SpringMVC(2)

0.总体结构

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>gy.com</groupId>
    <artifactId>springmvc</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>war</packaging>
    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>6</source>
                    <target>6</target>
                </configuration>
            </plugin>
        </plugins>
    </build>


    <dependencies>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>5.2.10.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>servlet-api</artifactId>
            <version>3.0-alpha-1</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.11.3</version>
        </dependency>
        <dependency>
            <groupId>commons-fileupload</groupId>
            <artifactId>commons-fileupload</artifactId>
            <version>1.4</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.18</version>
        </dependency>
    </dependencies>
</project>

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">
<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:application.xml</param-value>
</init-param>
</servlet>
    <servlet-mapping>
        <servlet-name>dispatcherServlet</servlet-name>
        <!--除了web资源根路径下的jsp文件，其余所有都经过dispatcherServlet-->
        <url-pattern>/</url-pattern>
    </servlet-mapping>

</web-app>

application.xml
把自定义的转换器组件String2DateConverter（id=conversionService2）放入到converters

<?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:aop="http://www.springframework.org/schema/aop"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       xsi:schemaLocation="
        http://www.springframework.org/schema/beans https://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
        http://www.springframework.org/schema/aop https://www.springframework.org/schema/aop/spring-aop.xsd">

    <context:component-scan base-package="com.parameter"/>
    <mvc:annotation-driven conversion-service="conversionService2"/>

    <bean id="conversionService2" class="org.springframework.format.support.FormattingConversionServiceFactoryBean">
        <property name="converters">
            <set>
                <ref bean="string2DateConverter"/>
                <!--<bean class="com.cskaoyan.converter.String2DateConverter"/>-->

            </set>
        </property>
    </bean>

    <!--组件id为固定值，不可以修改为其他值-->
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
    <property name="maxUploadSize" value="500000"/>
</bean>

</beans>

1.SpringMVC案例一

1.1 Handler方法的形参

主要讲请求参数的封装

springMvc提供的转换器让我们能够直接以需要的类型来接收请求参数

1.1.1 直接封装（请求参数名和handler方法的形参名一致）

1.1.1. 主要是基本类型和对应的包装类

localhost:8080/register?username=xxxx&password=zzzzz&age=36

1.1.2 Date

（1）使用springmvc提供的日期转换器@DateTimeFormat(pattern)
（2）自定义转换器String2DateConverter（String 👉 Date）
implements Converter<S,T>

BaseRespVo

@Data
public class BaseRespVo<T> {

    T data;
    String message;
    long errno;

    public static BaseRespVo ok(){
        BaseRespVo baseRespVo = new BaseRespVo();
        baseRespVo.setMessage("成功");
        baseRespVo.setErrno(0);
        return baseRespVo;
    }
    public static  BaseRespVo ok(Object data){
        BaseRespVo ok = BaseRespVo.ok();
        ok.setData(data);
        return ok;
    }
}

String2DateConverter（转换器）

@Component
public class String2DateConverter implements Converter<String, Date> {
    //请求参数名和handler方法的形参名一致，类型又匹配为Converter接口这里的类型
    @Override
    @SneakyThrows
    public Date convert(String s) {
        Date date=null;
        String pattern1 = "yyyy-MM-dd";
        String pattern2 = "yyyy-MM-dd HH:mm:ss";
        String pattern3 = "yyyy-MM-dd HH:mm";
        if (s.length() == pattern1.length()){
            try {
                date = new SimpleDateFormat(pattern1).parse(s);
            } catch (ParseException e) {
                e.printStackTrace();
            }
        }else if (s.length() == pattern2.length()){
            try {
                date = new SimpleDateFormat(pattern2).parse(s);
            } catch (ParseException e) {
                e.printStackTrace();
            }
        } else if (s.length() == pattern3.length()) {
            try {
                date = new SimpleDateFormat(pattern3).parse(s);
            } catch (ParseException e) {
                e.printStackTrace();
            }
        }
        return date;

    }
}

ParameterController

//请求参数的封装
@RestController
public class ParameterController {
    //localhost:8080/register?username=ffffff&password=uuuu&age=36
    //👉 建议：若想接收基本类型，不建议直接写基本类型，
    // 建议以基本类型所对应的包装类来接收
    @RequestMapping("register")
    public BaseRespVo register(String username, String password, Integer age, Boolean married) {
        return BaseRespVo.ok(username + ":" + password + ":" + age);
    }

    //localhost:8080/register2?username=jingtian&password=niupi&age=36&birthday=2000-05-15
    //如果想要接收Date需要指定日期的格式
    @RequestMapping("register2")
    public BaseRespVo register2(String username, String password, Integer age,  @DateTimeFormat(pattern = "yyyy-MM-dd") Date birthday) {
        System.out.println(birthday);
        return BaseRespVo.ok();
    }

    @Autowired
    ConfigurableConversionService conversionService;

    //localhost:8080/register3?username=jingtian&password=niupi&age=36&birthday=2000-05-15
    //localhost:8080/register3?username=jingtian&password=niupi&age=36&birthday=2000-05-15 15:24
    //localhost:8080/register3?username=jingtian&password=niupi&age=36&birthday=2000-05-15 15:24:28
    @RequestMapping("register3")
    public BaseRespVo register3(String username, String password, Integer age,Date birthday) {
        System.out.println(birthday);
        return BaseRespVo.ok();
    }
    }

结果：

1.2 文件类型（文件的接收、上传）

1.2.1 依赖

commons-io/commons-fileupload

1.2.2 组件注册

multipartResolver

1.2.3 构造form表单

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
<h1>文件上传</h1>
<form action="/file/upload" enctype="multipart/form-data" method="post">
    <%--name属性会体现为请求参数名--%>
    <input type="file" name="myfile">
        <input type="submit">
</form>
<hr>
<h1>多个文件上传</h1>
<form action="/files/upload" enctype="multipart/form-data" method="post">
    <%--name属性会体现为请求参数名--%>
    <input type="file" multiple name="myfiles">
        <input type="submit">
</form>
</body>
</html>

1.2.4 handler方法接收文件

• String[] hobbys
  localhost/register4?hobyys=sing&hobbys=dance&hobbys=basketball
  多个请求参数名相同，就意味着可以使用数组来接收

• 文件也可以以数组的形式来接收
  

• 多文件上传页面属性

• 

@RestController
public class ParameterController {
  
//请求参数名和handler方法的形参名（MultiparFile）一致
        @RequestMapping("file/upload")
        public BaseRespVo fileUpload(MultipartFile myfile){
            String name = myfile.getName();//请求参数名 👉 myfile
            String originalFilename = myfile.getOriginalFilename(); //上传时选择的文件名
            String contentType = myfile.getContentType(); //文件类型
            long size = myfile.getSize();

            //save
            File path = new File("D:\\gy\\spring");
            //构造一个file来接收multipartFile
            File file = new File(path, originalFilename);//想要以什么文件名保存，第二个参数就写什么

            try {
                //将multipartFile转换为file
                myfile.transferTo(file);
            } catch (IOException e) {
                e.printStackTrace();
            }
            return BaseRespVo.ok();
        }

    //localhost:8080/register4?hobyys=sing&hobbys=dance&hobbys=basketball&username=jingtian&age=25
    //数组数据
    @RequestMapping("register4")
    public BaseRespVo register4(String username,Integer age,String[] hobbys){
        return BaseRespVo.ok(hobbys);
    }

    //请求参数名和handler方法的形参名(MultipartFile)一致
    @RequestMapping("files/upload")
    public BaseRespVo filesUpload(MultipartFile[] myfiles) {
        for (MultipartFile myfile : myfiles) {
            String name = myfile.getName();//请求参数名 👉 myfile
            String originalFilename = myfile.getOriginalFilename();//上传时选择的文件名
            String contentType = myfile.getContentType();//文件类型
            long size = myfile.getSize();

            //save
            File path = new File("D:\\gy\\spring");
            //构造一个file来接收multipartFile
            File file = new File(path, originalFilename);//你想要以什么文件名保存，第二个参数就写什么

            try {
                myfile.transferTo(file);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return BaseRespVo.ok();

    }
}

结果：

1.3使用pojo封装

handler形参变更为pojo类中的成员变量 👉 请求参数名和javabean的成员变量名（set）一致

Order

@Data
@AllArgsConstructor
@NoArgsConstructor
@Accessors(chain = true)
public class Order {

    String name;
    Double price;
}

UserDetail

@Data
@Accessors(chain = true)
@NoArgsConstructor
@AllArgsConstructor
public class UserDetail {

    String mobile;
    String email;
}

User

@Data
@AllArgsConstructor//有参构造
@NoArgsConstructor//无参构造
@Accessors(chain = true)//可以连续调用
public class User {

    String username;
    String password;
    Integer age;

    //@DateTimeFormat //请求参数封装过程中的转换
    @JsonFormat(pattern = "yyyy-MM-dd HH:mm:ss", timezone = "GMT+8")//响应结果json格式的限定
    Date birthday;
    //localhost:8080/javabean/register?username=jingtian&userDetail.mobile=100&userDetail.email=cskaoyan@qq.com
    UserDetail userDetail;

    //localhost:8080/javabean/register?username=jingtian&
    // orders[0].name=lanqiu&orders[0].price=50&
    // orders[1].name=tiaowuji&orders[1].price=5000

    //[]需要使用到uri编码
    // [ 👉 %5B
    // ] 👉 %5D
    //http://localhost:8080/javabean/register?username=jingtian&orders%5B0%5D.name=lanqiu&orders%5B0%5D.price=50&orders%5B1%5D.name=tiaowuji&orders%5B1%5D.price=5000&birthday=2021-04-02
    List<Order> orders;
}

//localhost:8080/javabean/register?username=jingtian&orders[0].name=lanqiu&orders[0].price=50&
// orders[1].name=tiaowuji&orders[1].price=5000不能访问

[]需要使用到uri编码
[ 👉 %5B
] 👉 %5D
以下为转换网站：
http://tool.chinaz.com/tools/urlencode.aspx

手动转换后：
http://localhost:8080/javabean/register?username=jingtian&orders%5B0%5D.name=lanqiu&orders%5B0%5D.price=50&orders%5B1%5D.name=tiaowuji&orders%5B1%5D.price=5000&birthday=2021-04-02
访问成功：

1.4 json请求参数

请求方法：post
Content-Type：application/json
data: json字符串

JsonController

@RestController
public class JsonController {
    
    @RequestMapping("json/login")
    public BaseRespVo login(@RequestBody User user){
        return BaseRespVo.ok(user);
    }
}

{“username”:“jingtian”,“password”:35777,“age”:66,“birthday”:“2021-04-02 00:00:00”,“userDetail”:{“mobile”:“4444”,“email”:“67657”},“orders”:[{“name”:“lanqiu”,“price”:50.0},{“name”:“tiaowuji”,“price”:5000.0}]}

json格式化校验：
https://www.bejson.com/json/format/

或者下载插件：GsonFormat

快捷键：Alt+s

JsonBean

public class JsonBean {


    /**
     * username : jingtian
     * password : 35777
     * age : 66
     * birthday : 2021-04-02 00:00:00
     * userDetail : {"mobile":"4444","email":"67657"}
     * orders : [{"name":"lanqiu","price":50},{"name":"tiaowuji","price":5000}]
     */

    private String username;
    private int password;
    private int age;
    private String birthday;
    private UserDetailBean userDetail;
    private List<OrdersBean> orders;

    public String getUsername() {
        return username;
    }

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

    public int getPassword() {
        return password;
    }

    public void setPassword(int password) {
        this.password = password;
    }

    public int getAge() {
        return age;
    }

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

    public String getBirthday() {
        return birthday;
    }

    public void setBirthday(String birthday) {
        this.birthday = birthday;
    }

    public UserDetailBean getUserDetail() {
        return userDetail;
    }

    public void setUserDetail(UserDetailBean userDetail) {
        this.userDetail = userDetail;
    }

    public List<OrdersBean> getOrders() {
        return orders;
    }

    public void setOrders(List<OrdersBean> orders) {
        this.orders = orders;
    }

    public static class UserDetailBean {
        /**
         * mobile : 4444
         * email : 67657
         */

        private String mobile;
        private String email;

        public String getMobile() {
            return mobile;
        }

        public void setMobile(String mobile) {
            this.mobile = mobile;
        }

        public String getEmail() {
            return email;
        }

        public void setEmail(String email) {
            this.email = email;
        }
    }

    public static class OrdersBean {
        /**
         * name : lanqiu
         * price : 50
         */

        private String name;
        private int price;

        public String getName() {
            return name;
        }

        public void setName(String name) {
            this.name = name;
        }

        public int getPrice() {
            return price;
        }

        public void setPrice(int price) {
            this.price = price;
        }
    }
}

1.5 Model

1.5.1

• 返回值为String作为viewname时，使用Model作为形参
• 由于cookie不能直接写在形参中，要通过request来获得
  
  CookieSessionController

@RestController
public class CookieSessionController {

    @RequestMapping("fetch/cookie")
    public BaseRespVo fetchCookie(HttpServletRequest request){
        Cookie[] cookies = request.getCookies();
        for (Cookie cookie : cookies) {
            System.out.println(cookie.getName() + " = " + cookie.getValue());
        }
        return BaseRespVo.ok();
    }

    @RequestMapping("put/session")
    public BaseRespVo putSession(String username, HttpSession session){
        session.setAttribute("username",username);
        return BaseRespVo.ok();
    }
    @RequestMapping("fetch/session")
    public BaseRespVo fetchSession(HttpSession session) {
        Object username = session.getAttribute("username");
        return BaseRespVo.ok(username);
    }
    @RequestMapping("fetch/session2")
    public BaseRespVo fetchSession2(HttpServletRequest request) {
        HttpSession session = request.getSession();
        return BaseRespVo.ok();
    }

}

再次发送后

或者使用postman

1.5.2 Session

可以直接在形参中获得