重温spring项目第六天

分页

导入pom

<!-- https://mvnrepository.com/artifact/com.github.pagehelper/pagehelper -->
<dependency>
    <groupId>com.github.pagehelper</groupId>
    <artifactId>pagehelper</artifactId>
    <version>5.1.10</version>
</dependency>

mybatis-config.xml

<plugins>
    <!-- com.github.pagehelper为PageHelper类所在包名 -->
    <plugin interceptor="com.github.pagehelper.PageInterceptor">
        <!-- 选择mysql数据库的分页方式 -->
        <property name="helperDialect" value="mysql"/>
        <property name="rowBoundsWithCount" value="true"/>
    </plugin>
</plugins>

使用方法：

@Test
public void limitTest(){
    SqlSession session = MyBatisMapperUtils.getSession();
    UserMapper mapper = session.getMapper(UserMapper.class);

    //1. 开启分页 : pageNum 第几页，从1开始， pageSize 每页显示条数
    PageHelper.startPage(1,3);

    //2. 条件查询
    List<User> users = mapper.selectAll();

    //3. 将查询结果交给PageInfo处理
    PageInfo<User> pageInfo = new PageInfo<>(users);
    
    //分页相关结果
    long total = pageInfo.getTotal();       //总条数
    int pageNum = pageInfo.getPageNum();    //当前页
    int pages = pageInfo.getPages();        //总页数
    List<User> pageInfoList = pageInfo.getList();   //当前页数据

    System.out.println("总条数:"+total+" 当前页:"+pageNum+" 总页数"+pages);
    System.out.println("当前页数据....");
    for (User user : pageInfoList) {
        System.out.println(user);
    }

    MyBatisMapperUtils.closeSession();
}

SQL分页：limit {startIndex} {pageSize}

• startIndex：查询结果的开始索引 = （当前页数 -1）* 每页显示条数
• pageSize：每页显示条数

springMVC

spring是框架，baimvc是一种设计模式。，M代表model；duV代表View；C代表controller从字面意思你也可以看出来M是指模型一般dao指DAO和service ；view代表显示一般指页面eg：jsp、html 等，c指的是控制器

一些配置

pom

<properties>
   <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
   <maven.compiler.source>1.8</maven.compiler.source>
   <maven.compiler.target>1.8</maven.compiler.target>
   <spring.version>4.2.4.RELEASE</spring.version>
 </properties>

 <dependencies>

   <!-- spring start -->

   <!--spring core start-->
   <dependency>
     <groupId>org.springframework</groupId>
     <artifactId>spring-beans</artifactId>
     <version>${spring.version}</version>
   </dependency>
   <dependency>
     <groupId>org.springframework</groupId>
     <artifactId>spring-core</artifactId>
     <version>${spring.version}</version>
   </dependency>
   <dependency>
     <groupId>org.springframework</groupId>
     <artifactId>spring-context</artifactId>
     <version>${spring.version}</version>
   </dependency>
   <dependency>
     <groupId>org.springframework</groupId>
     <artifactId>spring-expression</artifactId>
     <version>${spring.version}</version>
   </dependency>
   <dependency>
     <groupId>org.springframework</groupId>
     <artifactId>spring-context-support</artifactId>
     <version>${spring.version}</version>
   </dependency>
   <!--spring core end-->

   <!--spring aop start-->
   <dependency>
     <groupId>org.springframework</groupId>
     <artifactId>spring-aop</artifactId>
     <version>${spring.version}</version>
   </dependency>
   <!--spirng aop end-->

   <!--spring aspects start-->
   <dependency>
     <groupId>org.springframework</groupId>
     <artifactId>spring-aspects</artifactId>
     <version>${spring.version}</version>
   </dependency>
   <!--spring aspects end-->

   <!--spring instrumentation start -->
   <dependency>
     <groupId>org.springframework</groupId>
     <artifactId>spring-instrument</artifactId>
     <version>${spring.version}</version>
   </dependency>
   <!--spring instrumentation end-->

   <!--spring messaging start -->
   <dependency>
     <groupId>org.springframework</groupId>
     <artifactId>spring-messaging</artifactId>
     <version>${spring.version}</version>
   </dependency>
   <!--spring messaging end-->

   <!--spring data access start -->
   <dependency>
     <groupId>org.springframework</groupId>
     <artifactId>spring-jdbc</artifactId>
     <version>${spring.version}</version>
   </dependency>
   <dependency>
     <groupId>org.springframework</groupId>
     <artifactId>spring-orm</artifactId>
     <version>${spring.version}</version>
   </dependency>
   <dependency>
     <groupId>org.springframework</groupId>
     <artifactId>spring-oxm</artifactId>
     <version>${spring.version}</version>
   </dependency>
   <dependency>
     <groupId>org.springframework</groupId>
     <artifactId>spring-jms</artifactId>
     <version>${spring.version}</version>
   </dependency>
   <dependency>
     <groupId>org.springframework</groupId>
     <artifactId>spring-tx</artifactId>
     <version>${spring.version}</version>
   </dependency>
   <!--spring data access end-->

   <!--spring web start -->
   <dependency>
     <groupId>org.springframework</groupId>
     <artifactId>spring-websocket</artifactId>
     <version>${spring.version}</version>
   </dependency>
   <dependency>
     <groupId>org.springframework</groupId>
     <artifactId>spring-web</artifactId>
     <version>${spring.version}</version>
   </dependency>


   <dependency>
     <groupId>org.springframework</groupId>
     <artifactId>spring-webmvc-portlet</artifactId>
     <version>${spring.version}</version>
   </dependency>

   <dependency>
     <groupId>org.springframework</groupId>
     <artifactId>spring-webmvc</artifactId>
     <version>${spring.version}</version>
   </dependency>
   <!--spring web end -->

   <!--spring test start -->
   <dependency>
     <groupId>org.springframework</groupId>
     <artifactId>spring-test</artifactId>
     <version>${spring.version}</version>
   </dependency>

   <!--spring test end -->
   <!-- spring end -->


   <dependency>
     <groupId>junit</groupId>
     <artifactId>junit</artifactId>
     <version>4.12</version>
     <scope>test</scope>
   </dependency>
   <dependency>
     <groupId>tk.mybatis</groupId>
     <artifactId>mapper</artifactId>
     <version>3.5.2</version>
   </dependency>
   <dependency>
     <groupId>com.github.pagehelper</groupId>
     <artifactId>pagehelper</artifactId>
     <version>3.7.5</version>
   </dependency>
   <dependency>
     <groupId>org.mybatis</groupId>
     <artifactId>mybatis</artifactId>
     <version>3.4.5</version>
   </dependency>

   <dependency>
     <groupId>mysql</groupId>
     <artifactId>mysql-connector-java</artifactId>
     <version>5.1.47</version>
   </dependency>
   <dependency>
     <groupId>org.mybatis</groupId>
     <artifactId>mybatis-spring</artifactId>
     <version>1.3.2</version>
   </dependency>
   <dependency>
     <groupId>com.alibaba</groupId>
     <artifactId>druid</artifactId>
     <version>1.1.10</version>
   </dependency>
   <dependency>
     <groupId>junit</groupId>
     <artifactId>junit</artifactId>
     <version>4.12</version>
     <scope>compile</scope>
   </dependency>
 </dependencies>

resource/springmvc.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:p="http://www.springframework.org/schema/p"
       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-4.2.xsd
                  http://www.springframework.org/schema/mvc
                  http://www.springframework.org/schema/mvc/spring-mvc-4.2.xsd
                  http://www.springframework.org/schema/context
                  http://www.springframework.org/schema/context/spring-context-4.2.xsd">

    <!-- 扫描注解包 -->
    <context:component-scan base-package="com.ls.controller" />
</beans>

WEB-INF/web.xml

<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">

  <display-name>Archetype Created Web Application</display-name>


  <!-- 设置核心配置器 -->
  <servlet>
    <servlet-name>springmvc</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>springmvc</servlet-name>
    <url-pattern>*.do</url-pattern>
  </servlet-mapping>

</web-app>

创建项目

注意要选对了东西！！！！

项目刚开始的时候只给了你个pom文件，里面的东西大部分不能要，删除掉name标签下面的所有标签，然后导入我上面的pom

创建包名，项目资源目录，如下：

写代码的（java）弄成纯蓝色的，写配置的（resources）资源目录 弄成三道杠的

resouces下创建 springmvc.xml 更改为上面的配置

WEB-INF下的web.xml 更改为上面的配置

项目该有的样子：

入门程序

package com.ls.controller;

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

@Controller
public class HelloWorld {


    @RequestMapping("/show")
    public String show(){
        System.out.println("你好   死狗");
        return "WEB-INF/hello.jsp";
    }
}

@Controller 标注在类上，表示当前类交给Spring容器管理，对象的创建和销毁由容器负责，默认以单例模式管理

@RequestMapping(“/show”) 类或者方法上 描述URL的请求路径

return “WEB-INF/hello.jsp”; 默认是servlet跳转，都知道web-inf下文件无法访问，但是站内跳转则可以访问

准备访问的文件

hello.jsp

<%--
  Created by IntelliJ IDEA.
  User: qidai
  Date: 2020/7/27
  Time: 14:00
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>社会青年</title>
</head>
<body>

我看我几分 像从前
</body>
</html>

然后配置tomcat，这个每个人的ide不一样位置不同

之后就可以开启tomcat了

如果你觉得return那个默认为页面跳转的内容要多写很多英文，很麻烦，又很容易手误出错，可以在 springmvc.xml 配置视图解析器：

<!--spring容器的包扫描-->
<context:component-scan base-package="com.czxy.mvc.controller"/>

<!--视图解析器-->
<bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
    <property name="prefix" value="/WEB-INF/pages/"/>
    <property name="suffix" value=".jsp"/>
    <property name="contentType" value="text/html;charset=UTF-8"/>
</bean>

prefix是前缀的意思，会作为前缀拼接你的return

suffix是后缀的意思，会作为后缀拼接你的return

接收参数

普通参数

• 请求路径

http://localhost:8080/user/select/id/username.do?id=1001&username=tomcat

• controller

@RequestMapping("/select/id/username")
public String testParam(Integer id,String username){
    System.out.println("id="+id+" username="+username);
    return "success";
}

用 ？ 作为参数传递的开始，然后拼接参数 以及数值，参数自动映射，只要key值一样

pojo类接收

User.java

public class User {
    private Integer id;
    private String name;
    private Float money;
    private Address address;
    //get set toString...
}

Address.java

public class Address {
    private String provinceName;
    private String cityName;
    //get set toString...
}

添加表单页面

user.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
    <form action="/user/collection.do" method="post">
        用户名称：<input type="text" name="name" ><br/>
        用户余额：<input type="text" name="money" ><br/>
        用户地址-省：<input type="text" name="address.provinceName" ><br/>
        用户地址-市：<input type="text" name="address.Name" ><br/>
                    <input type="submit" value="保存">
    </form>
</body>
</html>

controller接收参数

@RequestMapping("/collection.do")
public String saveAccount(User user){
    System.out.println(user);
    return "success";
}

可以将参数自动封装到实体类中的实体类，格式是：另一个实体类在这个实体类中的成员名字.另一个实体类自己的属性 用上面的例子来说就是：address.cityName

pojo类中各种类型的集合，数组

添加pojo类

public class Bank {
    private String account;
    private Double money;
    //get set
}

修改User类

public class User {
    private Integer id;
    private String name;
    private Float money;
    private Address address;

    //集合类型属性
    private List<Integer> ids;
    private List<Bank> bankList;
    private Map<String,Integer> sizeMap;
    private Map<String,Bank> bankMap;

    //get set
}

collection.jsp

<form action="/user/collection.do" method="post">
    用户名称：<input type="text" name="name" ><br/>
    用户余额：<input type="text" name="money" ><br/>
    用户地址-省：<input type="text" name="address.provinceName" ><br/>
    用户地址-市：<input type="text" name="address.Name" ><br/>

    IdsItegerList:<input type="text" name="ids[0]" ><br/>
    IdsItegerList:<input type="text" name="ids[1]" ><br/>
    IdsItegerList:<input type="text" name="ids[2]" ><br/>

    String[]:<input type="text" name="props" ><br/>
    String[]:<input type="text" name="props" ><br/>
    
    bankList[0].account：<input type="text" name="bankList[0].account" ><br/>
    bankList[0].money：<input type="text" name="bankList[0].money" ><br/>
    bankList[1].account：<input type="text" name="bankList[1].account" ><br/>
    bankList[1].money：<input type="text" name="bankList[1].money" ><br/>

    sizeMap-S：<input type="text" name="sizeMap['S']" ><br/>
    sizeMap-M：<input type="text" name="sizeMap['M']"><br/>
    sizeMap-L：<input type="text" name="sizeMap['L']"><br/>

    bankMap-bank1-account: <input type="text" name="bankMap['bank1'].account"><br/>
    bankMap-bank1-money: <input type="text" name="bankMap['bank1'].money"><br/>
    bankMap-bank2-account: <input type="text" name="bankMap['bank2'].account"><br/>
    bankMap-bank2-money: <input type="text" name="bankMap['bank2'].money"><br/>
    <input type="submit" value="保存">
</form>

controller

@RequestMapping("/collection.do")
public String collection(User user,String[] props){
    System.out.println(user);
    return "success";
}

上面已经演示出了所有通过form表单传参的情况了，相信你有了看懂实体类的实力之后，这个也是不在话下了

传参乱码

在你的前端控制器中添加下面的代码（web.xml）

<!-- 配置 springMVC编码过滤器 -->
<filter>
    <filter-name>CharacterEncodingFilter</filter-name>
    <filter-class>
        org.springframework.web.filter.CharacterEncodingFilter
    </filter-class>
    <!-- 设置过滤器中的属性值 -->
    <init-param>
        <param-name>encoding</param-name>
        <param-value>UTF-8</param-value>
    </init-param>
    <!-- 启动过滤器 -->
    <init-param>
        <param-name>forceEncoding</param-name>
        <param-value>true</param-value>
    </init-param>
</filter>
<!-- 过滤所有请求 -->
<filter-mapping>
    <filter-name>CharacterEncodingFilter</filter-name>
    <url-pattern>*.do</url-pattern>
</filter-mapping>