2021-04-17

SpringMVC

1.SpringMVC的注解开发

1.创建项目

2.完善项目

3.导入依赖

4.配置web.xml

<!DOCTYPE web-app PUBLIC
 "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
 "http://java.sun.com/dtd/web-app_2_3.dtd" >
<web-app>
  <display-name>Archetype Created Web Application</display-name>
  <servlet>
    <servlet-name>dispatcherServle</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <init-param>
      <param-name>contextConfigLocation</param-name>
      <param-value>classpath:springmvc.xml</param-value>
    </init-param>
  </servlet>
  <servlet-mapping>
    <servlet-name>dispatcherServle</servlet-name>
    <url-pattern>*.do</url-pattern>
  </servlet-mapping>
</web-app>

5.配置SpringMVC配置文件

<?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:mvc="http://www.springframework.org/schema/mvc"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans.xsd
       http://www.springframework.org/schema/mvc
       http://www.springframework.org/schema/mvc/spring-mvc.xsd
        http://www.springframework.org/schema/context
       http://www.springframework.org/schema/context/spring-context.xsd">
    <!--开启注解-->
    <mvc:annotation-driven></mvc:annotation-driven>
    <!--配置自动扫描包-->
    <context:component-scan base-package="com.wangxing.springmvc.controller"></context:component-scan>
    <!--配置视图解析器-->
    <!--org.springframework.web.servlet.view.InternalResourceViewResolver-->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/"></property>
        <property name="suffix"  value=""></property>
    </bean>
</beans>

6.创建控制器

package com.wangxing.springmvc.controller;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;
@Controller
public class HelloController {
    @RequestMapping("/test1.do")
    public ModelAndView  testRequest(){
        ModelAndView  mav=new ModelAndView();
        mav.addObject("info","hello,网星软件");
        mav.setViewName("test.jsp");
        return  mav;
    }
}

7.创建jsp

8.配置服务部署项目

9.测试http://localhost:8080/spingmvc2/test1.do

扫描二维码关注公众号，回复： 13263458 查看本文章

2. @Controller注解

@Controller---表示我们所编写的java类是一个处理请求的控制器类。

              只能作用在java类。

              可以使用@Component去代替，在javaweb程序中是分层出来的为了表名java类是一个控制器，我们才使用@Controller

@Controller中包含有@Component。

@Controller与我们在spring中学习的@Service和@Repository将应用程序标记为不同的层。

数据访问层------@Repository

业务访问层------@Service

Web层【控制层】----@Controller

webapp------------静态资源

3. @RequestMapping

设置控制器类/请求处理方法的访问路径的

@RequestMapping可以作用在java类上，表示配置这个java类的访问路径；

package com.wangxing.springmvc.controller;
import org.springframework.stereotype.Controller;
import org.springframework.stereotype.Repository;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.servlet.ModelAndView;
@Controller
@RequestMapping("/hello")
public class HelloController{
    @RequestMapping("/test1.do")
    public ModelAndView  testRequest(){
        ModelAndView  mav=new ModelAndView();
        mav.addObject("info","hello,网星软件");
        mav.setViewName("test.jsp");
        return  mav;
    }
}

http://localhost:8080/spingmvc2/hello/test1.do

如果控制器类中没有@RequestMapping("/hello")，那么我们要访问请求处理方法就可以直接使用请求处理方法上@RequestMapping("/test1.do")的访问路径。

package com.wangxing.springmvc.controller;
import org.springframework.stereotype.Controller;
import org.springframework.stereotype.Repository;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.servlet.ModelAndView;
@Controller
public class HelloController{
    @RequestMapping("/test1.do")
    public ModelAndView  testRequest(){
        ModelAndView  mav=new ModelAndView();
        mav.addObject("info","hello,网星软件");
        mav.setViewName("test.jsp");
        return  mav;
    }
}

http://localhost:8080/spingmvc2/test1.do

@RequestMapping也可以作用在请求处理方法上，表示配置这个请求处理方法的访问路径。

@RequestMapping的常用的属性

1.value表示设置访问路径[可以省略]  

@RequestMapping(value = "/test1.do")

可以省略

@RequestMapping("/test1.do")

设置访问路径的时候可以设置通配符

 ？ ： 匹配任何单字符 

例如：@RequestMapping("/?hello.test")

http://localhost:8080/spingmvc2/atest1.do

http://localhost:8080/spingmvc2/test1.do //错误

http://localhost:8080/spingmvc2/hhhtest1.do //错误

*  ： 匹配任意数量的字符

例如：@RequestMapping("/*hello.test")

http://localhost:8080/spingmvc2/test1.do

http://localhost:8080/spingmvc2/wtest1.do

http://localhost:8080/spingmvc2/wwwtest1.do

例如：@RequestMapping("/*/hello.test")

http://localhost:8080/spingmvc2/w/test1.do

http://localhost:8080/spingmvc2/www/test1.do

http://localhost:8080/spingmvc2/test1.do  //错误

http://localhost:8080/spingmvc2/hhhh/www/test1.do  //错误

** ： 匹配多个路径

例如：@RequestMapping("/**/hello.test")

http://localhost:8080/spingmvc2/test1.do

http://localhost:8080/spingmvc2/w/test1.do

http://localhost:8080/spingmvc2/www/test1.do

http://localhost:8080/spingmvc2/hhh/www/test1.do

2. method--限制请求的访问方式【GET、POST.....】

表现形式:@RequestMapping(value = "/login.do",method = RequestMethod.POST )

Index.jsp

<%@page language="java" pageEncoding="UTF-8" %>
<html>
<body>
  <form action="test1.do" method="get">
    <input type="submit" value="测试Method属性"/>
  </form>
</body>
</html>

package com.wangxing.springmvc.controller;
import org.springframework.stereotype.Controller;
import org.springframework.stereotype.Repository;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.servlet.ModelAndView;
@Controller
public class HelloController{
    @RequestMapping(value = "/test1.do",method = RequestMethod.POST)
    public ModelAndView  testRequest(){
        ModelAndView  mav=new ModelAndView();
        mav.addObject("info","hello,网星软件");
        mav.setViewName("test.jsp");
        return  mav;
    }
}

将index.jsp页面中的表单提交放射修改成post即可成功。

只能处理get请求

@RequestMapping(value = "/gethello.do",method = RequestMethod.GET)
@GetMapping(value = "/gethello.do")

只能处理post请求

@RequestMapping(value = "/gethello.do",method = RequestMethod.POST)
@PostMapping(value = "/gethello.do")

4. 请求处理方法接收请求参数值

1. @PathVariable 定义在方法上获取请求url路径上的参数数据

例如:

请求处理方法:

@RequestMapping(value = "/get1/{username}/{password}",method = RequestMethod.GET)
public ModelAndView  getReqParam1(@PathVariable("username")String name,
@PathVariable("password")String pass){
    ModelAndView  mav=new ModelAndView();
    mav.addObject("username",name);
    mav.addObject("password",pass);
    mav.setViewName("test.jsp");
    return  mav;
}

http请求：http://localhost:8080/spingmvc2/get1/zhangsan/123456

注意:web.xml文件的中央中央控制的<url-pattern>/</url-pattern>

2. @RequestParam  定义在方法上，获取请求中通过key=value方式传递的参数数据

例如:

请求处理方法

@RequestMapping(value = "/get2",method = RequestMethod.GET)
public ModelAndView  getReqParam2(@RequestParam("username")String name, @RequestParam("password")String pass){
    ModelAndView  mav=new ModelAndView();
    mav.addObject("username",name);
    mav.addObject("password",pass);
    mav.setViewName("test.jsp");
    return  mav;
}

http请求:http://localhost:8080/spingmvc2/get2?username=lisi&password=000000

web.xml文件的中央中央控制器的<url-pattern>*.do</url-pattern>

请求处理方法:@RequestMapping(value = "/get2.do",method = RequestMethod.GET)
http请求:http://localhost:8080/spingmvc2/get2.do?username=lisi&password=000000

3. HttpServletRequest对象的getParameter()方法接收数据

例如:

请求处理方法

@RequestMapping(value = "/get3.do",method = RequestMethod.GET)
public ModelAndView  getReqParam3(HttpServletRequest  request){
    String name=request.getParameter("username");
    String pass=request.getParameter("password");
    ModelAndView  mav=new ModelAndView();
    mav.addObject("username",name);
    mav.addObject("password",pass);
    mav.setViewName("test.jsp");
    return  mav;
}

http请求:http://localhost:8080/spingmvc2/get3.do?username=wangwu&password=111111

4.在请求处理方法中定义对应参数变量，参数变量的名称与页面元素的name属性值相同

例如:

login.jsp

login.jsp
<%@page language="java" pageEncoding="UTF-8" isELIgnored="false" %>
<html>
<body>
<form action="get4.do" method="post">
    用户名:<input type="text" name="username"/><br>
    密码:<input type="password" name="password"/><br>
    <input type="submit" value="提交"/>
</form>
</body>
</html>

请求处理方法

@RequestMapping(value = "/get4.do",method = RequestMethod.POST)
public ModelAndView  getReqParam4(String username,String password){
    ModelAndView  mav=new ModelAndView();
    mav.addObject("username",username);
    mav.addObject("password",password);
    mav.setViewName("test.jsp");
    return  mav;
}

5. 将需要提交的请求参数值封装到java对象中【java对象的成员变量的名称一定要与页面元素的name属性值相同】

例如:

register.jsp

<%@page language="java" pageEncoding="UTF-8" isELIgnored="false" %>
<html>
<body>
<form action="get5.do" method="post">
    用户名:<input type="text" name="username"/><br>
    密码:<input type="password" name="password"/><br>
    年龄:<input type="text" name="age"/><br>
    地址:<input type="text" name="address"/><br>
    日期:<input type="text" name="day"/><br>
    <input type="submit" value="提交"/>
</form>
</body>
</html>

PersonBean.java

PersonBean.java
package com.wangxing.springmvc.bean;
import org.springframework.format.annotation.DateTimeFormat;
import java.util.Date;
public class PersonBean {
    private  String username;
    private  String password;
    private  Integer age;
    private  String address;
    @DateTimeFormat(pattern="yyyy-MM-dd")
    private Date day;
    public String getUsername() {
        return username;
    }
    public void setUsername(String username) {
        this.username = username;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    public Integer getAge() {
        return age;
    }
    public void setAge(Integer age) {
        this.age = age;
    }
    public String getAddress() {
        return address;
    }
    public void setAddress(String address) {
        this.address = address;
    }
    public Date getDay() {
        return day;
    }
    public void setDay(Date day) {
        this.day = day;
    }
}

请求处理方法：

@RequestMapping(value = "/get5.do",method = RequestMethod.POST)
public ModelAndView  getReqParam5(PersonBean personBean){
    ModelAndView  mav=new ModelAndView();
    mav.addObject("personBean",personBean);
    mav.setViewName("test.jsp");
    return  mav;
}

注意:java对象的成员变量的名称一定要与页面元素的name属性值相同

6. 将被提交的请求参数组织成json数据【后面介绍】

SpringMVC访问静态资源

当我们使用SPringMVC访问HTML文件的时候出现404错误，因为SpringMVC不支持静态资源的访问【.html /  .js  / .css  /.jpg.....】

方案一：激活Tomcat的defaultServlet来处理静态文件[web.xml]

<servlet-mapping>
    <servlet-name>default</servlet-name>
    <url-pattern>*.jpg</url-pattern>
</servlet-mapping>
<servlet-mapping>
    <servlet-name>default</servlet-name>
    <url-pattern>*.js</url-pattern>
</servlet-mapping>
<servlet-mapping>
    <servlet-name>default</servlet-name>
    <url-pattern>*.css</url-pattern>
</servlet-mapping>

要写在DispatcherServlet的前面， 让defaultServlet先拦截，这个就不会进入Spring了，我想性能是最好的吧。

方案二： 在spring3.0.4以后版本提供了mvc:resources

<!--对静态资源文件的访问-->

<mvc:resources mapping="/images/**" location="/images/" />

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

<mvc:resources mapping="/css/**" location="/css/" />

SpringMVC

SpringMVC的请求处理方法接收请求参数

请求处理方法接收json参数

1创建项目

2完善项目

3导入依赖

<!-- 配置开发SpringMVC所以来的jar包 -->
<!-- https://mvnrepository.com/artifact/org.springframework/spring-webmvc -->
<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-webmvc</artifactId>
  <version>5.1.5.RELEASE</version>
</dependency>
<!-- 配置ServletAPI依赖 -->
<!-- https://mvnrepository.com/artifact/javax.servlet/javax.servlet-api -->
<dependency>
  <groupId>javax.servlet</groupId>
  <artifactId>javax.servlet-api</artifactId>
  <version>3.0.1</version>
  <scope>provided</scope>
</dependency>
<!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-core -->
<dependency>
  <groupId>com.fasterxml.jackson.core</groupId>
  <artifactId>jackson-core</artifactId>
  <version>2.9.8</version>
</dependency>
<!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-databind -->
<dependency>
  <groupId>com.fasterxml.jackson.core</groupId>
  <artifactId>jackson-databind</artifactId>
  <version>2.9.8</version>
</dependency>
<!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-annotations -->
<dependency>
  <groupId>com.fasterxml.jackson.core</groupId>
  <artifactId>jackson-annotations</artifactId>
  <version>2.9.8</version>
</dependency>

4配置web.xml

<!DOCTYPE web-app PUBLIC
 "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
 "http://java.sun.com/dtd/web-app_2_3.dtd" >
<web-app>
  <display-name>Archetype Created Web Application</display-name>
  <servlet>
    <servlet-name>dispatcherServle</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <init-param>
      <param-name>contextConfigLocation</param-name>
      <param-value>classpath:springmvc.xml</param-value>
    </init-param>
  </servlet>
  <servlet-mapping>
    <servlet-name>dispatcherServle</servlet-name>
    <url-pattern>*.do</url-pattern>
  </servlet-mapping>
</web-app>

5配置SpringMVC配置文件

<?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:mvc="http://www.springframework.org/schema/mvc"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans.xsd
       http://www.springframework.org/schema/mvc
       http://www.springframework.org/schema/mvc/spring-mvc.xsd
        http://www.springframework.org/schema/context
       http://www.springframework.org/schema/context/spring-context.xsd">
    <!--开启注解-->
    <mvc:annotation-driven></mvc:annotation-driven>
    <!--配置自动扫描包-->
    <context:component-scan base-package="com.wangxing.springmvc.controller"></context:component-scan>
</beans>

6创建HTML页面

<!DOCTYPE html>
<html lang="en">
	<head>
    <meta charset="UTF-8">
    <title>用户注册</title>
   </head>
<body>
    <table>
        <tr>
            <td colspan="2"><h1>用户注册</h1></td>
        </tr>
        <tr>
            <td>用户名:</td>
            <td><input id="username" type="text" name="username"/></td>
        </tr>
        <tr>
            <td>密码:</td>
            <td><input id="password" type="password" name="password"/></td>
        </tr>
        <tr>
            <td>年龄:</td>
            <td><input id="myage" type="text" name="myage"/></td>
        </tr>
        <tr>
            <td>地址:</td>
            <td><input id="myaddress" type="text" name="myaddress"/></td>
        </tr>
        <tr>
            <td colspan="2"><input id="but1" type="button" value="提交" /></td>
        </tr>
    </table>
</body>
</html>

7.在webapp文件夹中创建jquery文件，并将jquery-3.5.1.min.js复制进jquery文件。

   重新加载一次jquery文件中的jquery-3.5.1.min.js文件

8 在html文件中导入jquery，并发送ajax请求

<script  src="jquery/jquery-3.5.1.min.js"></script>
<script>
    $(function () {
        $("#but1").click(function () {
            var username=$("#username").val();
            var password=$("#password").val();
            var myage=$("#myage").val();
            var myaddress=$("#myaddress").val();
            //组织成json数据[json对象]
            var params={"username":username,"password":password,"myage":myage,"myaddress":myaddress};
            //3.将上面组织好的json数据发送到控制器类的请求处理方法中接收处理
            $.ajax({
                //设置访问地址
                url:"http://localhost:8080/springmvc3/test1.do",
                //设置被发送的具体数据【json字符串】
                data:JSON.stringify(params),
                //设置请求提交方式
                type:"POST",
                //设置响应数据的类型是json
                datatype:"json",
                //设置请求的数据是json数据，绝对不可以省略
                contentType:"application/json",
                //设置请求发送成功以后的处理函数
                success:function(data){
                  alert(data);
                }
            });
        });
    });
</script>

注意:不能使用jquery的post方式发送ajax请求，因为jquery的post方式发送ajax请求时http协议的请求头中的contentType的属性值不是"application/json"，所以会出现“Failed to load resource: the server responded with a status of 415 (Unsupported Media Type)”错误。

9 创建被提交的json数据对应的java实体类

注意:java实体类的成员变量名称与被提交的json数据中的key值相同。

10创建控制器

package com.wangxing.springmvc.controller;
import com.wangxing.springmvc.bean.UserBean;
import org.springframework.stereotype.Controller;
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;
@Controller
public class HelloController {
    @RequestMapping(value = "/test1.do",method = RequestMethod.POST)
    public void   testRequest(@RequestBody UserBean userBean){
        System.out.println("username=="+userBean.getUsername());
        System.out.println("password=="+userBean.getPassword());
        System.out.println("myage=="+userBean.getMyage());
        System.out.println("myaddress=="+userBean.getMyaddress());
    }
}

11.测试

http://localhost:8080/springmvc3/register.html

控制台输出

@RequestBody

@RequestBody注解接收来自请求体中的参数。

一般用于处理非 Content-Type: application/x-www-form-urlencoded编码格式的数据，比如：application/json、application/xml等类型的数据。

“Content-Type：application/json”使用注解@RequestBody可以将请求体里面所有的json数据传到后端，后端再进行解析，封装成java对象。

请求处理方法向浏览器页面返回json数据

package com.wangxing.springmvc.controller;
import com.wangxing.springmvc.bean.UserBean;
import org.springframework.stereotype.Controller;
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;
@Controller
public class HelloController {
    @RequestMapping(value = "/test1.do")
    @ResponseBody
    public UserBean   testRequest(){
        UserBean user1=new UserBean();
        user1.setUsername("zhangsan");
    	user1.setPassword("000000");
    	user1.setMyage(23);
    	user1.setMyaddress("西安");
        return user1;
    }
@RequestMapping(value = "/test2.do")
@ResponseBody
public List<UserBean> testRequest2(){
    UserBean user1=new UserBean();
    user1.setUsername("zhangsan");
    user1.setPassword("000000");
    user1.setMyage(23);
    user1.setMyaddress("西安");
    UserBean user2=new UserBean();
    user2.setUsername("lisi");
    user2.setPassword("111111");
    user2.setMyage(24);
    user2.setMyaddress("北京");
    List<UserBean>  userBeanList=new ArrayList<UserBean>();
    userBeanList.add(user1);
    userBeanList.add(user2);
    return userBeanList;
	}
}

http://localhost:8080/springmvc3/test1.do

{"username":"zhangsan","password":"000000","myage":23,"myaddress":"西安"}

http://localhost:8080/springmvc3/test2.do

[{"username":"zhangsan","password":"000000","myage":23,"myaddress":"西安"},{"username":"lisi","password":"111111","myage":24,"myaddress":"北京"}]

@ResponseBody的作用其实是将java对象转为json格式的数据【json对象】。

Json对象与json字符串之间的转换

Json对象---》json字符串   JSON.stringify(json对象)

json字符串---》Json对象   eval("("+json字符串+")");

例如:

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>用户注册</title>
    <script  src="jquery/jquery-3.5.1.min.js"></script>
    <script>
        $(function () {
            $("#but1").click(function () {
                //定义json对象
                var  jsonObj={id:1001,username:"zhangsan",age:23,address:"西安"};
                //alert(jsonObj); //[object Object]
                var jsonString=JSON.stringify(jsonObj);
                alert(jsonString); //{"id":1001,"username":"zhangsan","age":23,"address":"西安"}
            });
            $("#but2").click(function () {
                   //var jsonString="{\"id\":1001,\"username\":\"zhangsan\",\"age\":23,\"address\":\"西安\"}";
                   var jsonString="{'id':1001,'username':'zhangsan','age':23,'address':'西安'}";
                   var jsonObj=eval("("+jsonString+")");
                   alert(jsonObj);  //[object Object]
            });
        });
    </script>
</head>
<body>
    <input id="but1" type="button" value="json对象转换成Json字符串" /><br>
    <input id="but2" type="button" value="Json字符串转换成json对象" />
</body>
</html>