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使用MySql触发器简化各表数据操作 触发器基本语法 生成一个触发器 CREATE TRIGGER 触发器名 触发事件(BEFORE|AFTER INSERT|UPDATE|DELETE) ON 表名 FOR EACH ROW 触发器激活后需要执行的语句一些注意事项 同一个数据库中不能创建同名触发器 在同一张表中不能出现触发条件相同的触发器 使用NEW和OLD来获取数据变化前后的记录值 如果激活后只有一条操作,可以直接写,如果需要复杂操作则需要使用BEGIN...END;语句包围 查看触发器 SHOW TRIGGERS ; 删除触发器 DROP TRIGGER 触发器名; 修改触发器 将已有触发器删除后再重新创建😂 一个简单的触发器示例 CREATE TRIGGER update_userinfo_trigger AFTER UPDATE ON user FOR EACH ROW BEGIN IF NEW.user_name <> OLD.user_name THEN UPDATE task_my SET user_name = NEW.user_name WHERE user_id = NEW.id; UPDATE table1 SET user_name = NEW.user_name WHERE user_id = NEW.id; UPDATE table2 SET user_name = NEW.user_name WHERE user_id = NEW.id; END IF; END;该触发器实现了,在更新user表中的name时,可以同时联动着将其他表中的name也更新掉,实现用户数据的统一 -
SSM开发环境搭建(小白自用) 前言 将SSM作为后端的的一个项目即将完工,在开发过程中踩了很多坑,与此同时也学习到了新知识,有了不小收获。在遇到麻烦和解决麻烦的路上,受到了很多分享教程博主的帮助。为了将帮助延续下去,我也将自己SSM环境配置的过程做了简单的纪录、分享。 系统软件版本 Windows 10 专业版 22H2 IntelliJ IDEA 2022.3.3 MySQL 8.0.32 Java 19.0.2 Spring 6.0.6 MyBatis 3.5.13 Tomcat 11.0.0 (软件系统版本不用完全一致,不同版本之间可能会出现一定程度的兼容性问题,可在有问题时在寻找对应版本的解决办法) 新建项目及项目配置 新建项目 使用IDEA新建一个空的默认Maven项目,并新建Java包完善SSM项目架构。 在新建controller包(表现层)、dao包(持久层)、service包(业务层) 在resources下新建db(存放数据库相关配置文件)、log(存放日志相关配置文件)、spring(存放与spring与其他整合相关配置文件) image-20230507141558542图片 修改Maven配置文件 使用默认Maven配置文件,在下载包时会比较慢,我们可以修改配置文件使用国内镜像来加速下载 IDEA内修改路径为File->Settings->Builde,Execution,Deployment->Maven 可以修改默认的文件,也可以重新使用一个自定义的配置文件,笔者这里使用了重新新建一个配置文件的方法。 image-20230507142114670图片 其中settings.xml文件中内容如下: <?xml version="1.0" encoding="UTF-8"?> <!-- Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file distributed with this work for additional information regarding copyright ownership. The ASF licenses this file to you under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. --> <!-- | This is the configuration file for Maven. It can be specified at two levels: | | 1. User Level. This settings.xml file provides configuration for a single user, | and is normally provided in ${user.home}/.m2/settings.xml. | | NOTE: This location can be overridden with the CLI option: | | -s /path/to/user/settings.xml | | 2. Global Level. This settings.xml file provides configuration for all Maven | users on a machine (assuming they're all using the same Maven | installation). It's normally provided in | ${maven.conf}/settings.xml. | | NOTE: This location can be overridden with the CLI option: | | -gs /path/to/global/settings.xml | | The sections in this sample file are intended to give you a running start at | getting the most out of your Maven installation. Where appropriate, the default | values (values used when the setting is not specified) are provided. | |--> <settings xmlns="http://maven.apache.org/SETTINGS/1.2.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.2.0 http://maven.apache.org/xsd/settings-1.2.0.xsd"> <!-- localRepository | The path to the local repository maven will use to store artifacts. | | Default: ${user.home}/.m2/repository <localRepository>/path/to/local/repo</localRepository> --> <!-- interactiveMode | This will determine whether maven prompts you when it needs input. If set to false, | maven will use a sensible default value, perhaps based on some other setting, for | the parameter in question. | | Default: true <interactiveMode>true</interactiveMode> --> <!-- offline | Determines whether maven should attempt to connect to the network when executing a build. | This will have an effect on artifact downloads, artifact deployment, and others. | | Default: false <offline>false</offline> --> <!-- pluginGroups | This is a list of additional group identifiers that will be searched when resolving plugins by their prefix, i.e. | when invoking a command line like "mvn prefix:goal". Maven will automatically add the group identifiers | "org.apache.maven.plugins" and "org.codehaus.mojo" if these are not already contained in the list. |--> <pluginGroups> <!-- pluginGroup | Specifies a further group identifier to use for plugin lookup. <pluginGroup>com.your.plugins</pluginGroup> --> </pluginGroups> <!-- proxies | This is a list of proxies which can be used on this machine to connect to the network. | Unless otherwise specified (by system property or command-line switch), the first proxy | specification in this list marked as active will be used. |--> <proxies> <!-- proxy | Specification for one proxy, to be used in connecting to the network. | <proxy> <id>optional</id> <active>true</active> <protocol>http</protocol> <username>proxyuser</username> <password>proxypass</password> <host>proxy.host.net</host> <port>80</port> <nonProxyHosts>local.net|some.host.com</nonProxyHosts> </proxy> --> </proxies> <!-- servers | This is a list of authentication profiles, keyed by the server-id used within the system. | Authentication profiles can be used whenever maven must make a connection to a remote server. |--> <servers> <!-- server | Specifies the authentication information to use when connecting to a particular server, identified by | a unique name within the system (referred to by the 'id' attribute below). | | NOTE: You should either specify username/password OR privateKey/passphrase, since these pairings are | used together. | <server> <id>deploymentRepo</id> <username>repouser</username> <password>repopwd</password> </server> --> <!-- Another sample, using keys to authenticate. <server> <id>siteServer</id> <privateKey>/path/to/private/key</privateKey> <passphrase>optional; leave empty if not used.</passphrase> </server> --> </servers> <!-- mirrors | This is a list of mirrors to be used in downloading artifacts from remote repositories. | | It works like this: a POM may declare a repository to use in resolving certain artifacts. | However, this repository may have problems with heavy traffic at times, so people have mirrored | it to several places. | | That repository definition will have a unique id, so we can create a mirror reference for that | repository, to be used as an alternate download site. The mirror site will be the preferred | server for that repository. |--> <mirrors> <!-- mirror | Specifies a repository mirror site to use instead of a given repository. The repository that | this mirror serves has an ID that matches the mirrorOf element of this mirror. IDs are used | for inheritance and direct lookup purposes, and must be unique across the set of mirrors. | <mirror> <id>mirrorId</id> <mirrorOf>repositoryId</mirrorOf> <name>Human Readable Name for this Mirror.</name> <url>http://my.repository.com/repo/path</url> </mirror> --> <mirror> <id>aliment</id> <name>aliyah maven</name> <url>https://maven.aliyun.com/nexus/content/groups/public/</url> <mirrorOf>central</mirrorOf> </mirror> <mirror> <id>uk</id> <mirrorOf>central</mirrorOf> <name>Human Readable Name for this Mirror.</name> <url>https://uk.maven.org/maven2/</url> </mirror> <mirror> <id>CN</id> <name>OSChina Central</name> <url>https://maven.oschina.net/content/groups/public/</url> <mirrorOf>central</mirrorOf> </mirror> <mirror> <id>nexus</id> <name>internal nexus repository</name> <!-- <url>http://192.168.1.100:8081/nexus/content/groups/public/</url>--> <url>https://repo.maven.apache.org/maven2</url> <mirrorOf>central</mirrorOf> </mirror> </mirrors> <!-- profiles | This is a list of profiles which can be activated in a variety of ways, and which can modify | the build process. Profiles provided in the settings.xml are intended to provide local machine- | specific paths and repository locations which allow the build to work in the local environment. | | For example, if you have an integration testing plugin - like cactus - that needs to know where | your Tomcat instance is installed, you can provide a variable here such that the variable is | dereferenced during the build process to configure the cactus plugin. | | As noted above, profiles can be activated in a variety of ways. One way - the activeProfiles | section of this document (settings.xml) - will be discussed later. Another way essentially | relies on the detection of a system property, either matching a particular value for the property, | or merely testing its existence. Profiles can also be activated by JDK version prefix, where a | value of '1.4' might activate a profile when the build is executed on a JDK version of '1.4.2_07'. | Finally, the list of active profiles can be specified directly from the command line. | | NOTE: For profiles defined in the settings.xml, you are restricted to specifying only artifact | repositories, plugin repositories, and free-form properties to be used as configuration | variables for plugins in the POM. | |--> <profiles> <!-- profile | Specifies a set of introductions to the build process, to be activated using one or more of the | mechanisms described above. For inheritance purposes, and to activate profiles via <activatedProfiles/> | or the command line, profiles have to have an ID that is unique. | | An encouraged best practice for profile identification is to use a consistent naming convention | for profiles, such as 'env-dev', 'env-test', 'env-production', 'user-jdcasey', 'user-brett', etc. | This will make it more intuitive to understand what the set of introduced profiles is attempting | to accomplish, particularly when you only have a list of profile id's for debug. | | This profile example uses the JDK version to trigger activation, and provides a JDK-specific repo. <profile> <id>jdk-1.4</id> <activation> <jdk>1.4</jdk> </activation> <repositories> <repository> <id>jdk14</id> <name>Repository for JDK 1.4 builds</name> <url>http://www.myhost.com/maven/jdk14</url> <layout>default</layout> <snapshotPolicy>always</snapshotPolicy> </repository> </repositories> </profile> --> <!-- | Here is another profile, activated by the system property 'target-env' with a value of 'dev', | which provides a specific path to the Tomcat instance. To use this, your plugin configuration | might hypothetically look like: | | ... | <plugin> | <groupId>org.myco.myplugins</groupId> | <artifactId>myplugin</artifactId> | | <configuration> | <tomcatLocation>${tomcatPath}</tomcatLocation> | </configuration> | </plugin> | ... | | NOTE: If you just wanted to inject this configuration whenever someone set 'target-env' to | anything, you could just leave off the <value/> inside the activation-property. | <profile> <id>env-dev</id> <activation> <property> <name>target-env</name> <value>dev</value> </property> </activation> <properties> <tomcatPath>/path/to/tomcat/instance</tomcatPath> </properties> </profile> --> </profiles> <!-- activeProfiles | List of profiles that are active for all builds. | <activeProfiles> <activeProfile>alwaysActiveProfile</activeProfile> <activeProfile>anotherAlwaysActiveProfile</activeProfile> </activeProfiles> --> </settings> 只是修改了mirrors部分,使用了阿里云镜像加速国内下载速度。 设置项目所需包 修改pom.xml文件,以下内容为本人使用成功的配置文件内容,仅作参考 <?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>com.mango</groupId> <artifactId>ssmTest</artifactId> <version>1.0-SNAPSHOT</version> <properties> <!-- 工程编译版本,一般与安装的JDK版本一致--> <maven.compiler.source>19</maven.compiler.source> <maven.compiler.target>19</maven.compiler.target> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <!--统一的版本管理--> <spring.version>6.0.6</spring.version> <slf4j.version>2.0.5</slf4j.version> <mysql.version>8.0.32</mysql.version> <mybatis.version>3.5.13</mybatis.version> </properties> <dependencies> <!-- spring --> <dependency> <groupId>org.aspectj</groupId> <artifactId>aspectjweaver</artifactId> <version>1.9.19</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-aop</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-web</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-test</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-tx</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-jdbc</artifactId> <version>${spring.version}</version> </dependency> <!--Junit--> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.13.2</version> <scope>compile</scope> </dependency> <!--数据库驱动--> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>${mysql.version}</version> </dependency> <!-- 数据库连接池 --> <dependency> <groupId>c3p0</groupId> <artifactId>c3p0</artifactId> <version>0.9.1.2</version> <type>jar</type> <scope>compile</scope> </dependency> <!--Servlet - JSP --> <dependency> <groupId>javax.servlet</groupId> <artifactId>servlet-api</artifactId> <version>2.5</version> <scope>provided</scope> </dependency> <dependency> <groupId>javax.servlet.jsp</groupId> <artifactId>jsp-api</artifactId> <version>2.0</version> <scope>provided</scope> </dependency> <dependency> <groupId>jstl</groupId> <artifactId>jstl</artifactId> <version>1.2</version> </dependency> <!-- @Resource注解依赖包--> <dependency> <groupId>javax.annotation</groupId> <artifactId>javax.annotation-api</artifactId> <version>1.3.2</version> </dependency> <!--Mybatis--> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>${mybatis.version}</version> </dependency> <!-- Spring整合ORM --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-orm</artifactId> <version>6.0.6</version> </dependency> <!-- spring整合mybatis--> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis-spring</artifactId> <version>3.0.1</version> </dependency> <!-- log --> <dependency> <groupId>org.apache.logging.log4j</groupId> <artifactId>log4j</artifactId> <version>2.20.0</version> <type>pom</type> </dependency> <dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-api</artifactId> <version>${slf4j.version}</version> </dependency> <dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-log4j12</artifactId> <version>${slf4j.version}</version> </dependency> <!--加入对json转换--> <!-- JSON: jackson --> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-annotations</artifactId> <version>2.14.2</version> </dependency> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-core</artifactId> <version>2.14.2</version> </dependency> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-databind</artifactId> <version>2.14.2</version> </dependency> <dependency> <groupId>com.fasterxml.jackson.jr</groupId> <artifactId>jackson-jr-all</artifactId> <version>2.14.2</version> </dependency> <dependency> <groupId>com.alibaba</groupId> <artifactId>fastjson</artifactId> <version>2.0.25</version> </dependency> <dependency> <groupId>com.alibaba</groupId> <artifactId>druid</artifactId> <version>1.2.16</version> </dependency> <!-- http请求--> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-webflux</artifactId> <version>3.0.4</version> </dependency> </dependencies> <build> <resources> <resource> <directory>src/main/java</directory> <includes> <include>**/*.properties</include> <include>**/*.xml</include> </includes> <filtering>false</filtering> </resource> <resource> <directory>src/main/resources</directory> </resource> </resources> </build> </project> 添加Web模块 File->Project Structure->Modules 如图操作 image-20230507143328815图片 添加后内容保持默认,确认后即可导入web模块 安装Tomcat 可以参考以下教程 {% link Wxy1122.,[IntelliJ IDEA中配置Tomcat(超详细)_idea配置tomcat_Wxy1122.的博客-CSDN博客,https://blog.csdn.net/Wxy971122/article/details/123508532 %} SSM配置文件 jdbc配置文件 在resources->db下新建jdbc.properties文件,其中内容参考如下 jdbc.driver = com.mysql.cj.jdbc.Driver jdbc.url = jdbc:mysql://localhost:3306/xxx?useUnicode=true&characterEncoding=utf-8&useSSL=false&serverTimezone=GMT jdbc.username = root jdbc.password = root由于使用的MySQL版本为8,所以驱动才使用为com.mysql.cj.jdbc.Driver,由于没有在MySQL中做过测试,不能确定在MySQL 5中也能正常使用 jdbc.url中的xxx用自己数据库名称替换 新建mybatis控制文件 在db下新建mybatis.xml文件 由于大部分和MyBatis相关配置文件都会和Spring的配置文件整合到一起,这里的Mybatis控制文件只起到辅助作用,参考代码如下: <?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd"> <configuration> <!-- 开启延迟加载 该项默认为false,即所有关联属性都会在初始化时加载 true表示延迟按需加载 --> <settings> <setting name="lazyLoadingEnabled" value="true"/> <!-- 开启二级缓存 --> <setting name="cacheEnabled" value="true"/> </settings> </configuration> Spring整合MyBatis 在resources->spring下新建applicationContext.xml文件,将Spring和MyBatis配置文件整合在一起,参考代码如下: <?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:tx="http://www.springframework.org/schema/tx" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd"> <!-- 开启注解扫描,要扫描的是service和dao层的注解,要忽略web层注解,因为web层让SpringMVC框架去管理 --> <context:component-scan base-package="com.mango"> <!-- 配置要忽略的注解 --> <context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller"/> </context:component-scan> <!-- 引入配置文件 --> <bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer"> <property name="location" value="classpath:db/jdbc.properties" /> </bean> <!--Spring整合Mybatisl框架--> <!-- 配置C3P0的连接池对象 --> <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource"> <property name="driverClassName" value="${jdbc.driver}"/> <property name="url" value="${jdbc.url}"/> <property name="username" value="${jdbc.username}"/> <property name="password" value="${jdbc.password}"/> </bean> <!-- 配置SessionFactory的Bean --> <bean id="sessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"> <!-- 注入数据源 --> <property name="dataSource" ref="dataSource"/> <!-- 指定MyBatis配置文件的位置 --> <property name="configLocation" value="classpath:db/mybatis.xml"/> <!-- 给实体类起别名 --> <property name="typeAliasesPackage" value="com.mango.entity"/> </bean> <!-- 配置mapper接口的扫描器,将Mapper接口的实现类自动注入到IoC容器中 实现类Bean的名称默认为接口类名的首字母小写 --> <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"> <!-- basePackage属性指定自动扫描mapper接口所在的包 --> <property name="basePackage" value="com.mango.dao"/> </bean> <!--SqlMapConfig.xml和jdbcConfig.properties可以删除了--> <!--配置Spring框架声明式事务管理--> <!--配置事务管理器--> <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"> <property name="dataSource" ref="dataSource"></property> </bean> <!-- 配置事务的通知 --> <tx:advice id="txAdvice" transaction-manager="transactionManager"> <tx:attributes> <tx:method name="find*" propagation="SUPPORTS" read-only="true"/> <tx:method name="*" isolation="DEFAULT"/> </tx:attributes> </tx:advice> <!-- 配置AOP增强 --> <aop:config> <!-- <aop:advisor advice-ref="txAdvice" pointcut="execution(* com.mango.service.impl.*.*(..))"/>--> <!-- 配置切入点表达式 --> <aop:pointcut expression="execution(* com.mango.service.impl.*.*(..))" id="pt1"/> <!-- 建立通知和切入点表达式的关系 --> <aop:advisor advice-ref="txAdvice" pointcut-ref="pt1"/> </aop:config> </beans> Springmvc配置文件 在resources->spring下新建springmvc.xml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: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-4.0.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd"> <!-- 配置@controller扫描包 --> <context:component-scan base-package="com.mango.controller" /> <!--使用Annotation自动注册Bean,扫描@Controller和@ControllerAdvice--> <context:component-scan base-package="com.mango" use-default-filters="false"> <!-- base-package 如果多个,用“,”分隔 --> <context:include-filter type="annotation" expression="org.springframework.stereotype.Controller" /> <!--控制器增强,使一个Controller成为全局的异常处理类,类中用@ExceptionHandler方法注解的方法可以处理所有Controller发生的异常--> <context:include-filter type="annotation" expression="org.springframework.web.bind.annotation.ControllerAdvice" /> </context:component-scan> <!-- 配置注解驱动,相当于同时使用最新处理器映射跟处理器适配器,对json数据响应提供支持 --> <mvc:annotation-driven /> <!-- 输出对象转JSON支持 --> <bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter"> <property name="messageConverters"> <list> <bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter"> <property name="supportedMediaTypes"> <list> <value>text/html;charset=UTF-8</value> <value>text/plain;charset=UTF-8</value> <value>application/json;charset=UTF-8</value> </list> </property> </bean> </list> </property> </bean> <!-- 配置视图解析器 --> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="prefix" value="/WEB-INF/jsp/"/> <property name="suffix" value=".jsp"/> </bean> </beans> web模块控制文件 编辑web->WEB-INF->web.xml文件,内容如下 <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_3_1.xsd" version="3.1"> <!-- 配置前端控制器 --> <servlet> <servlet-name>springmvc</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <!-- 指定配置文件位置和名称 如果不设置,默认找/WEB-INF/<servlet-name>-servlet.xml --> <init-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:spring/springmvc.xml</param-value> </init-param> <load-on-startup>1</load-on-startup> <async-supported>true</async-supported> </servlet> <servlet-mapping> <servlet-name>springmvc</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> <!-- 配置 spring 提供的监听器,用于启动服务时加载容器 。 该监听器只能加载 WEB-INF 目录中名称为 applicationContext.xml 的配置文件 --> <listener> <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class> </listener> <!-- 手动指定 spring 配置文件位置 --> <context-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:spring/applicationContext.xml</param-value> </context-param> </web-app> 日志配置 在resources->log下新建log4j.properties log4j.rootLogger=DEBUG, stdout log4j.appender.stdout=org.apache.log4j.ConsoleAppender log4j.appender.stdout.layout=org.apache.log4j.PatternLayout log4j.appender.stdout.layout.ConversionPattern=%5p %d %C: %m%n log4j.logger.java.sql.ResultSet=INFO log4j.logger.org.apache=INFO log4j.logger.java.sql.Connection=DEBUG log4j.logger.java.sql.Statement=DEBUG log4j.logger.java.sql.PreparedStatement=DEBUG 测试 在test->java下更具需求新建测试类 新建测试数据库test,其中有表student(id,name,age) 在之前新建的entity包中新建Student的实现类(getter、setter方法以省略) package com.mango.entity; public class Student { private int id; private String name; private String age; @Override public String toString() { return "Student{" + "id=" + id + ", name='" + name + '\'' + ", age='" + age + '\'' + '}'; } } 对Spring和MyBatis整合配置测试 在包dao中新建学生接口StudentDao.java package com.mango.dao; import com.mango.entity.Student; import java.util.List; public interface StudentDao { public List<Student> findAll(); }在同样位置新建同名mapper文件StudentDao.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"> <!--命名空间为StudentDao接口--> <mapper namespace="com.mango.dao.StudentDao"> <!-- id为接口中的方法名--> <select id="findAll">SELECT * FROM Student</select> </mapper>在service包中新建service接口和实现类 image-20230507154913975图片 学生业务层接口StudentService.java package com.mango.service; import com.mango.entity.Student; import org.springframework.stereotype.Service; import java.util.List; //千万不要忘记添加Service注解 @Service public interface StudentService { public List<Student> findAll(); }实现类StudentServiceImpl.java package com.mango.service.impl; import com.mango.dao.StudentDao; import com.mango.entity.Student; import com.mango.service.StudentService; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service; import java.util.List; @Service public class StudentServiceImpl implements StudentService { @Autowired private StudentDao studentDao; public List<Student> findAll(){ return studentDao.findAll(); } }在test中新建Spring和MyBatis整合测试代码SpringMyBatis.java import com.mango.entity.Student; import com.mango.service.StudentService; import org.junit.Test; import org.junit.runner.RunWith; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.test.context.ContextConfiguration; import org.springframework.test.context.junit4.SpringJUnit4ClassRunner; import java.util.List; @RunWith(SpringJUnit4ClassRunner.class) @ContextConfiguration(locations="classpath:spring/applicationContext.xml") public class SpringMyBatis { @Autowired private StudentService studentService; @Test public void test(){ List<Student> studentList=studentService.findAll(); for (Student student:studentList){ System.out.println(student.toString()); } } } image-20230507161529932图片 测试成功 Spring整合SpringMVC测试 在Controller包中新建StudentController.java package com.mango.controller; import com.mango.service.StudentService; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; import org.springframework.web.bind.annotation.ResponseBody; //千万不要忘记@Controller @Controller @RequestMapping public class StudentController { @Autowired private StudentService studentService; @RequestMapping(value = "/test" ,method = RequestMethod.GET) @ResponseBody public Object test(){ return studentService.findAll(); } } 将项目打包File->Project Structure->Artifacts image-20230507162236159图片 如果有出现部分包不完全可以下图操作 image-20230507162342826图片 修改Tomcat配置(已正确安装Tomcat的情况下) image-20230507162648849图片 image-20230507162740440图片 启动Tomcat后在浏览器中访问localhost:8080/test 不报错有返回值,说明Spring整合SpringMVC配置成功。 image-20230507163245993图片 -
MySql入门基础命令 {% note info simple %} 该文章为个人学习笔记,内容仅供参考 {% endnote %} 主要参考以下两个网站 {% flink %} class_name: 参考网站 class_desc: link_list: name: MySQL 5.1中文文档 link: https://www.mysqlzh.com/ avatar: https://www.mysqlzh.com/Application/Home/View/Public/img/mysql-logo.svg descr: MySql中文网 name: 易百教程 link: https://www.yiibai.com/ avatar: https://www.yiibai.com/static/img/logo.png descr: 专注于IT教程和实例 {% endflink %} 连接数据库 mysql -h hostname -u user -phost:当前服务器主机名 user:用户名 密码:可以直接在p后面直接跟密码,如:-ppasswords;还可以p后留空回车后再输入密码。推荐使用后者,这样更安全。 创建数据库 创建一个新数据库 CREATE DATABASE [IF NOT EXISTS] dbname;显示数据库 SHOW DATABASES;选择数据库 USE dbname # 或者在连接时选择 mysql -h hostname -u user -p dbname创建表 查看数据库中的表 SHOW TABLES;创建新表 CREATE TABLE tableName (listing1 dataType default value listingConstraint, listing2 dataType default value listingConstraint, listing3 dataType default value listingConstraint, listing4 dataType default value listingConstraint, ......, tableConstraint );表名tableName在一个数据库中必须是唯一的,括号内的内容是对每一列的列名和属性的定义通过‘,’隔开每一列,最后一列是对表的约束‘,’可以省略。 表被创建好后可以使用DESCRIBE来查看表中的列名和数据类型等属性。 DESCRIBE TABLES;image-20220511172552158图片 对表中数据的管理 查找数据 SELECT 查询内容 FROM 数据表 WHERE 查询条件; 查询内容可以是表中的一列或多列,* 则表示查询表中所有的列 所查询的数据表应为当前数据库中存在的表 查询条件可以做出合适的限定,从而只返回我们想要的数据 在查询NULL内容时,WHERE后的条件不是"列=NULL",而是"列 IS NULL" 增加数据 # 单次添加一个新记录 INSERT INTO 数据表 (列名) VALUES (数据内容); 列名与数据内容要一一对应 如果每一列都要添加数据,列名可以省略,此时的数据内容则要包含每一列数据 数据内容如果是多项用‘,'隔开 # 单次添加多个新纪录 LOAD DATA LOCAL INFILE 'fileName' INTO TABLE tableName; 将要添加的数据保存到文本文件中,每行表示一个新记录,用定位符(Tab)把每一列分隔开,对于NULL值使用\N来代替。 删除数据 DELETE FROM 表名 WHERE 删除条件; WHERE 删除条件可以省略,表示删除表中所有行 修改数据 UPDATE 表名 SET 列名1=值1, 列名2=值2, ..., WHERE 条件; SET 后可修改多列,以','分隔开 WHERE 条件可以省略,省略后表示修改所有行中的数据 -
搭建私人云盘 准备 硬件: 树莓派4B 机械硬盘 软件: Nginx PHP MySql nextcloud 选用树莓派是由于手头上刚好有一块树莓派,为了不让他吃灰;实际上可以选择旧电脑,或者云服务器。 软件安装 安装nginx $sudo apt install nginx -y安装完成后在浏览器中输入树莓派的IP地址,可以看到如下界面 image-20220219132349742图片 安装PHP7.4 目前最新的PHP版本好像是7.4版本,也可以选择其他版本,将php7.4后面的7.4改成对应的版本哈就可以安装其他版本的PHP sudo apt install php7.4 php7.4-fpm php7.4-cli php7.4-curl php7.4-gd php7.4-cgi php7.4-xml php7.4-dom php7.4-zip php7.4-intl php7.4-mbstring php7.4-mysql -y安装并配置MySql $sudo apt install mariadb-server $sudo mysql_secure_installation此时系统会询问你:Enter current password for root (enter for none): ,按回车(enter)键,因为第一次登陆是没有密码的。 然后会询问你: Set root password? —— 按 y ,进行root帐号的密码设置 此时,会提示 New password ,在此输入你的MySQL密码,请牢记这个密码,输入完成按回车,会提示re-enter new password此时再重复输入密码,回车即可。 然后,询问你 Remove anonymous users ,按 y 。 然后,询问你 Disallow root login remotely ,按 y 。 然后,询问你 Remove test database and access to it ,按 y 。 然后,询问你 Reload privilege tables now ,按 y 。 最后,您将看到消息 All done! 和 Thanks for using MariaDB! 。表示已经设置完成了。 sudo mysql -u root -p #输入密码后: # 创建数据库 CREATE DATABASE IF NOT EXISTS nextcloud DEFAULT CHARACTER SET UTF8 COLLATE utf8_general_ci; # 创建用户 GRANT ALL PRIVILEGES ON nextcloud.* to '用户名'@'127.0.0.1' identified by '密码'; # 刷新数据库 FLUSH PRIVILEGES; 配置软件 配置Nginx $sudo vim /etc/nginx/sites-available/defaultnginx默认的网站代理地址是在var/www/html下,可以保留使用原来的,也可以修改到自己新建的地址下。如果选择新建不要忘记去确保指定的路径下的文件夹要存在。像我的就要在/var下新建owncloud文件夹。sudo mkdir /var/owncloud image-20220219194922636图片 location / { index index.html index.htm index.php default.html default.htm default.php; if (-f $request_filename/index.html){ rewrite (.*) $1/index.html break; } if (-f $request_filename/index.php){ rewrite (.*) $1/index.php; } if (!-f $request_filename){ rewrite (.*) /index.php; } }去掉location ~ \ .php上的注释 image-20220219195040903图片 给根目录权限 # 给权限 sudo chmod -R 755 /var/owncloud sudo chown -R www-data:www-data /var/owncloud #重启nginx sudo systemctl restart nginx在刚刚网站指定的目录下新建PHP测试文件 $sudo vim /var/owncloud/index.php #输入以下代码 <?php phpinfo(); ?>重新启动Nginx:$sudo systemctl restart nginx 可能报错: “Job for nginx.service failed because the control process exited with error code. See "systemctl status nginx.service" and "journalctl -xe" for details.” 多检查修改过的地方,是否有单词错误,或者是否有分号,括号是否对应... Nginx代理php成功后,在浏览器输入树莓派IP地址后能看到如下界面说明配置成功。 image-20220219141927075图片 安装nextCloud 进入刚刚配置的代理目录:cd /var/nextcloud 将刚刚的测试文件删除: sudo rm * 下载nextcloud) sudo wget https://download.nextcloud.com/server/releases/nextcloud-23.0.2.tar.bz2这是目前最新版本,请自己到官网查看版本 image-20220219192510883图片 # 解压缩: sudo tar -jxvf nextcloud-23.0.2.tar.bz2 nextcloud # 复制出来 sudo cp -rf nextcloud/* /var/owncloud再访问IP地址就可以看到NextCloud的运行界面了 image-20220219200624789图片