Redis與資料庫之間的處理
阿新 • • 發佈：2021-07-20
·前言
剛通過視訊學完mybatis、spring、springMVC，做了一個SSM框架的整合。此框架是結合了視訊中老師的思路，按照自己的理解進行整合的。這是原出處：http://dwz.date/ac27。框架設計了一個圖書表，並可以通過前端web頁面對圖書表進行增刪改查等操作。由於沒有前端基礎，頁面比較簡陋。同時，程式碼不夠規範，大小寫格式沒有按照規範來。希望以後可以注意到並改正。
·整合步驟：
（1）通過maven建立一個不使用模板的專案，設定GAV（groupId、artifactId、version），並把專案設定成web專案
（2）建立資料庫 :
CREATE TABLE `books` ( `bookID`INT(10) NOT NULL AUTO_INCREMENT COMMENT '書id', `bookName` VARCHAR(100) NOT NULL COMMENT '書名', `bookCounts` INT(11) NOT NULL COMMENT '數量', `detail` VARCHAR(200) NOT NULL COMMENT '描述', KEY `bookID` (`bookID`) ) ENGINE=INNODB DEFAULT CHARSET=utf8
（3）匯入依賴包，在pom.xml中配置：
<dependencies> <!--Junit--> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.12</version> </dependency> <!--資料庫驅動--> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.47</version> </dependency> <!-- 資料庫連線池 --> <dependency> <groupId>com.mchange</groupId> <artifactId>c3p0</artifactId> <version>0.9.5.2</version> </dependency> <!--Servlet - JSP --> <dependency> <groupId>javax.servlet</groupId> <artifactId>servlet-api</artifactId> <version>2.5</version> </dependency> <dependency> <groupId>javax.servlet.jsp</groupId> <artifactId>jsp-api</artifactId> <version>2.2</version> </dependency> <dependency> <groupId>javax.servlet</groupId> <artifactId>jstl</artifactId> <version>1.2</version> </dependency> <!--Mybatis--> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>3.5.2</version> </dependency> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis-spring</artifactId> <version>2.0.2</version> </dependency> <!--Spring--> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> <version>5.1.9.RELEASE</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-jdbc</artifactId> <version>5.1.9.RELEASE</version> </dependency> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <version>1.18.20</version> </dependency> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-databind</artifactId> <version>2.12.4</version> </dependency> </dependencies>
（4）設定靜態資源過濾，在pom.xml中配置:
<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> <includes> <include>**/*.properties</include> <include>**/*.xml</include> </includes> <filtering>false</filtering> </resource> </resources> </build>
（5）建立專案基本結構（建立每一層的包）：
entity、dao、service、controller
（6）建立基礎框架配置：
1.在resources資料夾中建立mybatis-config.xml
<?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> </configuration>
2.在resources資料夾中建立applicationContext.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"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd"> </beans>
（7）在resources資料夾中建立資料庫配置檔案 database.properties：
jdbc.driver=com.mysql.jdbc.Driver jdbc.url=jdbc:mysql://localhost:3306/ssmbuilduseSSL=true&useUnicode=true&characterEncoding=utf8 jdbc.username=root jdbc.password=123
（8）IDEA關聯資料庫
（9）編寫實體類：在entity下建立Books類：
package com.zyf.entity; import lombok.AllArgsConstructor; import lombok.Data; import lombok.NoArgsConstructor; @Data @AllArgsConstructor @NoArgsConstructor public class Books { private int bookID; private String bookName; private int bookCounts; private String detail; }
（10）編寫dao層的BooksMapper介面：
package com.zyf.dao; import com.zyf.entity.Books; import org.apache.ibatis.annotations.Param; import java.util.List; public interface BooksMapper { int addBooks(Books books); int deleteBooks(@Param("bookID") int id); int updateBooks(Books books); Books queryBooksById(@Param("bookID")int id); List<Books> queryAllBooks(); }
（11）編寫BooksMapper.xml實現介面BooksMapper：
<?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.zyf.dao.BooksMapper"> <insert id="addBooks" parameterType="Books"> insert into mybatis.books values (#{bookID},#{bookName},#{bookCounts},#{detail}); </insert> <delete id="deleteBooks" parameterType="int"> delete from mybatis.books where bookID=#{bookID}; </delete> <update id="updateBooks" parameterType="Books"> update mybatis.books set bookName = #{bookName},bookCounts=#{bookCounts},detail=#{detail} where bookID=#{bookID}; </update> <select id="queryBooksById" resultType="Books"> select * from mybatis.books where bookID=#{bookID}; </select> <select id="queryAllBooks" resultType="Books"> select * from mybatis.books; </select> </mapper>
在編寫該程式碼的時候，需要在resources/mybatis-config.xml中，定義別名以及註冊該mapper.xml：
<typeAliases> <package name="com.zyf.entity"/> </typeAliases> <mappers> <mapper resource="com/zyf/dao/BooksMapper.xml"/> </mappers>
（12）編寫service層BooksService介面：
package com.zyf.service; import com.zyf.entity.Books; import java.util.List; public interface BooksService { int addBooks(Books books); int deleteBooks(int id); int updateBooks(Books books); Books queryBooksById(int id); List<Books> queryAllBooks(); }
（13）編寫service層BooksService的實現類BooksServiceImpl：
package com.zyf.service; import com.zyf.dao.BooksMapper; import com.zyf.entity.Books; import java.util.List; public class BooksServiceImpl implements BooksService{ //呼叫dao層的操作，設定一個set介面，方便Spring管理 private BooksMapper booksMapper; public void setBooksMapper(BooksMapper booksMapper){ this.booksMapper=booksMapper; } public int addBooks(Books books) { return booksMapper.addBooks(books); } public int deleteBooks(int id) { return booksMapper.deleteBooks(id); } public int updateBooks(Books books) { return booksMapper.updateBooks(books); } public Books queryBooksById(int id) { return booksMapper.queryBooksById(id); } public List<Books> queryAllBooks() { return booksMapper.queryAllBooks(); } }
（14）編寫resources/applicationContext.xml檔案：
<?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.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"> <!--1.關聯資料庫配置檔案--> <context:property-placeholder location="classpath:database.properties"/> <!--2.注入資料庫連線池--> <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"> <!--連線池屬性--> <property name="driverClass" value="${jdbc.driver}"/> <property name="jdbcUrl" value="${jdbc.url}"/> <property name="user" value="${jdbc.username}"/> <property name="password" value="${jdbc.password}"/> <!-- c3p0連線池的私有屬性 --> <property name="maxPoolSize" value="30"/> <property name="minPoolSize" value="10"/> <!-- 關閉連線後不自動commit --> <property name="autoCommitOnClose" value="false"/> <!-- 獲取連線超時時間 --> <property name="checkoutTimeout" value="10000"/> <!-- 當獲取連線失敗重試次數 --> <property name="acquireRetryAttempts" value="2"/> </bean> <!--3.配置SqlSessionFactory物件,設定連線池和mybatis配置檔案的位置--> <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"> <property name="dataSource" ref="dataSource"/> <property name="configLocation" value="classpath:mybatis-config.xml"/> </bean> <!--4.MapperScannerConfigurer 自動掃描 將Mapper介面生成代理注入到Spring--> <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"> <property name="basePackage" value="com.zyf.dao"/> </bean> <!--5.將BookServiceImpl注入到容器中--> <!--當使用註解的方式注入時候，需要加入掃描程式碼<context:component-scan base-package="com.zyf.service" />--> <bean id="BookServiceImpl" class="com.zyf.service.BooksServiceImpl"> <property name="booksMapper" ref="booksMapper"/> </bean> <!--6.配置事務管理器--> <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"> <property name="dataSource" ref="dataSource"/> </bean> <!--截止到6mybatis已經整合完畢，從7開始配置SpringMVC，即控制層以及請求等等的相關內容--> <!--7.開啟springMVC註解驅動,並設定JSON為utf-8--> <mvc:annotation-driven> <mvc:message-converters> <bean class="org.springframework.http.converter.StringHttpMessageConverter"> <property name="supportedMediaTypes"> <list> <value>text/html;charset=utf-8</value> </list> </property> </bean> </mvc:message-converters> </mvc:annotation-driven> <!--8..靜態資源預設servlet配置--> <mvc:default-servlet-handler/> <!--9.由於使用了註解所以需要掃描--> <context:component-scan base-package="com.zyf.controller"/> <!--10.配置檢視解析器--> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="viewClass" value="org.springframework.web.servlet.view.JstlView"/> <property name="prefix" value="/WEB-INF/jsp/"/> <property name="suffix" value=".jsp"/> </bean> </beans>
（15）編寫web.xml配置：
<!--設定前端控制器--> <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:applicationContext.xml</param-value> </init-param> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>dispatcherServlet</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> <!--設定過濾器，此為一個編碼型別的設定--> <filter> <filter-name>encodingFilter</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> </filter> <filter-mapping> <filter-name>encodingFilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> <!--設定一個session的過期時間--> <session-config> <session-timeout>15</session-timeout> </session-config>
（16）編寫控制層BooksController：
package com.zyf.controller; import com.zyf.entity.Books; import com.zyf.service.BooksService; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.beans.factory.annotation.Qualifier; import org.springframework.stereotype.Controller; import org.springframework.ui.Model; import org.springframework.web.bind.annotation.PathVariable; import org.springframework.web.bind.annotation.RequestMapping; import java.util.List; @Controller @RequestMapping("/Books") public class BooksController { @Autowired @Qualifier("BookServiceImpl") private BooksService booksService; @RequestMapping("/All") public String queryAllBooks(Model model) { List<Books> list = booksService.queryAllBooks(); model.addAttribute("books", list); return "AllBooks"; } @RequestMapping("/toAddBooks") public String toAddBooks() { //使用此方法，可以跳轉到WEB-INF下面的jsp頁面 return "AddBooks"; } @RequestMapping("/AddBooks") public String AddBooks(Books books) { System.out.println(books); booksService.addBooks(books); return "redirect:/Books/All"; } @RequestMapping("/DeleteBooks/{bookID}") public String DeleteBooks(@PathVariable("bookID") int bookID) { booksService.deleteBooks(bookID); return "redirect:/Books/All"; } @RequestMapping("/toUpdate") public String toUpdate(int id, Model model) { Books books = booksService.queryBooksById(id); model.addAttribute("books", books); return "UpdateBooks"; } @RequestMapping("/UpdateBooks") public String UpdateBooks(Books books) { booksService.updateBooks(books); return "redirect:/Books/All"; } }
（17）編寫前端:1.主頁面（index.jsp）：
<%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>$Title$</title> </head> <body> <a href="${pageContext.request.contextPath}/Books/All">檢視所有書籍</a> </body> </html>
2.展示所有書籍頁面（AllBooks.jsp）：
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %> <%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>展示所有書籍</title> </head> <body> <p><a href="${pageContext.request.contextPath}/Books/toAddBooks">新增書籍</a></p> <table> <thead> <tr> <th>書籍編號</th> <th>書籍名字</th> <th>書籍數量</th> <th>書籍詳情</th> <th>操作</th> </tr> </thead> <tbody> <c:forEach var="book" items="${books}"> <tr> <th>${book.bookID}</th> <th>${book.bookName}</th> <th>${book.bookCounts}</th> <th>${book.detail}</th> <th><a href="${pageContext.request.contextPath}/Books/toUpdate?id=${book.bookID}">修改</a>|<a href="${pageContext.request.contextPath}/Books/DeleteBooks/${book.bookID}">刪除</a></th> </tr> </c:forEach> </tbody> </table> </body> </html>
3.新增書籍頁面（AddBooks.jsp）:
<%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>新增書籍</title> </head> <body> <form action="${pageContext.request.contextPath}/Books/AddBooks" method="post"> 書籍名字：<input type="text" name="bookName"/><br> 書籍數量：<input type="text" name="bookCounts"/><br> 書籍詳情：<input type="text" name="detail"/><br> <input type="submit" name="新增"/> </form> </body> </html>
4.修改書籍頁面（UpdateBooks.jsp）:
<%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>Title</title> </head> <body> <form action="${pageContext.request.contextPath}/Books/UpdateBooks" method="post"> <input type="hidden" name="bookID" value="${books.bookID}"> 書籍名字：<input name="bookName" type="text" value="${books.bookName}"><br> 書籍數量：<input name="bookCounts" type="text" value="${books.bookCounts}"><br> 書籍詳情：<input name="detail" type="text" value="${books.detail}"><br> <input type="submit" name="修改"> </form> </body> </html>
（18）開啟project structure，把包匯入
·初步建立專案後執行遇到的問題：
（1）applicationContext.xml的頭沒有寫全
（2）最後添加了Jackson的包沒有在project structure中新增
（3）空指標報錯異常檢查：web.xml配置的前段控制器繫結的配置檔案是否包含了所有配置、控制層呼叫的service的介面是new出來的還是spring的，new出來的是錯誤的。