SpringMVC基础

admin2024-05-15  0

目录

一:什么是SpringMVC

二:SpringMVC快速入门

1.导入依赖

2.创建核心配置类

3.创建controller关键类

4.创建访问的资源

5.配置tomcat

6.浏览器测试

7.解决中文乱码问题:

  三:测试工具:Postman

1.软件介绍:

2.测试请求数据

 Get请求:

2.1:普通参数—参数名相同

 2.2参数为字符串数组

2.3参数为字符串集合

2.4日期类型

Post请求:

2.5普通参数—参数名相同

2.6普通参数—参数名不同

2.7参数为实体类型

2.8参数为实体类型嵌套实体类

2.9JSON数组—字符串数组接收,集合接收

2.10JSON对象—实体类接收

2.11JSON对象数组—实体类集合接收

3.测试响应数据

3.1POJO转JSON字符串

3.2POJO集合转JSON数组


 一:什么是SpringMVC

二:SpringMVC快速入门

1.导入依赖

创建Maven项目,并导入对应的jar包,在pom.xml文件中导入以下两个依赖

<dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>4.0.1</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>5.3.31</version>
        </dependency>

2.创建核心配置类

在src包下创建两个包,分别为config包和controller包

SpringMVC基础,第1张

在config包下创建SpringMvcConfig核心配置类 


import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.view.InternalResourceViewResolver;

@Configuration//表示为一个配置类
@ComponentScan("com.lcyy")//扫描包
public class SpringMvcConfig {

    //创建一个视图解析器到IOC容器中去
    @Bean
    public InternalResourceViewResolver internalResourceViewResolver(){
        InternalResourceViewResolver resolver = new InternalResourceViewResolver();
        //设置视图的前缀
        resolver.setPrefix("/pages/");
        //设置后缀
        resolver.setSuffix(".jsp");

        return resolver;
    }

    
}

在创建ServletConfig类

import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.context.support.AnnotationConfigWebApplicationContext;
import org.springframework.web.servlet.support.AbstractDispatcherServletInitializer;

public class ServletConfig extends AbstractDispatcherServletInitializer {
    //加载springmvc配置,放到IOC容器中去
    @Override
    protected WebApplicationContext createServletApplicationContext() {
        AnnotationConfigWebApplicationContext ctx = new AnnotationConfigWebApplicationContext();
        ctx.register(SpringMvcConfig.class);
        return ctx;

    }

    //配置tomcat需要接收到的哪些资源
    @Override
    protected String[] getServletMappings() {
        return new String[]{"/"};
    }

    //加载spring配置
    @Override
    protected WebApplicationContext createRootApplicationContext() {
        return null;
    }
}

3.创建controller关键类

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

@Controller
public class UserController {
    //访问的是视图
    @RequestMapping("/save")
    public String save(){
        return "success";
    }

    /**
     * @ResponseBody 添加这个注解表示为在视图显示json字符串
     * @return
     */
    @RequestMapping("/save2")
    @ResponseBody
    public String save2(){
        return "hello";
    }
}

4.创建访问的资源

在webapp下创建pages包,在包下创建名为:success.jsp的jsp文件

<%--
  Created by IntelliJ IDEA.
  User: 22818
  Date: 2024/5/12
  Time: 13:23
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
hello 我是Springmvc
</body>
</html>

5.配置tomcat

SpringMVC基础,第2张

6.浏览器测试

运行tomcat,在浏览器输入localhost:8080/save 和  localhost:8080/save2,对应的结果分别如下:

SpringMVC基础,第3张

SpringMVC基础,第4张

7.解决中文乱码问题:

在ServletConfig类下,重写getServletFilters()方法(此为过滤器),定义编码格式为utf-8

 /**
     * 解决中文乱码问题,使用过滤器(输入(服务器向外发送为输入))
     * @return
     */
    @Override
    protected Filter[] getServletFilters() {
        CharacterEncodingFilter filter = new CharacterEncodingFilter();
        //设置为utf-8
        filter.setEncoding("utf-8");
        //返回过滤器
        return new Filter[]{filter};
    }

  三:测试工具:Postman

1.软件介绍:

2.测试请求数据

 Get请求:

2.1:普通参数—参数名相同
/**
     * 普通参数--参数相同(get)
     * @param name
     * @param age
     * @return
     */
    @RequestMapping("/commonParam")
    @ResponseBody
    public String commonParam(String name,Integer age){
        System.out.println("name = " + name);
        System.out.println("age = " + age);
        return "success";
    }
 2.2参数为字符串数组
  /**
     * 参数为字符串数组(get请求)
     * @param hobby
     * @return
     */
    @RequestMapping("/arrayParam")
    @ResponseBody
    public String arrayParam(String[] hobby){
        //封装到数组里
        System.out.println("hobby = " + Arrays.toString(hobby));
        return "success";
    }
2.3参数为字符串集合
/**
     * 参数为字符串集合(get)需添加@RequestParam
     * @param hobby
     * @return
     */
    @RequestMapping("/listParam")
    @ResponseBody
    public String listParam(@RequestParam List<String> hobby){
        System.out.println("hobby = " + hobby);
        return "success";
    }
2.4日期类型
  /**
     * 日期格式
     * @param date
     * @param date1
     * @return
     */
    @RequestMapping("/dateParam")
    @ResponseBody
    public String dateParam(Date date,
                            @DateTimeFormat(pattern = "yyyy-MM-dd") Date date1)
    {
        System.out.println("date = " + date);
        System.out.println("date1 = " + date1);
        return "success";
    }

Post请求:

2.5普通参数—参数名相同
/**
     * 普通参数--参数相同(get)
     * @param name
     * @param age
     * @return
     */
    @RequestMapping("/commonParam")
    @ResponseBody
    public String commonParam(String name,Integer age){
        System.out.println("name = " + name);
        System.out.println("age = " + age);
        return "success";
    }
2.6普通参数—参数名不同
 /**
     * 普通参数--形参名不同,起别名
     * @param username
     * @param age
     * @return  返回给前端
     */
    @RequestMapping("/commonParamDifferentName")
    @ResponseBody
    public String commonParamDifferentName(@RequestParam("name") String username, Integer age){
        System.out.println("username = " + username);
        System.out.println("age = " + age);
        return "success";
    }
2.7参数为实体类型
 /**
     * 参数为pojo(实体类)类型(post)
     * @param u
     * @return 返回给前端
     */
    @RequestMapping("/pojoParam")
    @ResponseBody
    public String pojoParam(User u){
        //封装为了实体类
        System.out.println("user = " + u);
        return "success";
    }
2.8参数为实体类型嵌套实体类
 /**
     * pojo嵌套使用(post)
     * @param u
     * @return
     */
    @RequestMapping("/pojoContainPojoParam")
    @ResponseBody
    public String pojoContainPojoParam(User u){
        //封装为了实体类
        System.out.println("user = " + u);
        return "success";
    }
2.9JSON数组—字符串数组接收,集合接收
 /**
     * 理论上get请求可以发送json数据,但一般用post请求发送json数据
     * @param hobby
     * @return
     */
    @RequestMapping("/jsonArray")
    @ResponseBody
    public String jsonArray(@RequestBody List<String> hobby){
        System.out.println("hobby = " + hobby);
        return "success";
    }

 /**请求
     * JSON对象数组,用pojo实体集合接收
     * @param list
     * @return
     */
    @RequestMapping("/listPojoParamForJson")
    @ResponseBody
    public String listPojoParamForJson(@RequestBody List<User> list){
        System.out.println("list = " + list);
        return "success";
    }
2.10JSON对象—实体类接收
 /**
     * 请求
     * @param user
     * @return
     */
    @RequestMapping("/pojoParamForJson")
    @ResponseBody
    public String pojoParamForJson(@RequestBody User user){
        System.out.println("user = " + user);
        return "success";
    }
2.11JSON对象数组—实体类集合接收
/**请求
     * JSON对象数组,用pojo实体集合接收
     * @param list
     * @return
     */
    @RequestMapping("/listPojoParamForJson")
    @ResponseBody
    public String listPojoParamForJson(@RequestBody List<User> list){
        System.out.println("list = " + list);
        return "success";
    }

3.测试响应数据

3.1POJO转JSON字符串
/**
     * 响应:JSON转字符串,响应给前端
     * @param user
     * @return
     */
    @RequestMapping("/toJson")
    @ResponseBody
    public User toJson(User user){
        User user1 = new User();
        user1.setName("张三");
        user1.setAge(18);
        user1.setAddress(new Address("广州省·","深圳市"));
        return user1;
    }
3.2POJO集合转JSON数组
 /**响应
     *pojo集合转json数组
     * @param
     * @return
     */
    @RequestMapping("/toJsonList")
    @ResponseBody
    public List<User> toJsonList(){
        List<User> users = new ArrayList<>();
        User user1 = new User();
        User user = user1;
        user.setName("张三");
        user.setAge(25);
        user.setAddress(new Address("陕西省","西安市"));

        User user2 = new User();
        user2.setName("李四");
        user2.setAge(20);
        user2.setAddress(new Address("陕西省","安康市"));

        User user3 = new User();
        user3.setName("李非");
        user3.setAge(21);
        user3.setAddress(new Address("陕西省","汉中市"));

        users.add(user);
        users.add(user2);
        users.add(user3);
        return users;
    }
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