SpringMVC整合MyBatis
本项目基于狂神说Java的B站系列课程，仅用于个人学习。
1、环境要求
开发工具：IDEA
jdk：1.8
MySQL8.0+
Tomcat 9
Maven3.6.3
2、创建数据库
设计数据表ssmbuild.books，插入三条测试数据
CREATE DATABASE `ssmbuild`;
USE `ssmbuild`;
DROP TABLE IF EXISTS `books`;
CREATE TABLE `books`
(
`bookID` INT(10) NOT NULL AUTO_INCREMENT COMMENT '书id',
`bookName` VARCHAR(100) NOT NULL COMMENT '书名',
`bookCounts` INT(11) NOT NULL COMMENT '数量',
`detail` VARCHAR(200) NOT NULL COMMENT '描述',
KEY `bookID` (`bookID`)
) ENGINE = INNODB
DEFAULT CHARSET = utf8;
INSERT INTO `books`(`bookID`, `bookName`, `bookCounts`, `detail`)
VALUES (1, 'Java', 1, '从入门到放弃'),
(2, 'MySQL', 10, '从删库到跑路'),
(3, 'Linux', 5, '从进门到进牢');
3、环境搭建
3.1、导包
<dependencies>
<!-- junit -->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.13.2</version>
<scope>test</scope>
</dependency>
<!-- mysql驱动 -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.28</version>
</dependency>
<!-- 连接池cp30 -->
<dependency>
<groupId>com.mchange</groupId>
<artifactId>c3p0</artifactId>
<version>0.9.5.5</version>
</dependency>
<!-- servlet相关 -->
<!--servlet依赖-->
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>4.0.1</version>
<scope>provided</scope>
</dependency>
<!--jsp依赖-->
<dependency>
<groupId>javax.servlet.jsp</groupId>
<artifactId>javax.servlet.jsp-api</artifactId>
<version>2.3.3</version>
<scope>provided</scope>
</dependency>
<!--jstl依赖-->
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>jstl</artifactId>
<version>1.2</version>
</dependency>
<!-- standard -->
<dependency>
<groupId>taglibs</groupId>
<artifactId>standard</artifactId>
<version>1.1.2</version>
</dependency>
<!-- mybatis -->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.5.6</version>
</dependency>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis-spring</artifactId>
<version>2.0.6</version>
</dependency>
<!-- lombok -->
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.24</version>
</dependency>
<!-- spring -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>5.3.24</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>5.3.23</version>
</dependency>
</dependencies>
3.2、maven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>
3.3、建立项目结构
常用的包
-
com.thomas.controller -
com.thomas.pojo -
com.thomas.dao -
com.thomas.service -
com.thomas.filter -
com.thomas.utils
3.4、ssm整合：mybatis层
mybatis层就是要将MVC中的Model整合，包括dao层和service层。
1. 配置
mybatis主要用来操作数据库，所以在mybatis层我们要完成数据库有关的操作。
创建配置文件
mybatis-config.xml、applicationContext.xml以及数据库配置文件database.properties
database.properties
jdbc.driver=com.mysql.cj.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/ssmbuild?useSSL=true&useUnicode=true&characterEncoding=utf8
jdbc.username=用户名
jdbc.password=密码
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>
<!-- 配置包扫描，为pojo中的实体类取别名 -->
<!-- 注册mapper文件 -->
</configuration>
application-context.xml
这个先放着，具体配置后面整合spring的时候再来看
2. 定义数据库相关操作
-
定义实体类 com.thomas.pojo.Books.java
package com.thomas.pojo;
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;
}
-
定义dao层接口 com.thomas.dao.BookMapper.java
注意：这里id参数与数据库中字段名不一致，所以使用@Param将id指定为bookId
package com.thomas.dao;
import com.thomas.pojo.Books;
import org.apache.ibatis.annotations.Param;
import java.util.List;
public interface BookMapper {
//增加一本书
int addBook(Books books);
//删除一本书
int deleteBookById(@Param("bookId") int id);
//更新一本书
int updateBook(Books books);
//根据ID查询书
Books queryBookById(@Param("bookId") int id);
//查询全部书
List<Books> queryAllBooks();
}
-
编写 com.thomas.dao.BookMapper.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.thomas.dao.BookMapper">
<insert id="addBook" parameterType="Books">
insert into ssmbuild.books(bookName, bookCounts, detail)
VALUE (#{bookName}, #{bookCounts}, #{detail})
</insert>
<delete id="deleteBookById" parameterType="int">
delete from ssmbuild.books where bookID = #{bookId}
</delete>
<update id="updateBook" parameterType="Books">
update ssmbuild.books set bookCounts = #{bookCounts},
bookName = #{bookName},
detail = #{detail}
where bookID = #{bookID}
</update>
<select id="queryBookById" resultType="Books">
select * from ssmbuild.books where bookID = #{bookId}
</select>
<select id="queryAllBooks" resultType="Books">
select * from ssmbuild.books
</select>
</mapper>
-
编写完xml文件后，一定要立刻将其注册到 mybatis-config.xml中
<?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>
<typeAliases>
<package name="com.thomas.pojo"/>
</typeAliases>
<mappers>
<mapper class="com.thomas.dao.BookMapper"/>
</mappers>
</configuration>
-
添加service接口 com.thomas.service.BookService.java，这里其实跟BookMapper.java接口差不多
package com.thomas.service;
import com.thomas.pojo.Books;
import java.util.List;
public interface BookService {
//增加一本书
int addBook(Books books);
//删除一本书
int deleteBookById(int id);
//更新一本书
int updateBook(Books books);
//根据ID查询书
Books queryBookById(int id);
//查询全部书
List<Books> queryAllBooks();
}
-
service层调用dao层，实现 BookService接口（静态代理模式）
com.thomas.service.BookServiceImpl.java
package com.thomas.service;
import com.thomas.dao.BookMapper;
import com.thomas.pojo.Books;
import java.util.List;
public class BookServiceImpl implements BookService {
//业务层调用dao层
private BookMapper bookMapper;
public void setBookMapper(BookMapper bookMapper) {
this.bookMapper = bookMapper;
}
@Override
public int addBook(Books books) {
return bookMapper.addBook(books);
}
@Override
public int deleteBookById(int id) {
return bookMapper.deleteBookById(id);
}
@Override
public int updateBook(Books books) {
return bookMapper.updateBook(books);
}
@Override
public Books queryBookById(int id) {
return bookMapper.queryBookById(id);
}
@Override
public List<Books> queryAllBooks() {
return bookMapper.queryAllBooks();
}
}
3.5、ssm整合：spring层
spring层的整合就是要将数据源、业务、事务整合，包括spring-dao.xml和spring-service.xml
-
spring-dao.xmlspring配置整合mybatis需要有以下几步：
-
关联数据库配置 -
连接池 -
SqlSessionFactory -
动态的将dao接口注入到spring容器中
具体配置如下：
<?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"
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">
<!-- 1.关联数据库配置文件 -->
<context:property-placeholder location="classpath:database.properties"/>
<!-- 2.创建连接池 -->
<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
<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的私有属性 -->
<!-- 连接池个数 -->
<property name="maxPoolSize" value="30"/>
<property name="minPoolSize" value="10"/>
<!-- 关闭连接后不自动提交事务 -->
<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>
<!-- 3.SqlSessionFactory -->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="dataSource"/>
<!-- 绑定配置文件 -->
<property name="configLocation" value="classpath:mybatis-config.xml"/>
</bean>
<!-- 配置dao接口扫描包，动态的实现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"/>
<!-- 扫描dao包 -->
<property name="basePackage" value="com.thomas.dao"/>
</bean>
</beans>
-
spring-service.xml整合service层
spring层整合service层主要是将service层的业务整合
-
扫描service包 -
将所有的业务类注入到spring容器中 -
声明式事务 -
aop事务织入
<?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"
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">
<!-- 1.扫描service下的包 -->
<context:component-scan base-package="com.thomas.service"/>
<!-- 2.将所有的业务类注入到spring -->
<bean id="BookServiceImpl" class="com.thomas.service.BookServiceImpl">
<property name="bookMapper" ref="bookMapper"/>
</bean>
<!-- 3.声明式事务 -->
<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<!-- 注入数据源 -->
<property name="dataSource" ref="dataSource"/>
</bean>
<!-- 4.aop事务支持 -->
</beans>
我们需要将spring-dao.xml、spring-service.xml以及applicationContext.xml整合到同一个上下文中。
3.6、ssm整合：springmvc层
-
开启注解驱动 -
静态资源过滤 -
包扫描 -
视图解析器
在/WEB-INF下新建目录jsp，用来存放jsp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:mvc="http://www.springframework.org/schema/mvc"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd">
<!-- 1.注解驱动 -->
<mvc:annotation-driven/>
<!-- 2.静态资源过滤 -->
<mvc:default-servlet-handler/>
<!-- 3.扫描包: controller -->
<context:component-scan base-package="com.thomas.controller"/>
<!-- 4.视图解析器 -->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver" id="internalResourceViewResolver">
<property name="prefix" value="/WEB-INF/jsp/"/>
<property name="suffix" value=".jsp"/>
</bean>
</beans>
3.7、整合spring
将所有配置导入到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"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd">
<import resource="spring-dao.xml"/>
<import resource="spring-service.xml"/>
<import resource="spring-mvc.xml"/>
</beans>
4、编写页面
配置文件，暂时结束！Controller 和 视图层编写
4.1、方法一：查询所有书籍
controller层：调用service层，完成查询
package com.thomas.controller;
import com.thomas.pojo.Books;
import com.thomas.service.BookService;
import com.thomas.service.BookServiceImpl;
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.RequestMapping;
import java.util.List;
@Controller
@RequestMapping("/book")
public class BookController {
// controller调用service层
@Autowired
@Qualifier("BookServiceImpl")
private BookService bookService = new BookServiceImpl();
// 查询全部书籍
@RequestMapping("/allBooks")
public String list(Model model) {
List<Books> books = bookService.queryAllBooks();
System.out.println(books);
model.addAttribute("books", books);
return "allBooks";
}
}
编写首页：index.jsp
<%--
Created by IntelliJ IDEA.
User: geekthomas
Date: 2023/3/21
Time: 21:06
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>书籍首页</title>
<style>
h3 {
width: 180px;
height: 38px;
margin: 100px auto;
line-height: 38px;
text-align: center;
border-radius: 4px;
background-color: darkseagreen;
}
a {
text-decoration: none;
color:grey;
}
</style>
</head>
<body>
<h3>
<a href="${pageContext.request.contextPath}/book/allBooks">点击访问书籍详情页</a>
</h3>
</body>
</html>
allBooks.jsp
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>书籍展示页面</title>
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<link href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.0-alpha1/dist/css/bootstrap.min.css" rel="stylesheet"/>
</head>
<body>
<div class="container" style="margin-top: 100px">
<div class="row justify-content-md-center">
<div class="col-md-auto">
<div class="page-header">
<h1>
<small>
书籍页面——显示所有书籍
</small>
</h1>
</div>
</div>
</div>
<div class="row justify-content-md-center" style="margin-top: 20px">
<div class="col-md-12">
<table class="table table-striped table-hover">
<thead>
<tr>
<td>ID</td>
<td>书名</td>
<td>库存</td>
<td>详情</td>
</tr>
</thead>
<tbody>
<c:forEach var="book" items="${books}">
<tr>
<td>${book.bookID}</td>
<td>${book.bookName}</td>
<td>${book.bookCounts}</td>
<td>${book.detail}</td>
</tr>
</c:forEach>
</tbody>
</table>
</div>
</div>
</div>
</body>
</html>
启动tomcat，报错500，这里跟我们之前的一个坑有关系。之前我们在web.xml中配置DispatcherServlet时，设置的spring文件路径为spring-mvc.xml，这实际上并没有将dao层和service层中的Bean注入，如下所示：
因此，我们需要将classpath改为classpath:applicationContext.xml
重新启动
首页如下图所示：
allBooks.jsp页面：
3.2、方法二： 增加书籍
功能说明：在详情页点击添加书籍按钮->跳转到添加书籍页面->填写书籍信息->重定向到详情页。
controller层
//跳转到addBook页面
@RequestMapping("/toAddBook")
public String toAddBook() {
return "addBook";
}
//实现增加书籍功能
@RequestMapping("/addBook")
public String addBook(Books books) {
bookService.addBook(books);
return "redirect:/book/allBooks";
}
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>书籍展示页面</title>
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<link href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.0-alpha1/dist/css/bootstrap.min.css" rel="stylesheet"/>
<style>
a {
text-decoration: none;
color: wheat;
}
</style>
</head>
<body>
<div class="container" style="margin-top: 100px">
...
<div class="row">
<div class="col-md-4">
<button class="btn btn-primary">
<a href="${pageContext.request.contextPath}/book/toAddBook">添加书籍</a></button>
</div>
</div>
...
</div>
</body>
</html>
addBook.jsp
<%--
Created by IntelliJ IDEA.
User: geekthomas
Date: 2023/3/22
Time: 22:11
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>添加书籍</title>
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<link href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.0-alpha1/dist/css/bootstrap.min.css" rel="stylesheet"/>
</head>
<body>
<div class="container" style="margin-top: 100px">
<div class="row justify-content-md-center">
<div class="col-md-auto">
<div class="page-header">
<h1>
<small>
添加书籍
</small>
</h1>
</div>
</div>
</div>
<div class="row justify-content-md-center">
<div class="col-md-4">
<div class="card ">
<div class="card-body">
<form action="${pageContext.request.contextPath}/book/addBook" method="post">
<div >
<label for="bkName" class="form-label">书名</label>
<input type="text" name="bookName" class="form-control" id="bkName" required>
</div>
<div >
<label for="bkCounts" class="form-label">库存</label>
<input type="text" name="bookCounts" class="form-control" id="bkCounts" required>
</div>
<div >
<label for="detail" class="form-label">详情</label>
<input type="text" name="detail" class="form-control" id="detail" required>
</div>
<div class="col-md-2" style="margin-top:10px">
<input type="submit" class="form-control" value="提交">
</div>
</form>
</div>
</div>
</div>
</div>
</div>
</body>
</html>
点击即可提交。
4.3、方法三：修改书籍
修改书籍与增加书籍思路一致，都是先跳转到页面，然后在页面实现功能。
controller层
//跳转到修改书籍页面，需要携带books
@RequestMapping("/toUpdateBook")
public String toUpdateBook(Model model, int id) {
Books books = bookService.queryBookById(id);
model.addAttribute("books", books);
return "updateBook";
}
//修改书籍
@RequestMapping("/updateBook")
public String updateBook(Model model, Books books) {
int i = bookService.updateBook(books);
if (i > 0) {
System.out.println("修改成功");
}
return "redirect:/book/allBooks";
}
allBooks.jsp
在书籍详情页面添加修改按钮，点击跳转到localhost:8080/book/updateBook页面
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>书籍展示页面</title>
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<link href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.0-alpha1/dist/css/bootstrap.min.css" rel="stylesheet"/>
<style>
a {
text-decoration: none;
color: wheat;
}
</style>
</head>
<body>
<div class="container" style="margin-top: 100px">
...
<div class="row justify-content-md-center" style="margin-top: 20px">
<div class="col-md-12">
<table class="table table-striped table-hover">
<thead>
<tr>
<th>ID</th>
<th>书名</th>
<th>库存</th>
<th>详情</th>
<th>操作</th>
</tr>
</thead>
<tbody>
<c:forEach var="book" items="${books}">
<tr>
...
<td>
<button class="btn btn-warning">
<a href="${pageContext.request.contextPath}/book/toUpdateBook?id=${book.bookID}">修改</a>
</button>
</td>
</tr>
</c:forEach>
</tbody>
</table>
</div>
</div>
</div>
</body>
</html>
updateBook.jsp
<%--
Created by IntelliJ IDEA.
User: geekthomas
Date: 2023/3/22
Time: 22:11
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>修改书籍</title>
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<link href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.0-alpha1/dist/css/bootstrap.min.css" rel="stylesheet"/>
</head>
<body>
<div class="container" style="margin-top: 100px">
<div class="row justify-content-md-center">
<div class="col-md-auto">
<div class="page-header">
<h1>
<small>
修改书籍
</small>
</h1>
</div>
</div>
</div>
<div class="row justify-content-md-center">
<div class="col-md-4">
<div class="card ">
<div class="card-body">
<form action="${pageContext.request.contextPath}/book/updateBook" method="post">
<input type="hidden" name="bookID" value="${books.bookID}">
<div>
<label for="bkName" class="form-label">书名</label>
<input type="text" name="bookName" class="form-control" id="bkName" value="${books.bookName}">
</div>
<div>
<label for="bkCounts" class="form-label">库存</label>
<input type="text" name="bookCounts" class="form-control" id="bkCounts" value="${books.bookCounts}">
</div>
<div>
<label for="detail" class="form-label">详情</label>
<input type="text" name="detail" class="form-control" id="detail" value="${books.detail}">
</div>
<div class="col-md-2" style="margin-top:10px">
<input type="submit" class="form-control" value="提交">
</div>
</form>
</div>
</div>
</div>
</div>
</div>
</body>
</html>
==这里有个大坑：我们更新书籍的sql其实是需要书籍ID的，如果不隐藏的传递书籍ID，那就无法完成更新==
4.4、方法四：删除书籍
最后删除书籍，这里我们加一个验证框，点击删除的时候弹窗是否确定删除。
controller层
@RequestMapping("/deleteBook")
public String deleteBook(int id) {
bookService.deleteBookById(id);
return "redirect:/book/allBooks";
}
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>书籍展示页面</title>
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<link href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.0-alpha1/dist/css/bootstrap.min.css" rel="stylesheet"/>
<link href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.0-alpha1/dist/js/bootstrap.bundle.min.js" rel="script">
<style>
a {
text-decoration: none;
color: wheat;
}
</style>
</head>
<body>
<div class="container" style="margin-top: 100px">
<div class="row justify-content-md-center">
...
<c:forEach var="book" items="${books}">
<tr>
<td>${book.bookID}</td>
<td>${book.bookName}</td>
<td>${book.bookCounts}</td>
<td>${book.detail}</td>
<td>
<button class="btn btn-warning">
<a href="${pageContext.request.contextPath}/book/toUpdateBook?id=${book.bookID}">修改</a>
</button>
<button class="btn btn-danger">
<a href="${pageContext.request.contextPath}/book/deleteBook?id=${book.bookID}" onclick="return confirmDelete()">删除</a>
</button>
</td>
</tr>
</c:forEach>
</tbody>
</table>
</div>
</div>
</div>
<script>
function confirmDelete() {
return confirm("确定要删除本书籍吗?");
}
</script>
</body>
</html>
点击确认，即完成删除功能。
4.5、方法五：根据书名查询书籍
要实现根据书名查询书籍，我们需要在前端输入书名，根据书名做模糊查询，如果能查询到书籍，那就返回符合书名条件的书籍；如果不能查询到书籍，那就返回全部书籍，并且在前端予以提示。
前端页面：
allBooks.jsp
...
<div class="row" style="margin-top: 20px">
<div class="col-md-4">
<button class="btn btn-primary">
<a href="${pageContext.request.contextPath}/book/toAddBook">添加书籍</a>
</button>
</div>
<div class="col-md-6 offset-md-2">
<form action="${pageContext.request.contextPath}/book/queryBooksByName" method="post">
<div class="col-md-8" style="display:flex; justify-content: flex-end;">
<div class="col-auto" style="margin-right:10px">
<input type="text" name="bookName" class="form-control" id="queryBookName"
placeholder="请输入你要查询的书名" value="${bookName}">
</div>
<div class="col-auto">
<input type="submit" value="查询" class="btn btn-primary">
</div>
</div>
</form>
<span style="margin-left: 150px"><small style="color: orangered">${error}</small></span>
</div>
</div>
...
</script>
</body>
</html>
根据书名进行查询的底层方法还没有实现，我们这里按照dao->service-controller的顺序从下往上进行开发
BookMapper.java
在接口类中增加方法
List<Books> queryBooksByName(String name);
BookMapper.xml
编写sql，实现模糊查询
<select id="queryBooksByName" parameterType="String" resultType="Books">
select * from ssmbuild.books where bookName like #{name};
</select>
BookService.java
service层增加方法
List<Books> queryBooksByName(String name);
BookServiceImpl.java
调用dao层，实现方法
@Override
public List<Books> queryBooksByName(String name) {
return bookMapper.queryBooksByName(name);
}
BookController.java
获取前端传递参数，调用service层，查询符合条件的书籍。这里因为需要实现模糊查询，所以需要传递到sql中的参数应该为%书名%。如果没有查询到书籍，那么就给allBooks.jsp页面传递一个error信息，并且返回所有的书籍，这样不至于给用户返回空值。
@RequestMapping("/queryBooksByName")
public String queryBookByName(Model model, String bookName) {
System.out.println("要查询的书籍:" + bookName);
List<Books> books = new ArrayList<>();
//删除空格
books = bookService.queryBooksByName("%" + bookName.trim() + "%");
if (books == null || books.size() == 0) {
books = bookService.queryAllBooks();
model.addAttribute("error", "未查询到该书籍");
}
System.out.println("books: " + books);
model.addAttribute("books", books);
model.addAttribute("bookName", bookName);
return "allBooks";
}
测试：
-
输入 p，能查询到书名中有p的所有书籍
-
输入一个不存在的书名，返回所有书籍并提示
查询功能OK！以上就是一个简单的整合ssm的项目。之后我们将继续学习Spring全家桶之SpringBoot
原文始发于微信公众号（多肉罗罗）：JavaWeb-SpringMVC
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