Spring+SpringMVC+JDBC实现登录
有一位程序员去相亲的时候，非常礼貌得说自己是一名程序员，并解释自己是做底层架构的，于是女方听到"底层"两个字，就一脸嫌弃：什么时候能够到中高级？
用久了框架，把原生都忘记了，本章从零开始，熟悉一遍JDBC实现增删改查
开发环境
jdk 1.8
Maven 3.6
Spring、SpringMVC 4.3.18
dbcp2
jsp
Idea
创建项目
创建项目时，我们选择传统的Maven项目结构
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创建项目时不要选择任何模板，直接点Next
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填写包名及项目名Next --> Finish
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在main文件夹下创建webapp --> WEB-INF --> web.xml (如下图)
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web.xml内容如下
xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://xmlns.jcp.org/xml/ns/javaee"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee
http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
id="WebApp_ID" version="3.1">
<display-name>Demo-JDBCdisplay-name>
<welcome-file-list>
<welcome-file>index.jspwelcome-file>
welcome-file-list>
web-app>
引入jar包，添加Spring、SpringMVC配置
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在pom.xml中添加需要用到的jar包
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>4.0.0modelVersion>
<groupId>com.waynegroupId>
<artifactId>Demo-JDBCartifactId>
<version>1.0-SNAPSHOTversion>
<packaging>warpackaging>
<properties>
<servlet-version>3.1.0servlet-version>
<mysql-version>5.1.38mysql-version>
<commons-dbcp2-version>2.1.1commons-dbcp2-version>
<dbutil-version>1.6dbutil-version>
<spring-version>4.3.18.RELEASEspring-version>
<jstl-version>1.2jstl-version>
properties>
<dependencies>
<dependency>
<groupId>javax.servletgroupId>
<artifactId>javax.servlet-apiartifactId>
<version>${servlet-version}version>
<scope>providedscope>
dependency>
<dependency>
<groupId>mysqlgroupId>
<artifactId>mysql-connector-javaartifactId>
<version>${mysql-version}version>
dependency>
<dependency>
<groupId>org.apache.commonsgroupId>
<artifactId>commons-dbcp2artifactId>
<version>${commons-dbcp2-version}version>
dependency>
<dependency>
<groupId>commons-dbutilsgroupId>
<artifactId>commons-dbutilsartifactId>
<version>${dbutil-version}version>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-webartifactId>
<version>${spring-version}version>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-webmvcartifactId>
<version>${spring-version}version>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-contextartifactId>
<version>${spring-version}version>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-testartifactId>
<version>${spring-version}version>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-txartifactId>
<version>${spring-version}version>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-jdbcartifactId>
<version>${spring-version}version>
dependency>
<dependency>
<groupId>javax.servletgroupId>
<artifactId>jstlartifactId>
<version>${jstl-version}version>
dependency>
dependencies>
<build>
<finalName>Demo-JDBCfinalName>
<plugins>
<plugin>
<groupId>org.apache.tomcat.mavengroupId>
<artifactId>tomcat7-maven-pluginartifactId>
<version>2.2version>
<configuration>
<port>80port>
<path>/path>
<uriEncoding>UTF-8uriEncoding>
configuration>
plugin>
<plugin>
<groupId>org.apache.maven.pluginsgroupId>
<artifactId>maven-compiler-pluginartifactId>
<version>3.1version>
<configuration>
<source>1.8source>
<target>1.8target>
<encoding>UTF-8encoding>
configuration>
plugin>
plugins>
build>
<repositories>
<repository>
<id>publicid>
<name>aliyun nexusname>
<url>http://maven.aliyun.com/nexus/content/groups/public/url>
<releases>
<enabled>trueenabled>
releases>
repository>
repositories>
<pluginRepositories>
<pluginRepository>
<id>publicid>
<name>aliyun nexusname>
<url>http://maven.aliyun.com/nexus/content/groups/public/url>
<releases>
<enabled>trueenabled>
releases>
<snapshots>
<enabled>falseenabled>
snapshots>
pluginRepository>
pluginRepositories>
project>
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在resources下创建spring.xml，并添加一下内容
<context:component-scan base-package="com.wayne">
<context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
context:component-scan>
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在resources下创建springmvc.xml，并添加一下内容
<context:component-scan base-package="com.wayne">
<context:include-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
context:component-scan>
<mvc:annotation-driven/>
<mvc:default-servlet-handler/>
<bean id="viewResolver" class="org.springframework.web.servlet.view.UrlBasedViewResolver">
<property name="viewClass" value="org.springframework.web.servlet.view.JstlView"/>
<property name="prefix" value="/WEB-INF/views/"/>
<property name="suffix" value=".jsp"/>
bean>
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此时项目结构如下
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配置监听器及中央控制器，在web.xml中添加如下内容
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListenerlistener-class>
listener>
<context-param>
<param-name>contextConfigLocationparam-name>
<param-value>classpath:spring.xmlparam-value>
context-param>
<filter>
<filter-name>encodingFilterfilter-name>
<filter-class>org.springframework.web.filter.CharacterEncodingFilterfilter-class>
<init-param>
<param-name>encodingparam-name>
<param-value>UTF-8param-value>
init-param>
<init-param>
<param-name>forceEncodingparam-name>
<param-value>trueparam-value>
init-param>
filter>
<filter-mapping>
<filter-name>encodingFilterfilter-name>
<url-pattern>/*url-pattern>
filter-mapping>
<servlet>
<servlet-name>springmvcservlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServletservlet-class>
<init-param>
<param-name>contextConfigLocationparam-name>
<param-value>classpath*:springmvc.xmlparam-value>
init-param>
<load-on-startup>1load-on-startup>
servlet>
<servlet-mapping>
<servlet-name>springmvcservlet-name>
<url-pattern>/url-pattern>
servlet-mapping>
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至此，项目基础配置完成，我们顺便将项目所用各包创建完成，稍后介绍各类所起作用，此时项目结构如下
配置数据库连接
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在resources下的config.properties中声明我们要访问的数据库
jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://127.0.0.1:3306/db_test
jdbc.username=你的数据库用户名
jdbc.password=你的数据库密码
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在utils包下的ConnectionManager中配置数据库连接池
package com.wayne.utils; import org.apache.commons.dbcp2.BasicDataSource; import javax.sql.DataSource; import java.io.IOException; import java.util.Properties; /** * 数据库连接池 * @author Wayne * @date 2019/5/24 */ public class ConnectionManager { private static BasicDataSource dataSource = new BasicDataSource(); private static String DRIVER; private static String URL; private static String USERNAME; private static String PASSWORD; static { try { // 加载config.properties中配置的数据库连接信息 Properties prop = new Properties(); prop.load(ConnectionManager.class.getClassLoader().getResourceAsStream("config.properties")); DRIVER = prop.getProperty("jdbc.driver"); URL = prop.getProperty("jdbc.url"); USERNAME = prop.getProperty("jdbc.username"); PASSWORD = prop.getProperty("jdbc.password"); } catch (IOException e) { e.printStackTrace(); } dataSource.setDriverClassName(DRIVER); dataSource.setUrl(URL); dataSource.setUsername(USERNAME); dataSource.setPassword(PASSWORD); // 配置数据库连接池参数 dataSource.setInitialSize(2); dataSource.setMaxIdle(5); dataSource.setMinIdle(1); dataSource.setMaxWaitMillis(5000); } public static DataSource getConection() { return dataSource; } }
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在utils下的DBHelp编写CRUD工具类
package com.wayne.utils; import com.wayne.exception.DataAccessException; import org.apache.commons.dbutils.QueryRunner; import org.apache.commons.dbutils.ResultSetHandler; import java.sql.SQLException; /** * CRUD工具类 * @author Wayne * @date 2019/5/24 */ public class DbHelp { // 从连接池中获得连接 private static QueryRunner runner = new QueryRunner(ConnectionManager.getConection()); /** * 新增 * @param sql 待执行的SQL * @param rsh 结果集处理方式 * @param params SQL中的参数 * @param结果的类的详情信息 * @throws DataAccessException SQL执行错误时抛出的异常 */ public staticT insert(String sql, ResultSetHandler rsh, Object...params) throws DataAccessException { T t = null; try { t = runner.insert(sql, rsh, params); } catch (SQLException e) { throw new DataAccessException("执行: " + sql + "异常"); } return t; } /** * @param sql 待执行的SQL * @param params 结果集处理方式 * @throws DataAccessException SQL执行错误时抛出的异常 */ public static void update(String sql, Object... params) throws DataAccessException { try { runner.update(sql, params); } catch (SQLException e) { throw new DataAccessException("执行: " + sql + "异常"); } } /** * @param sql 待执行的SQL * @param rsh 结果集处理方式 * @param params SQL中的参数 * @param 结果的类的详情信息 * @throws DataAccessException SQL执行错误时抛出的异常 */ public staticT query(String sql, ResultSetHandler rsh, Object... params) throws DataAccessException { T t = null; try { t = runner.query(sql, rsh, params); } catch (SQLException e) { throw new DataAccessException("执行: " + sql + "异常"); } return t; } }
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在exception包下自定义DataAccessException异常
package com.wayne.exception; /** * 自定义异常类，用于转化sql异常 * @author Wayne * @date 2019/5/24 */ public class DataAccessException extends RuntimeException { private static final long serialVersionUID = 1L; public DataAccessException() { } public DataAccessException(String message) { super(message); } public DataAccessException(Throwable th) { super(th); } public DataAccessException(String message, Throwable th) { super(message, th); } }
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至此，工具类配置完成，可以开始写页面和接口了，我们顺带将登录页一并创建，此时项目结构如下
业务代码
此时就可以开始写我们的登录流程了，文末会放出完整代码，此处就不再展示，只讲逻辑；
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因为我们在web.xml中配置了index.jsp为欢迎页，所以当我们访问localhost:(端口号)时，会自动跳转到我们的index.jsp；
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此种项目结构，WEB-INF包及其子包下的所有内容，是无法通过前端直接访问到的，所以我们在index.jsp做了一个向后台请求的动作，请求接口为/user/login.html,此接口通过请求转发，访问到login.jsp；
启动项目
因为我们在项目内部集成了tomcat7插件，所以在启动的时候我们不需要额外配置tomcat，只需要通过maven命令启动即可
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选择Edit Configurations...
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点击+，选择maven，在Command line输入 clean tomcat7:run，点击ok
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点击绿色符号，就可以启动项目了
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启动完成后，访问localhost，就可以看到我们的首页了
源码下载
[Spring+SpringMVC+JDBC源码下载]
效果展示
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