【SpringMVC】SpringMVC基础教程(6)

前言：

本文内容：Fastjson使用、ssm整合Mybatis层、ssm整合Spring层

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Fastjson使用

fastjson.jar是阿里巴巴开发的一款专门用于Java开发的包，可以方便的实现json对象与JavaBean对象的转换，实现JavaBean对象与json字符串的转换，实现json对象与json字符串的转换。

fastjson的pom.xml依赖

<dependency>
           <groupId>com.alibaba</groupId>
           <artifactId>fastjson</artifactId>
           <version>1.2.62</version>
       </dependency>

fastjson三个主要的类：

JSONObject代表json对象
- JSONObject实现了Map接口
- JSONObject对应的json对象，同构各种形式的get()方法可以获取json对象中的数据，也可以利用size(),isEmpty()等方法获取"键：值"对的个数和判断是否为空。本质是通过实现Map接口并调用接口中的方法完成的
JSONArray代表json对象数组
- 内部是List接口中的方法来完成操作的。
JSON代表JSONObject和JSONArray的转化
- JSON类源码分析与使用
- 观察这些方法，主要是实现json对象，json对象数组，javabean对象，json字符串之间的相互转化

简单测试

@RequestMapping("/j5")
    @ResponseBody // 加这个注解就不会走视图解析器，会直接返回一个字符串
    public String json5(){


        List<User> list = new ArrayList<>();

        User user1 = new User("小王1",18,"男");
        User user2 = new User("小王2",18,"女");
        User user3 = new User("小王3",18,"男");

        list.add(user1);
        list.add(user2);
        list.add(user3);

        String str = JSON.toJSONString(list);

        return str;
    }

运行结果

1	[{"age":18,"name":"小王1","sex":"男"},{"age":18,"name":"小王2","sex":"女"},{"age":18,"name":"小王3","sex":"男"}]

ssm整合：Mybatis层

环境要求

IDEA
MySQL 8.0.22
Tomcat 8.5
Maven 3.6

要求熟练掌握MySQL数据库，Spring，JavaWeb以及Mybatis，简单前端知识

数据库环境

创建书籍数据库

create database `ssmbuild`;

use `ssmbuild`

drop table if exists `books`;

create table `books`(
	`bookID` int(10) not null auto_increment comment '书本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,'从入门到板砖'),(2,'MySQL',10,'从入门到跑路'),(3,'Linux',6,'从入门到落网')

基本环境搭建

新建Maven项目ssmBuild

在pom引入依赖


<!--    引入依赖-->
    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.22</version>
        </dependency>
        <dependency>
            <groupId>com.mchange</groupId>
            <artifactId>c3p0</artifactId>
            <version>0.9.5.5</version>
        </dependency>
        <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>2.1</version>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>jstl</artifactId>
            <version>1.2</version>
        </dependency>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
            <version>2.0.2</version>
        </dependency>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.8</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>5.3.19</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>5.3.8</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.24</version>
        </dependency>
    </dependencies>

Maven静态资源导出

<!--    静态资源导出-->
    <build>
        <resources>
            <resource>
                <directory>src/main/resources</directory>
                <includes>
                    <include>**/*.properties</include>
                    <include>**/*.xml</include>
                </includes>
                <filtering>true</filtering>
            </resource>
            <resource>
                <directory>src/main/java</directory>
                <includes>
                    <include>**/*.properties</include>
                    <include>**/*.xml</include>
                </includes>
                <filtering>true</filtering>
            </resource>
        </resources>
    </build>

建立基本结构和配置框架

com.jokerdig.pojo
com.jokerdig.controller
com.jokerdig.mapper
com.jokerdig.service

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>

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>

在IDEA中连接ssmbuild数据库

编写database.properties

jdbc.driver=com.mysql.cj.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/ssmbuild?useSSL=true&serverTimezone=UTC
jdbc.username=root
jdbc.password=123456

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>
<!--    数据源配置 交给spring-->

<!--    别名-->
    <typeAliases>
        <package name="com.jokerdig.pojo"/>
    </typeAliases>

<!--    绑定配置文件-->
    <mappers>
        <mapper class="com.jokerdig.mapper.BookMapper"/>
    </mappers>

</configuration>

新建实体类Books.java

package com.jokerdig.pojo;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

/**
 * @author Joker大雄
 * @data 2022/6/11 - 15:50
 **/
@Data
@NoArgsConstructor
@AllArgsConstructor
public class Books {
    private int bookID;
    private String bookName;
    private int bookCounts;
    private String detail;
}

新建接口BookMapper.java

package com.jokerdig.mapper;

import com.jokerdig.pojo.Books;
import org.apache.ibatis.annotations.Param;

import java.util.List;

/**
 * @author Joker大雄
 * @data 2022/6/11 - 15:55
 **/
public interface BookMapper {
    // 增加书籍
    int addBook(Books books);
    // 删除书籍
    int deleteBook(@Param("bookId") int id);
    // 修改书籍
    int updateBook(Books books);
    // 查询单本书籍
    Books getBookById(@Param("bookId") int id);
    // 查询全部书籍
    List<Books> queryAllBooks();
}

新建BookMapper.xml

<?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.jokerdig.mapper.BookMapper">
<!--    增删改查-->
    <insert id="addBook" parameterType="Books">
        insert into books(bookName,bookCounts,detail) values(#{bookName},#{bookCounts},#{detail})
    </insert>

    <delete id="deleteBook" parameterType="int">
        delete from books where bookID=#{bookId}
    </delete>

    <update id="updateBook" parameterType="Books">
        update books set bookName=#{bookName},bookCounts=#{bookCounts},detail=#{detail} where bookID=#{bookID}
    </update>

    <select id="getBookById" parameterType="int" resultType="Books">
        select * from books where bookID=#{bookId}
    </select>

    <select id="queryAllBooks" resultType="Books">
        select * from books
    </select>
</mapper>

新建接口BookService.java

package com.jokerdig.service;

import com.jokerdig.pojo.Books;

import java.util.List;

/**
 * @author Joker大雄
 * @data 2022/6/11 - 16:12
 **/
public interface BookService {
    // 增加书籍
    int addBook(Books books);
    // 删除书籍
    int deleteBook(int id);
    // 修改书籍
    int updateBook(Books books);
    // 查询单本书籍
    Books getBookById(int id);
    // 查询全部书籍
    List<Books> queryAllBooks();
}

新建接口实现类BookServiceImpl.java

package com.jokerdig.service;

import com.jokerdig.mapper.BookMapper;
import com.jokerdig.pojo.Books;

import java.util.List;

/**
 * @author Joker大雄
 * @data 2022/6/11 - 16:13
 **/
public class BookServiceImpl implements BookService {

    // mapper set注入
    private BookMapper bookMapper;

    public void setBookMapper(BookMapper bookMapper) {
        this.bookMapper = bookMapper;
    }

    @Override
    public int addBook(Books books) {
        return bookMapper.addBook(books);
    }

    @Override
    public int deleteBook(int id) {
        return bookMapper.deleteBook(id);
    }

    @Override
    public int updateBook(Books books) {
        return bookMapper.updateBook(books);
    }

    @Override
    public Books getBookById(int id) {
        return bookMapper.getBookById(id);
    }

    @Override
    public List<Books> queryAllBooks() {
        return bookMapper.queryAllBooks();
    }
}

Mybatis层整合完毕

ssm整合：Spring层

新建spring-mapper.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: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 https://www.springframework.org/schema/context/spring-context.xsd">

<!--    关联数据库配置文件-->
    <context:property-placeholder location="classpath:database.properties"/>
<!--    连接池
    dbcp:半自动化操作 不能自动连接
    c3p0:自动化的加载配置文件
    druid hikari
-->
    <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连接池私有属性-->
        <property name="maxPoolSize" value="30"/>
        <property name="minPoolSize" value="10"/>
        <property name="autoCommitOnClose" value="false"/>
    </bean>
<!--    SqlSessionFactory-->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource"/>
<!--        绑定mybatis配置文件-->
        <property name="configLocation" value="classpath:mybatis-config.xml"/>
    </bean>

<!--    配置扫描包-->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<!--        注入sqlSessionFactory-->
        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/>
<!--        扫描包-->
        <property name="basePackage" value="com.jokerdig.mapper"/>
    </bean>
</beans>

新建spring-service.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: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 https://www.springframework.org/schema/context/spring-context.xsd">

<!--    整合service-->
<!--    扫描service下的包-->
    <context:component-scan base-package="com.jokerdig.service"/>
<!--    将所有业务类注入spring 可以通过配置或者注解实现-->
    <bean id="BookServiceImpl" class="com.jokerdig.service.BookServiceImpl">
        <property name="bookMapper" ref="bookMapper"/>
    </bean>
<!--    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>
</beans>

service层整合完毕