声明:本文纯为个人笔记整理,如有不妥之处还望及时指出,欢迎转载!
只为解决操作问题,可以从第二幅图往后看!
一、做不出详细的概念叙述和文本设计,本文主要以实战步骤为主,少量解释为辅助,下面请大家牢记两幅图:
截图来自张开涛博客
典型的jsp(java server page)是一种服务器执行的组件,运行在标准HTML页面的java技术,最终还是被编译成服务器可以识别的servlet代码,生成.class文件,相比Servlet开发简洁、方便,缺点是视图显示、业务控制比较复杂,而且把对后端操作放在jsp页面很不安全;
故产生了Jsp+JavaBean开发,使用<jsp:usebean>标签,自动将请求封装为javabean组件,可以认为是为了增强jsp开发;这也是单一的开发思路,即下图所示,这种模型同样是没有本子上解决问题,大量的业务处理依然在jsp页面中,而bean负责的只有参数的请求处理;所以出现了我们的MVC模型;
jsp+bean模型

MVC模型
在JvavEE的开发中,可以认为下图就是我们的web mvc模型
控制器用servlet、模型用JavaBean、视图采用Jsp

二、下面开始步入正题;
进行springmvc开发,写业务逻辑之前,首先要做到:
1.开发环境(jdk+IDE+maven+mysql)
2.配置环境(web.xml、pom.xml、application.xml、springmvc.xml、mybatis.xml)
3.定义domian、生成dao、mapper
按照上述步骤进行开发,便于在后期调错,另外 可以个那好的梳理业务逻辑,本文只介绍,文件配置到连接上数据库。
三、SpringMvc开发用到的通用配置文件
1.pom.xml这里粘贴一个详细的pom文件,包含各种依赖和maven常用的几个插件
<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/maven-v4_0_0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>Traing</groupId> <artifactId>springmvc</artifactId> <packaging>war</packaging> <version>0.0.1-SNAPSHOT</version> <name>springmvc</name> <url>http://maven.apache.org</url> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <webVersion>2.3</webVersion> </properties> <dependencies> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-core</artifactId> <version>2.4.3</version> </dependency> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-databind</artifactId> <version>2.4.3</version> </dependency> <!--以下四个是SpringMvc中数据校验jar包jsr 303的相关依赖 --> <dependency> <groupId>org.hibernate</groupId> <artifactId>hibernate-validator</artifactId> <version>5.1.3.Final</version> </dependency> <dependency> <groupId>javax.validation</groupId> <artifactId>validation-api</artifactId> <version>1.1.0.Final</version> </dependency> <dependency> <groupId>org.jboss.logging</groupId> <artifactId>jboss-logging</artifactId> <version>3.1.1.GA</version> </dependency> <dependency> <groupId>org.glassfish</groupId> <artifactId>bean-validator</artifactId> <version>3.0-JBoss-4.0.2</version> <scope>provided</scope> </dependency> <dependency> <groupId>org.glassfish</groupId> <artifactId>javax.enterprise.deploy</artifactId> <version>3.0.1</version> <scope>provided</scope> </dependency> <dependency> <groupId>org.glassfish</groupId> <artifactId>javax.jms</artifactId> <version>3.0.1</version> <scope>provided</scope> </dependency> <dependency> <groupId>org.glassfish</groupId> <artifactId>javax.management.j2ee</artifactId> <version>3.0.1</version> <scope>provided</scope> </dependency> <dependency> <groupId>org.eclipse.persistence</groupId> <artifactId>javax.persistence</artifactId> <version>2.0.0</version> <scope>provided</scope> </dependency> <dependency> <groupId>org.glassfish</groupId> <artifactId>javax.resource</artifactId> <version>3.0.1</version> <scope>provided</scope> </dependency> <dependency> <groupId>org.glassfish</groupId> <artifactId>javax.security.auth.message</artifactId> <version>3.0.1</version> <scope>provided</scope> </dependency> <dependency> <groupId>org.glassfish</groupId> <artifactId>javax.security.jacc</artifactId> <version>3.0.1</version> <scope>provided</scope> </dependency> <dependency> <groupId>org.glassfish</groupId> <artifactId>javax.servlet</artifactId> <version>3.0.1</version> <scope>provided</scope> </dependency> <dependency> <groupId>org.glassfish</groupId> <artifactId>javax.servlet.jsp</artifactId> <version>3.0.1</version> <scope>provided</scope> </dependency> <dependency> <groupId>org.glassfish</groupId> <artifactId>javax.servlet.jsp.jstl</artifactId> <version>3.0.1</version> <scope>provided</scope> </dependency> <dependency> <groupId>javax.xml.bind</groupId> <artifactId>jaxb-api-osgi</artifactId> <version>2.2.1</version> <scope>provided</scope> </dependency> <dependency> <groupId>javax.ws.rs</groupId> <artifactId>jsr311-api</artifactId> <version>1.1.1</version> <scope>provided</scope> </dependency> <dependency> <groupId>org.glassfish.web</groupId> <artifactId>jstl-impl</artifactId> <version>1.2</version> <scope>provided</scope> </dependency> <dependency> <groupId>javax.mail</groupId> <artifactId>mail</artifactId> <version>1.4.3</version> <scope>provided</scope> </dependency> <dependency> <groupId>javax.xml</groupId> <artifactId>webservices-api-osgi</artifactId> <version>2.0.1</version> <scope>provided</scope> </dependency> <dependency> <groupId>org.jboss.weld</groupId> <artifactId>weld-osgi-bundle</artifactId> <version>1.0.1-SP3</version> <scope>provided</scope> </dependency> <dependency> <groupId>org.glassfish.web</groupId> <artifactId>javax.servlet.jsp.jstl</artifactId> <version>1.2.1</version> </dependency>
<!-- 项目其他依赖 -->
<!-- mysql 依赖 https://mvnrepository.com/artifact/mysql/mysql-connector-java --> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.23</version> </dependency> <!-- junit 依赖 --> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.12</version> <scope>test</scope> </dependency>
<!-- Mybatis --> <!-- https://mvnrepository.com/artifact/org.mybatis/mybatis --> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>3.2.1</version> </dependency> <!-- spring 依赖 --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context</artifactId> <version>3.2.18.RELEASE</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context-support</artifactId> <version>3.2.18.RELEASE</version> </dependency> <!-- https://mvnrepository.com/artifact/org.springframework/spring-test --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-test</artifactId> <version>3.2.18.RELEASE</version> <scope>test</scope> </dependency> <!-- https://mvnrepository.com/artifact/org.springframework/spring-core --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-core</artifactId> <version>3.2.18.RELEASE</version> </dependency> <!-- https://mvnrepository.com/artifact/org.springframework/spring-web --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-web</artifactId> <version>3.2.18.RELEASE</version> </dependency> <!-- https://mvnrepository.com/artifact/org.springframework/spring-aop --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-aop</artifactId> <version>3.2.18.RELEASE</version> </dependency>
<!-- https://mvnrepository.com/artifact/aspectj/aspectjweaver --> <dependency> <groupId>aspectj</groupId> <artifactId>aspectjweaver</artifactId> <version>1.5.4</version> </dependency>
<!-- https://mvnrepository.com/artifact/org.springframework/spring-tx --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-tx</artifactId> <version>3.2.18.RELEASE</version> </dependency> <!-- https://mvnrepository.com/artifact/org.springframework/spring-jdbc --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-jdbc</artifactId> <version>3.2.18.RELEASE</version> </dependency> <!-- https://mvnrepository.com/artifact/org.springframework/spring-orm --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-orm</artifactId> <version>3.2.18.RELEASE</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> <version>3.2.18.RELEASE</version> </dependency> <!-- spring mybatis 整合依赖 --> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis-spring</artifactId> <version>1.3.1</version> </dependency> <!--生成代码插件 --> <dependency> <groupId>org.mybatis.generator</groupId> <artifactId>mybatis-generator-core</artifactId> <version>1.3.3</version> <type>jar</type> </dependency> <!-- 连接池 --> <!-- https://mvnrepository.com/artifact/commons-dbcp/commons-dbcp -->
<dependency> <groupId>commons-dbcp</groupId> <artifactId>commons-dbcp</artifactId> <version>1.4</version> </dependency> <!-- https://mvnrepository.com/artifact/commons-pool/commons-pool --> <dependency> <groupId>commons-pool</groupId> <artifactId>commons-pool</artifactId> <version>1.6</version> </dependency> <!-- https://mvnrepository.com/artifact/org.apache.poi/poi --> <dependency> <groupId>org.apache.poi</groupId> <artifactId>poi</artifactId> <version>3.17</version> </dependency>
<!-- 文件上传 --> <!-- https://mvnrepository.com/artifact/commons-fileupload/commons-fileupload --> <dependency> <groupId>commons-fileupload</groupId> <artifactId>commons-fileupload</artifactId> <version>1.3</version> </dependency> <!-- https://mvnrepository.com/artifact/commons-io/commons-io --> <dependency> <groupId>commons-io</groupId> <artifactId>commons-io</artifactId> <version>2.6</version> </dependency> <!-- 导入c3p0依赖 --> <dependency> <groupId>com.mchange</groupId> <artifactId>mchange-commons-java</artifactId> <version>0.2.3.1</version> </dependency> <dependency> <groupId>c3p0</groupId> <artifactId>c3p0</artifactId> <version>0.9.1.2</version> </dependency>
<!-- log4j --> <dependency> <groupId>log4j</groupId> <artifactId>log4j</artifactId> <version>1.2.16</version> </dependency>
</dependencies> <build>
//打成jar时会自动打包依赖 <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-resources-plugin</artifactId> <configuration> <encoding>UTF-8</encoding> </configuration> </plugin>
<plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <configuration> <source>1.7</source> <target>1.7</target> <encoding>UTF-8</encoding> </configuration> </plugin> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-shade-plugin</artifactId> <version>1.4</version> <configuration> <createDependencyReducedPom>true</createDependencyReducedPom> </configuration> <executions> <execution> <phase>package</phase> <goals> <goal>shade</goal> </goals> <configuration> <transformers> <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer"> <mainClass>com.cmos.task.TaskManager</mainClass> </transformer> </transformers> </configuration> </execution> </executions> </plugin> </plugins>
</build> </project>
|
2.web.xml 需要注意其中两个配置文件 一个是application.xml :主要配置dataSource、dao、service等跟持久化相近的非webBean
一个是springmvc.xml:配置controller、handlerResolver视图解析器等web层组件

<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0"> <display-name>springmvc</display-name> <welcome-file-list> <welcome-file>/views/login.jsp</welcome-file> </welcome-file-list> <!-- 处理字符集编码 --> <filter> <filter-name>CharacterEncoding</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> <init-param> <param-name>forceEncoding</param-name> <param-value>true</param-value> </init-param> </filter> <filter-mapping> <filter-name>CharacterEncoding</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> <!-- 配置springmvc核心过滤器 --> <servlet> <servlet-name>dispatcher</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> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>dispatcher</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> <!-- 配置spring的web工厂 --> <listener> <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class> </listener> <context-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:/applicationContext.xml</param-value> </context-param> <!-- RESTful风格的配置:把POST请求转为PUT、DELETE请求--> <filter> <filter-name>HiddenHttpMethodFilter</filter-name> <filter-class>org.springframework.web.filter.HiddenHttpMethodFilter</filter-class> </filter> <filter-mapping> <filter-name>HiddenHttpMethodFilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping>
</web-app>
|
3.application.xml由于我主要用的注解驱动开发,所以这个配置文件没有相关的dao、servic的bean配置、我将mybatis的配置单独写在Mybatis.xml文件里,但是不要忘记引入到这里。如果只有数据库配置的话,也可以直接写进来(不建议)
4.Mybatis.xml 注意db.properties文件中的内容username、password注意不要配置的太通用 有可能会和本机的配置冲突
db.properties文件中的内容
driverClassName=com.mysql.jdbc.Driver url=jdbc:mysql://localhost:3306/studentmanager?useUnicode=true&characterEncoding=UTF-8 jdbcUserName=root jdbcPassword=root
Mybatis.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:tx="http://www.springframework.org/schema/tx" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd">
<context:property-placeholder location="classpath:db.properties"/> <!-- 配置数据源--> <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource"> <property name="driverClassName" value="${driverClassName}"> </property> <property name="url" value="${url}"> </property> <property name="username" value="${jdbcUserName}"> </property> <property name="password" value="${jdbcPassword}"> </property> </bean> <!--配置sqlSessionFactory--> <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"> <!-- 加载mybatis的全局配置文件 <property name="configLocation" value="classpath:mybatis/sqlMapConfig.xml"/> --> <!-- 数据库连接池 --> <property name="dataSource" ref="dataSource"/> <property name="mapperLocations" value="classpath:/Mapper/*Mapper.xml"> </property> <property name="typeAliasesPackage" value="classpath:com.cmos.domain"> </property> </bean>
<!-- mapper扫描器 --> <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"> <!-- 扫描包路径,如果需要扫描多个包,中间使用半角逗号隔开 --> <property name="basePackage" value="com.cmos.dao"/> <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/> </bean> <!-- 事务管理 --> <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"> <property name="dataSource" ref="dataSource"> </property> </bean> <!-- 使用annotation注解方式配置事务 --> <tx:annotation-driven transaction-manager="transactionManager"/> </beans>
|
5.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: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-3.2.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.2.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd">
<!-- 包含:webBean ViewResolver、handlerAdapter controller handlerMapping-->
<!-- 配置自定义扫描的包 -->
<context:component-scan base-package="com.cmos.controller,com.cmos.service,com.cmos.dao"/>
<!-- 配置视图解析器:如何把handler方法返回值解析为实际的物理视图 -->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/views/">
</property>
<property name="suffix" value=".jsp">
</property>
</bean>
<!-- default-servlet-handler 会在SpringMvc 上下文中定义一个DefaultServletHttpRequestHandler,
它会对进入DispatcherServlet的请求进行筛查,如果发现没有经过映射的请求,就将该请求交由web应用服务器
默认的Servlet处理,如果不是静态资源则用DispathcerServlet进行处理 -->
<mvc:default-servlet-handler/>
<mvc:annotation-driven>
</mvc:annotation-driven>
<!--拦截器-->
<mvc:interceptors>
<mvc:interceptor>
<mvc:mapping path="/district"/>
<mvc:mapping path="/organization"/>
<mvc:mapping path="/unit"/>
<mvc:mapping path="/student"/>
<!--com.coms...是我项目的包的名称不要误解 -->
<bean class="com.cmos.handlers.MyInterceptor"></bean>
</mvc:interceptor>
</mvc:interceptors>
<!-- 配置SimpleMappingExceptionResolver -->
<bean class="org.springframework.web.servlet.handler.SimpleMappingExceptionResolver">
<property name="exceptionMappings">
<props>
<prop key="java.lang.ArrayIndexOutOfBoundsException">error</prop>
</props>
</property>
</bean>
</beans>
6.dao和mapper.xml 我这里只粘了一个dao和mapper的样例
特别注意:
1.dao参数类型和Mapper的参数类型严格对称
2.mapper中的resultMap配置,前面是数据库字段名、后面是对应对象名,要严格一致
3.不要在Mybtais.xml中引入dao和mapper的位置
package com.cmos.dao;
import com.cmos.domain.District;
import org.apache.ibatis.annotations.Param;
import org.springframework.stereotype.Repository;
import java.util.List;
@Repository
public interface DistrictDao {
int deleteByPrimaryKey(Integer disId);
int insert(District record);
int updateByExample(@Param("example") District example);
List<District> selectAll();
}
Mapper.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.cmos.dao.DistrictDao">
<resultMap id="BaseResultMap" type="com.cmos.domain.District">
<id column="dis_id" jdbcType="INTEGER" property="disId" />
<result column="dis_name" jdbcType="VARCHAR" property="disName" />
</resultMap>
<select id="selectAll" resultMap="BaseResultMap">
select dis_id,dis_name from district
</select>
<delete id="deleteByPrimaryKey" parameterType="java.lang.Integer">
delete from district
where dis_id = #{disId,jdbcType=INTEGER}
</delete>
<insert id="insert" parameterType="com.cmos.domain.District">
insert into district (dis_id, dis_name)
values (#{disId,jdbcType=INTEGER}, #{disName,jdbcType=VARCHAR})
</insert>
<update id="updateByExample" parameterType="com.cmos.domain.District">
update district
set dis_name = #{example.disName,jdbcType=VARCHAR}
where dis_id = #{example.disId,jdbcType=INTEGER}
</update>
</mapper>
我的博客即将同步至腾讯云+社区,邀请大家一同入驻:https://cloud.tencent.com/developer/support-plan?invite_code=y5o4fpq222bt
- IDEA环境下SSM整合------注解开发
根据前一篇文章的步骤,目前项目进度应该是:核心过滤器配置完成.DispatcherServlet和ContextLoader配置完成.数据库dataSource配置完成.视图解析器配置完成.Mappe ...
- libCURL开源库在VS2010环境下编译安装,配置详解
libCURL开源库在VS2010环境下编译安装,配置详解 转自:http://my.oschina.net/u/1420791/blog/198247 http://blog.csdn.net/su ...
- 联想电脑win7旗舰版环境下的如何成功配置AppServ
联想电脑win7旗舰版环境下的如何成功配置AppServ 毕业设计中需要用Mysql数据库,并且想找一个方便Mysql数据库编程的开发工具,百度搜索了一下,AppServ集成环境安装包能快速搭建环境. ...
- 实验七:Xen环境下cirrOS的安装配置
实验名称: Xen环境下cirrOS的安装配置 实验环境: 这里的cirrOS和实验六中的busybox的启动方式相同,唯一的区别就是我们使用的cirrOS镜像中,已经包含了根文件系统.内核文件以及r ...
- 【转】mysql8.0 在window环境下的部署与配置
[转]mysql8.0 在window环境下的部署与配置 今天在阿里云window服务器上配置mysql环境,踩了一些坑,分享出来.需要的朋友可以看看.额,或许有人要吐槽我为什么不在linux上去配置 ...
- Linux环境下NodeJS的安装配置(HelloWorld)
Linux环境下NodeJS的安装配置(HelloWorld) 最简单的环境安装,测试helloworld.给初学者!! 安装脚本,请仔细阅读逐行执行: #!/bin/bash #检查是否已经安装 r ...
- GITHUB个人博客搭建-Pelican 在Windows环境下的安装及配置
GITHUB个人博客搭建-Pelican 在Windows环境下的安装及配置 前言 此篇博客主要为Pelican在Windows平台下的配置安装所写,在此过程中主要参考资料烟雨林博客.poem_of_ ...
- Mac 环境下svn服务器的配置
Mac 环境下svn服务器的配置 本文目录 • 一.创建代码仓库,用来存储客户端所上传的代码 • 二.配置svn的用户权限 • 三.使用svn客户端功能 在Windows环境中,我们一般使用Torto ...
- Java入门——在Linux环境下安装JDK并配置环境变量
Java入门——在Linux环境下安装JDK并配置环境变量 摘要:本文主要说明在Linux环境下JDK的安装,以及安装完成之后环境变量的配置. 使用已下载的压缩包进行安装 下载并解压 在Java的官网 ...
随机推荐
- [物理学与PDEs]第1章习题12 Coulomb 规范下电磁场的标势、矢势满足的方程
试给出在 Coulomb 规范下, 电磁场的标势 $\phi$ 与矢势 ${\bf A}$ 所满足的方程. 解答: 真空中的 Maxwell 方程组为 $$\bee\label{1_10_12:eq} ...
- MYSQL(三)
转载自https://www.cnblogs.com/wupeiqi/articles/5716963.html 1.索引 索引是表的目录,在查找内容之前可以先在目录中查找索引位置,以此快速定位查询数 ...
- Spring系列(五) 容器初始化过程源码
IoC/DI 的概念 容器是Spring的核心之一(另一个核心是AOP). 有了容器, IOC才可能实现. 什么使IoC? IoC就是将类自身管理的与其由依赖关系的对象的创建/关联和管理交予容器实现, ...
- Django 内置分页器
先导入Django内置的分页器 在商品列表页或者购物车列表页导入 在渲染list.html导入 然后在views后台渲染方法写入 打开list页面结果
- K-means clustering
K-means算法是一种迭代算法,步骤如下: 1.随机初始化K个聚类中心u1,u2,...,uk 2.根据每个样本和各个聚类中心的距离给每个样本打上标签(例如,x(i)与u3的距离最小,则x(i)的标 ...
- P5290 [十二省联考2019]春节十二响
题目地址:P5290 [十二省联考2019]春节十二响 骗分方法 如果你实在一点思路也没有,暴力都不会打,那么请考虑一下骗分. 方法一 输出所有 \(M\) 的和. 期望得分:0分. 实际还有5分 方 ...
- torch.utils.data.DataLoader对象中的迭代操作
关于迭代器等概念参考:https://www.cnblogs.com/zf-blog/p/10613533.html 关于pytorch中的DataLoader类参考:https://blog.csd ...
- 【原创】Linux基础之curl
http请求过程如下: # curl -v http://www.baidu.com % Total % Received % Xferd Average Speed Time Time Time C ...
- Python-爬虫-Beautifulsoup解析
简介 Beautiful Soup 是一个可以从HTML或XML文件中提取数据的Python库.它能够通过你喜欢的转换器实现惯用的文档导航,查找,修改文档的方式.Beautiful Soup会帮你节省 ...
- Java——super 与 this 关键字
super 与 this 关键字 super关键字:我们可以通过super关键字来实现对父类成员的访问,用来引用当前对象的父类. this关键字:指向自己的引用. package ti; public ...