SSM框架整合——基本增删改查业务的实现
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1、环境要求
- IDEA
- mysql 5.7
- Tomcat 9
- Maven 3.6
需要熟练掌握MySQL数据库,Spring,JavaWeb及Mybatis知识,基本的前端知识;
2、数据库环境
create database ssmbuild;
use ssmbuild;
drop table id exists `books`;
CREATE TABLE `books` (
`book_id` int(11) NOT NULL AUTO_INCREMENT COMMENT ‘书id‘,
`book_name` varchar(255) NOT NULL COMMENT ‘名书‘,
`book_counts` int(11) NOT NULL COMMENT ‘量数‘,
`detail` varchar(255) NOT NULL COMMENT ‘描述‘,
PRIMARY KEY (`book_id`)
) ENGINE=InnoDB AUTO_INCREMENT=7 DEFAULT CHARSET=utf8
3、基本环境搭建
1、新建maven项目,添加web支持
2、pom依赖导入
<!--依赖-->
<dependencies>
<!--junit-->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
</dependency>
<!--mysql驱动-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.47</version>
</dependency>
<!--数据库连接池-->
<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>3.5.5</version>
</dependency>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis-spring</artifactId>
<version>2.0.5</version>
</dependency>
<!--spring-->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>5.2.7.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>5.2.8.RELEASE</version>
</dependency>
</dependencies>
3、maven资源过滤问题
<!--资源过滤-->
<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>
4、建立基本的结构和框架配置
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核心配置文件-->
<configuration>
</configuration>
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
https://www.springframework.org/schema/beans/spring-beans.xsd">
</beans>
4、Mybatis层编写
1、数据库配置文件database.properties
driver=com.mysql.jdbc.Driver
# 如果使用的是MySQL 8.0+ 需要增加一个时区的配置 serverTimezone=UTC
url=jdbc:mysql://localhost:3306/ssmbuild?useSSL=true&useUnicode=true&characterEncoding=utf
username=root
password=123465
2、IDEA关联数据库
3、编写mybatis核心配置文件
<?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核心配置文件-->
<configuration>
<settings>
<!--开启自动驼峰命名规则,数据库带_字段名自动转换为驼峰命名,user_id -> userId -->
<setting name="mapUnderscoreToCamelCase" value="true"/>
</settings>
<!--批量命名别名,默认命名为的别名为类名小写-->
<typeAliases>
<package name="com.spong.pojo"/>
</typeAliases>
</configuration>
4、pojo下创建实体类
Books
(可选择)使用lombok插件生成有参、无参构造及get、set方法
@Data
@AllArgsConstructor
@NoArgsConstructor
public class Books {
private Integer bookId;
private String bookName;
private Integer bookCounts;
private String detail;
}
5、编写dao层
BookMapper接口
public interface BookMapper {
//新增一本书
int addBook(Books books);
//删除一本书
//@Param 作用是用于传递参数,从而可以与SQL中的的字段名相对应
int deleteBook(@Param("bookId") Integer id);
//修改一本书
int updateBook(Books books);
//查询一本书
Books queryBookById(@Param("bookId") Integer id);
//查询所有书
List<Books> queryAllBooks();
}
BookMapper.xml实现BookMapper接口
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.spong.dao.BookMapper">
<insert id="addBook" parameterType="Books">
insert into ssmbuild.books(book_name, book_counts, detail)
values (#{bookName},#{bookCounts},#{detail});
</insert>
<delete id="deleteBook" parameterType="Integer">
delete from ssmbuild.books
where book_id=#{bookId};
</delete>
<update id="updateBook" parameterType="Books">
update ssmbuild.books
set book_name=#{bookName},
book_counts=#{bookCounts},
detail=#{detail}
where book_id=#{bookId};
</update>
<select id="queryBookById" parameterType="Integer" resultType="Books">
select *
from ssmbuild.books
where book_id=#{bookId};
</select>
<select id="queryAllBooks" resultType="Books">
select * from ssmbuild.books;
</select>
</mapper>
每创建一个mapper就在mybatis核心配置文件中配置
<mappers>
<mapper class="com.spong.dao.BookMapper"/>
</mappers>
6、编写service层
service层调用dao层,使用组合
BookService
public interface BookService {
//新增一本书
int addBook(Books books);
//删除一本书
int deleteBook(Integer id);
//修改一本书
int updateBook(Books books);
//查询一本书
Books queryBookById(Integer id);
//查询所有书
List<Books> queryAllBooks();
}
BookServiceImpl
public class BookServiceImpl implements BookService {
//service层调用dao层 组合Dao
private BookMapper bookMapper;
public void setBookMapper(BookMapper bookMapper) {
this.bookMapper = bookMapper;
}
public int addBook(Books books) {
return bookMapper.addBook(books);
}
public int deleteBook(Integer id) {
return bookMapper.deleteBook(id);
}
public int updateBook(Books books) {
return bookMapper.updateBook(books);
}
public Books queryBookById(Integer id) {
return bookMapper.queryBookById(id);
}
public List<Books> queryAllBooks() {
return bookMapper.queryAllBooks();
}
}
5、Spring层编写
1、spring-dao.xml配置
-
Spring关联数据库配置文件
<!--1.关联数据库配置文件--> <context:property-placeholder location="classpath:database.properties"/>
-
连接池(这里使用c3p0)
<!--2.连接池: dbcp: 半自动化操作,不能自动连接 c3p0: 自动化操作(自动化加载配置文件,并且可以自动设置到对象中) druid: 处理的数据量规模较大,可以进行数据的实时查询展示,查询模式是交互式的 hikari: 速度快、轻量的连接池,相比于其他连接池性能提示 --> <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"> <property name="driverClass" value="${driver}"/> <property name="jdbcUrl" value="${url}"/> <property name="user" value="${username}"/> <property name="password" value="${password}"/> <!--c3p0连接池的一些私有属性--> <property name="maxPoolSize" value="30"/> <property name="minPoolSize" value="10"/> <!--关闭连接后不自动commit--> <property name="autoCommitOnClose" value="false"/> <!--获取连接超时时间--> <property name="checkoutTimeout" value="10000"/> <!--当获取连接失败重试次数--> <property name="acquireRetryAttempts" value="2"/> </bean>
-
注册SQLSessionFactory
<!--3.SQLSessionFactory--> <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"> <!--注入数据源--> <property name="dataSource" ref="dataSource"/> <!--绑定mybatis配置文件--> <property name="configLocation" value="classpath:mybatis-config.xml"/> </bean>
-
扫描dao包,动态注入到Spring容器中
<!--4.配置dao扫描包,动态实现dao接口注入到Spring容器中--> <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"> <!--注入sqlSessionFactory--> <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/> <!--要扫描的dao包--> <property name="basePackage" value="com.spong.dao"/> </bean>
2、Spring-service.xml配置(事务)
-
扫描service下的包,实现动态注入
<!--1.扫描service下的包,注入Spring容器 需要使用注解--> <context:component-scan base-package="com.spong.service"/>
-
也可以选择直接配置service实现类(1,2选一)
<!--2.将所有的业务类注入到Spring,可以通过配置或者注解--> <bean id="BookServiceImpl" class="com.spong.service.BookServiceImpl"> <property name="bookMapper" ref="bookMapper"/> </bean>
-
声明事务配置
<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"> <!--注入数据源--> <property name="dataSource" ref="dataSource"/> </bean>
-
AOP事务(根据需要添加)
6、SpringMVC层编写
1、web.xml配置
-
DispatcherServlet 配置
<!--DispatcherServlet--> <servlet> <servlet-name>dispatcherServlet</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <!--绑定spring配置文件,获得初始化参数--> <init-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:spring-mvc.xml</param-value> </init-param> </servlet> <servlet-mapping> <servlet-name>dispatcherServlet</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping>
-
Filter过滤器
<!--乱码过滤--> <filter> <filter-name>encodingFilter</filter-name> <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class> </filter> <filter-mapping> <filter-name>encodingFilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping>
注意这里的url-pattern需要 /* 即jsp页面也需要过滤
关于web.xml的url映射的小知识: < url-pattern>/</url-pattern> 会匹配到/login这样的路径型url,不会匹配到模式为*.jsp这样的后缀型url < url-pattern>/*</url-pattern> 会匹配所有url:路径型的和后缀型的url(包括/login,*.jsp,*.js和*.html等)
-
Session相关配置
<!--Session--> <session-config> <!--Session保存时间 15分钟--> <session-timeout>15</session-timeout> </session-config>
2、Spring-mvc.xml配置
<!--1.开启注解驱动-->
<mvc:annotation-driven/>
<!--2.开启静态资源过滤-->
<mvc:default-servlet-handler/>
<!--3.扫描包:controller-->
<context:component-scan base-package="com.spong.controller"/>
<!--4.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>
最后将所有配置文件在applicationContext.xml文件中整合:
<?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
https://www.springframework.org/schema/beans/spring-beans.xsd">
<import resource="classpath:spring-dao.xml"/>
<import resource="classpath:spring-service.xml"/>
<import resource="classpath:spring-mvc.xml"/>
</beans>
到此框架整合完毕,开始视图层和controller层的编写
7、Controller层及视图页面
1.BookController类编写 方法一:查询全部书籍
@Controller
@RequestMapping("/books")
public class BookController {
//Controller层调Service层
//Spring容器自动注入其中的bookService
@Autowired
private BookService bookService;
//查询全部书籍,并返回一个显示所有书籍的页面
@RequestMapping("/allBooks")
public String queryAllBooks(Model model){
List<Books> booksList = bookService.queryAllBooks();
model.addAttribute("booksList",booksList);
return "allBooks";
}
}
2、书籍列表页面:
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>新增书籍</title>
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap@3.3.7/dist/css/bootstrap.min.css" >
</head>
<body>
<div class="container">
<div class="row clearfix">
<div class="col-md-12 column">
<div class="page-header">
<h1>
<small>书籍列表————新增书籍</small>
</h1>
</div>
</div>
</div>
<form action="${pageContext.request.contextPath}/books/addBook" method="post">
<div class="form-group">
<label for="bookName">书籍名称</label>
<input type="text" name="bookName" class="form-control" id="bookName" required>
</div>
<div class="form-group">
<label for="bookCounts">书籍数量</label>
<input type="text" name="bookCounts" class="form-control" id="bookCounts" required>
</div>
<div class="form-group">
<label for="detail">书籍详情</label>
<input type="text" name="detail" class="form-control" id="detail" required>
</div>
<button type="submit" class="btn btn-default">添加</button>
</form>
</div>
</body>
</html>
3.方法二 添加书籍
//跳转到书籍添加页面
@RequestMapping("/toAddBook")
public String toAddBook(){
return "addBook";
}
//添加书籍
@RequestMapping("/addBook")
public String addBook(Books books){
System.out.println("addBook=>"+books);
bookService.addBook(books);
return "redirect:/books/allBooks"; //重定向到首页
}
4.新增书籍链接以及页面
跳转
<div class="col-md-4 column">
<a class="btn btn-primary" href="${pageContext.request.contextPath}/books/toAddBook">新增书籍</a>
</div>
页面
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>新增书籍</title>
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap@3.3.7/dist/css/bootstrap.min.css" >
</head>
<body>
<div class="container">
<div class="row clearfix">
<div class="col-md-12 column">
<div class="page-header">
<h1>
<small>书籍列表————新增书籍</small>
</h1>
</div>
</div>
</div>
<form action="${pageContext.request.contextPath}/books/addBook" method="post">
<div class="form-group">
<label for="bookName">书籍名称</label>
<input type="text" name="bookName" class="form-control" id="bookName" required>
</div>
<div class="form-group">
<label for="bookCounts">书籍数量</label>
<input type="text" name="bookCounts" class="form-control" id="bookCounts" required>
</div>
<div class="form-group">
<label for="detail">书籍详情</label>
<input type="text" name="detail" class="form-control" id="detail" required>
</div>
<button type="submit" class="btn btn-default">添加</button>
</form>
</div>
</body>
</html>
5、方法三 修改书籍
//跳转到修改页面
@RequestMapping("/toUpdateBook")
public String toUpdateBook(Integer id, Model model){
System.out.println(id);
Books books = bookService.queryBookById(id);
model.addAttribute("qBook",books);
return "updateBook";
}
//修改书籍
@RequestMapping("/updateBook")
public String updateBook(Books books){
System.out.println("updateBook=>"+books);
bookService.updateBook(books);
return "redirect:/books/allBooks";
}
6、链接以及修改书籍页面
<a href="${pageContext.request.contextPath}/books/toUpdateBook?id=${book.bookId}">修改</a>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>修改书籍</title>
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap@3.3.7/dist/css/bootstrap.min.css" >
</head>
<body>
<div class="container">
<div class="row clearfix">
<div class="col-md-12 column">
<div class="page-header">
<h1>
<small>书籍列表————修改书籍</small>
</h1>
</div>
</div>
</div>
<form action="${pageContext.request.contextPath}/books/updateBook" method="post">
<%--id通过hidden传递--%>
<input type="hidden" name="bookId" value="${qBook.bookId}">
<div class="form-group">
<label for="bookName">书籍名称</label>
<input type="text" name="bookName" class="form-control" id="bookName" value="${qBook.bookName}" required>
</div>
<div class="form-group">
<label for="bookCounts">书籍数量</label>
<input type="text" name="bookCounts" class="form-control" id="bookCounts" value="${qBook.bookCounts}" required>
</div>
<div class="form-group">
<label for="detail">书籍详情</label>
<input type="text" name="detail" class="form-control" id="detail" value="${qBook.detail}" required>
</div>
<button type="submit" class="btn btn-default">修改</button>
</form>
</div>
</body>
</html>
7、方法四 删除书籍
//删除书籍
@RequestMapping("/deleteBook")
public String deleteBook(Integer id){
System.out.println("deleteBookId=>"+id);
bookService.deleteBook(id);
return "redirect:/books/allBooks";
}
8、删除链接
<a href="${pageContext.request.contextPath}/books/deleteBook?id=${book.bookId}">删除</a>
8、最终框架结构如下
BookController:
@Controller
@RequestMapping("/books")
public class BookController {
//Controller层调Service层
@Autowired
private BookService bookService;
//books为空时 查询全部书籍,并返回一个显示所有书籍的页面
//books.bookName有值时,模糊查询
@RequestMapping("/allBooks")
public String queryAllBooks(Books books,Model model){
System.out.println(books);
List<Books> booksList = bookService.queryAllBooks(books);
model.addAttribute("booksList",booksList);
return "allBooks";
}
//跳转到书籍添加页面
@RequestMapping("/toAddBook")
public String toAddBook(){
return "addBook";
}
//添加书籍
@RequestMapping("/addBook")
public String addBook(Books books){
System.out.println("addBook=>"+books);
bookService.addBook(books);
return "redirect:/books/allBooks"; //重定向到首页
}
//跳转到修改页面
@RequestMapping("/toUpdateBook")
public String toUpdateBook(Integer id, Model model){
System.out.println(id);
Books books = bookService.queryBookById(id);
model.addAttribute("qBook",books);
return "updateBook";
}
//修改书籍
@RequestMapping("/updateBook")
public String updateBook(Books books){
System.out.println("updateBook=>"+books);
bookService.updateBook(books);
return "redirect:/books/allBooks";
}
//删除书籍
@RequestMapping("/deleteBook")
public String deleteBook(Integer id){
System.out.println("deleteBookId=>"+id);
bookService.deleteBook(id);
return "redirect:/books/allBooks";
}
}
allBook.jsp:
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>所有书籍记录</title>
<%--bootStrap界面美化--%>
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap@3.3.7/dist/css/bootstrap.min.css" >
</head>
<body>
<div class="container">
<div class="row clearfix">
<div class="col-md-12 column">
<div class="page-header">
<h1>
<small>书籍列表————显示所有书籍</small>
</h1>
</div>
</div>
</div>
<div class="row">
<div class="col-md-4 column">
<a class="btn btn-primary" href="${pageContext.request.contextPath}/books/toAddBook">新增书籍</a>
</div>
<div class="col-md-4 column" style="float:right">
<form action="${pageContext.request.contextPath}/books/allBooks" method="post" class="form-inline">
<input type="text" name="bookName" class="form-control" placeholder="请输入书籍名称">
<input type="submit" class="btn btn-primary" value="查询">
</form>
</div>
</div>
<div class="row clearfix">
<div class="col-md-12 column">
<table class="table table-hover table-striped">
<thead>
<tr>
<th>书籍编号</th>
<th>书籍名称</th>
<th>书籍数量</th>
<th>书籍详情</th>
<th>操作</th>
</tr>
</thead>
<%--书籍从数据库中查询出来,在list中遍历:foreach--%>
<tbody>
<c:forEach var="book" items="${booksList}">
<tr>
<td>${book.bookId}</td>
<td>${book.bookName}</td>
<td>${book.bookCounts}</td>
<td>${book.detail}</td>
<td>
<a href="${pageContext.request.contextPath}/books/toUpdateBook?id=${book.bookId}">修改</a>
|
<a href="${pageContext.request.contextPath}/books/deleteBook?id=${book.bookId}">删除</a>
</td>
</tr>
</c:forEach>
</tbody>
</table>
</div>
</div>
</div>
</body>
</html>
addBook.jsp:
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>新增书籍</title>
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap@3.3.7/dist/css/bootstrap.min.css" >
</head>
<body>
<div class="container">
<div class="row clearfix">
<div class="col-md-12 column">
<div class="page-header">
<h1>
<small>书籍列表————新增书籍</small>
</h1>
</div>
</div>
</div>
<form action="${pageContext.request.contextPath}/books/addBook" method="post">
<div class="form-group">
<label for="bookName">书籍名称</label>
<input type="text" name="bookName" class="form-control" id="bookName" required>
</div>
<div class="form-group">
<label for="bookCounts">书籍数量</label>
<input type="text" name="bookCounts" class="form-control" id="bookCounts" required>
</div>
<div class="form-group">
<label for="detail">书籍详情</label>
<input type="text" name="detail" class="form-control" id="detail" required>
</div>
<button type="submit" class="btn btn-default">添加</button>
</form>
</div>
</body>
</html>
updateBook.jsp:
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>修改书籍</title>
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap@3.3.7/dist/css/bootstrap.min.css" >
</head>
<body>
<div class="container">
<div class="row clearfix">
<div class="col-md-12 column">
<div class="page-header">
<h1>
<small>书籍列表————修改书籍</small>
</h1>
</div>
</div>
</div>
<form action="${pageContext.request.contextPath}/books/updateBook" method="post">
<%--id通过hidden传递--%>
<input type="hidden" name="bookId" value="${qBook.bookId}">
<div class="form-group">
<label for="bookName">书籍名称</label>
<input type="text" name="bookName" class="form-control" id="bookName" value="${qBook.bookName}" required>
</div>
<div class="form-group">
<label for="bookCounts">书籍数量</label>
<input type="text" name="bookCounts" class="form-control" id="bookCounts" value="${qBook.bookCounts}" required>
</div>
<div class="form-group">
<label for="detail">书籍详情</label>
<input type="text" name="detail" class="form-control" id="detail" value="${qBook.detail}" required>
</div>
<button type="submit" class="btn btn-default">修改</button>
</form>
</div>
</body>
</html>
界面演示:
9、小结
这里只实现了基本ssm框架的整合以及简单增删改查业务的实现
更加复杂的业务还等着我们去面临和解决
对于框架底层的学习还远远不够,学会多看底层代码,深入理解原理,对以后框架的优化会有极大帮助
可能出现的BUG处理:
为方便SQL语句bug的查询,可在mybatis配置setting开启日志
<!--开启日志-->
<setting name="logImpl" value="STDOUT_LOGGING"/>
1.在对数据库进行查询时出现异常
java.sql.SQLException: Access denied for user ‘Poison‘@‘localhost‘ (using password: YES)
经检查driver,url,username,password等内容都无错误
原来db.properties配置如下:
driver=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/ssmbuild?useSSL=true&useUnicode=true&characterEncoding=utf8
username=root
password=123456
网上查询后得知:配置数据库用户名username和Spring中默认的username字段名冲突,
<property name="username" value="${username}"/>
在这里${username}默认查询的是系统用户名,而不是db.properties中配置的username
于是为了防止重名,将db.properties中的变量名修改如下,问题解决
jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/ssmbuild?useSSL=true&useUnicode=true&characterEncoding=utf8
jdbc.username=root
jdbc.password=123456
2.新增记录后刷新页面显示乱码
原因:web.xml中Filter的没有初始化encoding参数utf-8
由于CharacterEncodingFilter类的encoding属性允许为空,所以没有提示,一定要注意。
public class CharacterEncodingFilter extends OncePerRequestFilter {
@Nullable
private String encoding;
修改web.xml中Filter配置
<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>
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