property name="suffix" value=".jsp"/>
    </bean>

    <!-- mvc的注解驱动 -->
    <mvc:annotation-driven />

<!--    <mvc:resources mapping="/js/**" location="/js/" />-->

    <!-- springmvc框架帮你匹配地址,找不到资源,交给原始容器tomcat找静态资源-->
    <mvc:default-servlet-handler />
</beans>

  浏览器访问http://localhost:8080/ajax.jsp,检查tomcat控制台输出List

  

八、获得请求参数-配置全局乱码过滤器

 当post请求时,数据会出现乱码,我们可以设置一个过滤器来进行编码的过滤。

 浏览器访问http://localhost:8080/form.jsp,输入中文username提交时,发现控制台输出乱码:

  

 解决办法:编辑web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
         version="4.0">

    <!-- 配置全局过滤的filter -->
    <filter>
        <filter-name>CharacterEncodingFilter</filter-name>
        <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
        <init-param>
            <param-name>encoding</param-name>
            <param-value>UTF-8</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>CharacterEncodingFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

    <!--配置SpringMVC的前端控制器-->
    <servlet>
        <servlet-name>DispatcherServlet</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:spring-mvc.xml</param-value>
        </init-param>
        <!--服务器启动时加载spring创建对象-->
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>DispatcherServlet</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>

    <!--全局初始化参数-->
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:applicationContext.xml</param-value>
    </context-param>

   <!--配置监听器-->
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>

    <servlet>
        <servlet-name>UserServlet</servlet-name>
        <servlet-class>com.itheima.web.UserServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>UserServlet</servlet-name>
        <!-- 浏览器访问路径 -->
        <url-pattern>/userServlet</url-pattern>
    </servlet-mapping>

</web-app>

  浏览器再次访问http://localhost:8080/form.jsp,输入中文username提交时,检查控制台输出:

  

九、获得请求参数-参数绑定注解@RequestParam

 当请求的参数名称与Controller的业务方法参数名称不一致时,就需要通过@RequestParam注解显示的绑定

 注解@RequestParam还有如下参数可以使用:

  • value:请求参数名称
  • required:此在指定的请求参数是否必须包括,默认是true,提交时如果没有此参数则报错
  • defaultValue:当没有指定请求参数时,则使用指定的默认值赋值
package com.itheima.controller;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.itheima.domain.User;
import com.itheima.domain.VO;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.Arrays;
import java.util.List;

@Controller
@RequestMapping("/user")
public class UserController {

    @RequestMapping(value="/quick16")
    @ResponseBody
    public void save16(String username) {
        System.out.println(username);
    }
}

  浏览器访问http://localhost:8080/user/quick16?username=zhangsan,观察控制台能正常输出,见下图

  浏览器访问http://localhost:8080/user/quick16?name=zhangsan,观察控制台不能正常输出zhangsan,见下图

   

  解决办法:

package com.itheima.controller;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.itheima.domain.User;
import com.itheima.domain.VO;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.Arrays;
import java.util.List;

@Controller
@RequestMapping("/user")
public class UserController {

    @RequestMapping(value="/quick16")
    @ResponseBody
    //@RequestParam(value = "name")可以简写成 @RequestParam("name")
    public void save16(@RequestParam(value = "name") String username) {
        System.out.println(username);
    }
}

  浏览器访问http://localhost:8080/user/quick16?name=zhangsan,观察控制台正常输出zhangsan。这时候就不能访问http://localhost:8080/user/quick16?username=zhangsan了会报错,因为name参数required默认是true。

      

package com.itheima.controller;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.itheima.domain.User;
import com.itheima.domain.VO;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.Arrays;
import java.util.List;

@Controller
@RequestMapping("/user")
public class UserController {

    @RequestMapping(value="/quick16")
    @ResponseBody
    //value不能省略
    public void save16(@RequestParam(value = "name",required = false") String username) {
        System.out.println(username);
    }
}

  这时候再访问http://localhost:8080/user/quick16?username=zhangsan就不报错了,tomcat控制台输出:null

package com.itheima.controller;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.itheima.domain.User;
import com.itheima.domain.VO;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.Arrays;
import java.util.List;

@Controller
@RequestMapping("/user")
public class UserController {

    @RequestMapping(value="/quick16")
    @ResponseBody
    public void save16(@RequestParam(value = "name",required = false,defaultValue = "wangwu") String username) {
        System.out.println(username);
    }
}

  这时候再访问http://localhost:8080/user/quick16?username=zhangsan,检查tomcat控制台输出:

   

十、获得请求参数-Restful风格的参数的获取

 Restful是一种软件架构风格、设计风格,而不是标准,只是提供了一组设计原则和约束条件。主要用于客户端和服务器交互类的软件,基于这个风格设计的软件可以更简洁,更有层次,更易于实现缓存机制等。

 Restful风格的请求是使用“url+请求方式”表示一次请求目的的,HTTP 协议里面四个表示操作方式的动词如下:

  • GET:用于获取资源 
  • POST:用于新建资源 
  • PUT:用于更新资源 
  • DELETE:用于删除资源

 例如:

  • /user/1     GET :       得到id = 1 的 user
  • /user/1     DELETE:   删除id = 1 的 user
  • /user/1     PUT:        更新id = 1 的 user
  • /user        POST:      新增user

 上述url地址/user/1中的1就是要获得的请求参数,在SpringMVC中可以使用占位符进行参数绑定。地址/user/1可以写成/user/{id}占位符{id}对应的就是1的值。

 在业务方法中我们可以使用@PathVariable注解进行占位符的匹配获取工作。

 

package com.itheima.controller;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.itheima.domain.User;
import com.itheima.domain.VO;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.Arrays;
import java.util.List;

@Controller
@RequestMapping("/user")
public class UserController {

    //http://localhost:8080/user/quick19/zhangsan
    @RequestMapping(value="/quick19/{username}")
    @ResponseBody
    public void save19(@PathVariable(value = "username") String username) {
        System.out.println(username);
    }
}

  浏览器访问http://localhost:8080/user/quick19/zhangsan,检查控制台输出:

  

十一、获得请求参数-自定义类型转换器

  • SpringMVC默认已经提供了一些常用的类型转换器,例如客户端提交的字符串转换成int型进行参数设置。
  • 但是不是所有的数据类型都提供了转换器,没有提供的就需要自定义转换器,例如:日期类型的数据就需要自定义转换器。

 自定义类型转换器的开发步骤:
  1. 定义转换器类实现Converter接口
  2. 在spring-mvc.xml配置文件中声明转换器
  3. 在<annotation-driven>中引用转换器

 代码实现:

  1. 定义转换器类实现Converter接口

package com.itheima.converter;

import org.springframework.core.convert.converter.Converter;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;

public class DateConverter implements Converter<String, Date> {

    public Date convert(String dateStr) {
        //将日期字符串转换成日期对象 返回
        SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");
        Date date = null;
        try {
            date = format.parse(dateStr);
        } catch (ParseException e) {
            e.printStackTrace();
        }
        return date;
    }
}

  2. 在spring-mvc.xml配置文件中声明转换器

  3. 在<annotation-driven>中引用转换器

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
                           http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd
                           http://www.springframework.org/schema/mvc https://www.springframework.org/schema/mvc/spring-mvc.xsd">

    <!--Controller的组件扫描-->
    <context:component-scan base-package="com.itheima.controller"/>

    <!--配置内部资源视图解析器-->
    <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <!-- /jsp/success.jsp -->
        <property name="prefix" value="/jsp/"/>
        <property name="suffix" value=".jsp"/>
    </bean>

    <!-- mvc的注解驱动 -->
    <mvc:annotation-driven conversion-service="conversionService"/>

    <!-- springmvc框架帮你匹配地址,找不到资源,交给原始容器tomcat找静态资源-->
    <mvc:default-servlet-handler />

    <!--  声明转换器  -->
    <bean id="conversionService" class="org.springframework.context.support.ConversionServiceFactoryBean">
        <property name="converters">
            <list>
                <bean class="com.itheima.converter.DateConverter"/>
            </list>
        </property>
    </bean>

</beans>

 

package com.itheima.controller;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.itheima.domain.User;
import com.itheima.domain.VO;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.Arrays;
import java.util.Date;
import java.util.List;

@Controller
@RequestMapping("/user")
public class UserController {

    @RequestMapping(value="/quick20")
    @ResponseBody
    public void save20(Date date) {
        System.out.println(date);
    }
}

  浏览器访问http://localhost:8080/user/quick20?date=2018-12-21,检查控制台输出:

  

十二、获得请求参数-获得Servlet相关API

 SpringMVC支持使用原始ServletAPI对象作为控制器方法的参数进行注入,常用的对象如下: 

  • HttpServletRequest
  • HttpServletResponse
  • HttpSession
package com.itheima.controller;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.itheima.domain.User;
import com.itheima.domain.VO;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;
import java.util.Arrays;
import java.util.Date;
import java.util.List;

@Controller
@RequestMapping("/user")
public class UserController {

    @RequestMapping(value="/quick21")
    @ResponseBody
    public void save21(HttpServletRequest request, HttpServletResponse response, HttpSession session) {
        System.out.println(request);
        System.out.println(response);
        System.out.println(session);
    }
}

  浏览器访问http://localhost:8080/user/quick21,检查控制台输出:

   

十三、获得请求参数-获得请求头信息

 1. 使用@RequestHeader可以获得请求头信息,相当于web阶段学习的request.getHeader(name)

  @RequestHeader注解的属性如下:

  • value:请求头的名称
  • required:是否必须携带此请求头

  

package com.itheima.controller;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.itheima.domain.User;
import com.itheima.domain.VO;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;
import java.util.Arrays;
import java.util.Date;
import java.util.List;

@Controller
@RequestMapping("/user")
public class UserController {

    @RequestMapping(value="/quick23")
    @ResponseBody
  //浏览器访问地址时,从请求头里找到User-Agent字段的值赋给user_agent
public void save23(@RequestHeader(value = "User-Agent",required = false) String user_agent) { System.out.println(user_agent); } }

  浏览器访问http://localhost:8080/user/quick23,检查控制台输出:

  

 2. 使用@CookieValue可以获得指定Cookie的值

  @CookieValue注解的属性如下:

  • value:指定cookie的名称 
  • required:是否必须携带此cookie

  

package com.itheima.controller;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.itheima.domain.User;
import com.itheima.domain.VO;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;
import java.util.Arrays;
import java.util.Date;
import java.util.List;

@Controller
@RequestMapping("/user")
public class UserController {


    @RequestMapping(value="/quick24")
    @ResponseBody
    public void save24(@CookieValue(value = "JSESSIONID") String jsessionId){
        System.out.println(jsessionId);
    }
}

  浏览器访问http://localhost:8080/user/quick24,检查控制台输出:

  

 

posted on 2023-05-11 12:06  花溪月影  阅读(14)  评论(0编辑  收藏  举报