# SSM整合

# 思路整理

# 框架之间的关系

spring framework(以下简称 spring)与spring mvc一样,都是管理java bean的容器.spring负责管理持久层与业务层相关的bean,也就是为dao和service提供bean,而spring mvc是为表现层提供bean,也就是为controller提供bean.spring和spring mvc也是一个父子容器的关系,spring是spring mvc的父容器,因此spring mvc可以访问spring容器,而反之则不行.两者也是高度整合的.

mybatis是持久层的框架,与spring关系不大,也是整合工作中的重点

mybatis有一个致命缺点,配置实在太麻烦了...

<?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>
        <!-- 实体类别名 -->
        <package name="top.brightzm.domain"/>
    </typeAliases>

    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <!-- 数据源 -->
                <property name="driver" value="org.mariadb.jdbc.Driver"/>
                <property name="url" value="jdbc:mariadb://127.0.0.1:3306/spring_db"/>
                <property name="username" value="root"/>
                <property name="password" value="root"/>
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <!-- 映射文件位置 -->
        <package name="top.brightzm.dao"/>
    </mappers>
</configuration>

执行sql语句也麻烦...

// 1.加载mybatis核心配置文件
String resource = "mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
// 2.创建sqlsession对象
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
// 3.获取sqlSession对象
SqlSession sqlSession = sqlSessionFactory.openSession();
// 4.获取mapper代理对象
BookDao bookDao = sqlSession.getMapper(BookDao.class);
// 5.调用接口方法
List<Book> books = BookDao.selectAll();

不过有了spring就一切好说~

mybatis这些什么配置统一变成bean,让spring管理去

数据源

@Bean
public DataSource dataSource() {
    DruidDataSource dataSource = new DruidDataSource();
    dataSource.setDriverClassName(className);
    dataSource.setUrl(url);
    dataSource.setUsername(username);
    dataSource.setPassword(password);
    return dataSource;
}

sqlSessionFactory

@Bean
public SqlSessionFactoryBean sqlSessionFactoryBean(DataSource dataSource){
    SqlSessionFactoryBean sessionFactoryBean = new SqlSessionFactoryBean();
    // 设置数据源
    sessionFactoryBean.setDataSource(dataSource);
    // 设置实体类别名
    sessionFactoryBean.setTypeAliasesPackage("top.brightzm.domain");
    return sessionFactoryBean;
}

映射文件扫描

@Bean
public MapperScannerConfigurer mapperScannerConfigurer(){
    // 映射文件扫描
    MapperScannerConfigurer mapperScannerConfigurer = new MapperScannerConfigurer();
    mapperScannerConfigurer.setBasePackage("top.brightzm.dao");
    return mapperScannerConfigurer;
}

调用接口方法

@Autowired
private BookDao bookDao;
@Override
public List<Book> selectAll() {
    List<Book> books = bookDao.selectAll();
    return books;
}

# 具体流程

创建工程

废话...
添加依赖

也是废话...
编写web项目入口配置类

这个不是废话

编写web项目入口配置类,当tomcat启动时自动加载spring和spring mvc配置,启动spring和spring mvc容器
编写配置类
dao domain service controller.... 吧啦吧啦
测试!!!

# 开始整合

# 添加依赖

pom.xml 文件中

# 核心依赖

spring webmvc

<dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-webmvc</artifactId>
      <version>5.2.22.RELEASE</version>
</dependency>

spring webmvc含有的资源

spring 和 spring mvc的全包含的,所以只要导入spring-webmvc一个依赖

# servlet

<dependency>
      <groupId>javax.servlet</groupId>
      <artifactId>javax.servlet-api</artifactId>
      <version>4.0.1</version>
      <scope>provided</scope>
</dependency>

# json数据转换

<dependency>
      <groupId>com.fasterxml.jackson.core</groupId>
      <artifactId>jackson-databind</artifactId>
      <version>2.13.3</version>
</dependency>

# 数据源相关

spring jdbc

<dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-jdbc</artifactId>
      <version>5.2.22.RELEASE</version>
</dependency>

数据库连接驱动

<dependency>
      <groupId>org.mariadb.jdbc</groupId>
      <artifactId>mariadb-java-client</artifactId>
      <version>3.0.7</version>
</dependency>

druid数据库连接池

<dependency>
      <groupId>com.alibaba</groupId>
      <artifactId>druid</artifactId>
      <version>1.2.14</version>
</dependency>

# Mybatis 相关

mybatis

<dependency>
      <groupId>org.mariadb.jdbc</groupId>
      <artifactId>mariadb-java-client</artifactId>
      <version>3.0.7</version>
</dependency>

mybatis整合spring

<dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis-spring</artifactId>
      <version>2.0.6</version>
</dependency>

# 单元测试

spring test

<dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-test</artifactId>
      <version>5.2.22.RELEASE</version>
</dependency>

junit

<dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.13.2</version>
      <scope>test</scope>
</dependency>

# 编写配置类

config目录下

# web核心配置

ServletConfig,继承AbstractAnnotationConfigDispatcherServletInitializer类

Abstract^抽象^Annotation^注解^Config^配置^DispatcherServlet^前置控制器^Initializer^初始化^
看下百度百科对DispatcherServlet的解释吧

DispatcherServlet是前置控制器，配置在web.xml文件中的。拦截匹配的请求，Servlet拦截匹配规则要自己定义，把拦截下来的请求，依据相应的规则分发到目标Controller来处理，是配置spring MVC的第一步。 DispatcherServlet是前端控制器设计模式的实现，提供Spring Web MVC的集中访问点，而且负责职责的分派，而且与Spring IoC容器无缝集成，从而可以获得Spring的所有好处。

继承该类之后需重写三个方法

getRootConfigClasses 获取spring配置类
getServletConfigClasses 获取spring mvc配置类
getServletMappings 拦截请求

public class ServletConfig extends AbstractAnnotationConfigDispatcherServletInitializer {
    
    @Override
    protected Class<?>[] getRootConfigClasses() {
        return new Class[]{SpringConfig.class};
    }

    @Override
    protected Class<?>[] getServletConfigClasses() {
        return new Class[]{SpringmvcConfig.class};
    }

    @Override
    protected String[] getServletMappings() {
        return new String[]{"/"};
    }

}

# 数据源配置

jdbc.properties

jdbc.driverClassName=org.mariadb.jdbc.Driver
jdbc.url=jdbc:mariadb://localhost:3306/spring_db
jdbc.username=root
jdbc.password=root

JdbcConfig配置数据源bean,还有spring的事务管理

为变量赋值 @Value

public class JdbcConfig {

    @Value("${jdbc.driverClassName}")
    private String className;

    @Value("${jdbc.url}")
    private String url;

    @Value("${jdbc.username}")
    private String username;

    @Value("${jdbc.password}")
    private String password;

    @Bean
    public DataSource dataSource() {
        DruidDataSource dataSource = new DruidDataSource();
        dataSource.setDriverClassName(className);
        dataSource.setUrl(url);
        dataSource.setUsername(username);
        dataSource.setPassword(password);
        return dataSource;
    }

    @Bean
    public PlatformTransactionManager transactionManager(DataSource dataSource){
        DataSourceTransactionManager ds = new DataSourceTransactionManager();
        ds.setDataSource(dataSource);
        return ds;
    }

}

# Mybatis配置

MyBatisConfig配置sqlSession工厂类SqlSessionFactoryBean以及映射文件扫描mapperScannerConfigurer

public class MybatisConfig {

    @Bean
    public SqlSessionFactoryBean sqlSessionFactoryBean(DataSource dataSource){
        SqlSessionFactoryBean sessionFactoryBean = new SqlSessionFactoryBean();
        // 设置数据源
        sessionFactoryBean.setDataSource(dataSource);
        // 设置实体类别名
        sessionFactoryBean.setTypeAliasesPackage("top.brightzm.domain");
        return sessionFactoryBean;
    }

    @Bean
    public MapperScannerConfigurer mapperScannerConfigurer(){
        // 映射文件扫描
        MapperScannerConfigurer mapperScannerConfigurer = new MapperScannerConfigurer();
        mapperScannerConfigurer.setBasePackage("top.brightzm.dao");
        return mapperScannerConfigurer;
    }
    
}

# Spring和Spring MVC配置

SpringConfig没啥好说的,为service和dao提供bean容器

标识为配置类 @Configuration
扫描service所在的包 @ComponentScan
开启事务管理 @EnableTransactionManagement
读取配置文件jdbc.properties @PropertySource

引入配置类 @Import

@Configuration
@EnableTransactionManagement
@ComponentScan("top.brightzm.service")
@PropertySource("classpath:jdbc.properties")
@Import({JdbcConfig.class,MybatisConfig.class})
public class SpringConfig {

}

SpringmvcConfig也差不多

标识为配置类 @Configuration
扫描controller所在的包 @ComponentScan

开启SpringMVC注解支持 @EnableWebMvc

@Configuration
@ComponentScan("top.brightzm.controller")
@EnableWebMvc
public class SpringmvcConfig {
}

# 功能模块

# 持久层

domain目录下模型类Book

public class Book {
    private Integer id;
    private String type;
    private String name;
    private String description;
    
    Constructor Getter Setter .....
    
}

dao目录下映射接口BookDao

public interface BookDao {

    @Select("SELECT * FROM tbl_book")
    List<Book> selectAll();

    @Select("SELECT * FROM tbl_book WHERE id = #{id}")
    Book selectById(Integer id);

    @Insert("INSERT INTO tbl_book VALUES (NULL,#{type},#{name},#{description})")
    void add(Book book);

    @Update("UPDATE tbl_book SET type=#{type}, name=#{name}, description=#{description} WHERE id = #{id}")
    void update(Book book);

    @Delete("DELETE FROM tbl_book WHERE id = #{id} ")
    void del(Integer id);

}

# 业务层

service目录下核心业务接口 BookService 以及实现类 BookServiceImpl

事务管理 @Transactional

@Transactional 
public interface BookService {

    public List<Book> selectAll();

    public Book selectById(Integer id);

    public boolean add(Book book);

    public boolean update(Book book);

    public boolean del(Integer id);
}

@Service
public class BookServiceImpl implements BookService {

    @Autowired
    private BookDao bookDao;

    @Override
    public List<Book> selectAll() {
        List<Book> books = bookDao.selectAll();
        return books;
    }

    @Override
    public Book selectById(Integer id) {
        Book book = bookDao.selectById(id);
        return book;
    }

    @Override
    public boolean add(Book book) {
        bookDao.add(book);
        return true;
    }

    @Override
    public boolean update(Book book) {
        bookDao.update(book);
        return true;
    }

    @Override
    public boolean del(Integer id) {
        bookDao.del(id);
        return true;
    }
}

# 表现层

controller目录下控制器BookController

@RestController
@RequestMapping("/books")
public class BookController {

    @Autowired
    private BookService bookService;

    @GetMapping
    public List<Book> selectAll(){
        List<Book> books = bookService.selectAll();
        return books;
    }

    @GetMapping("/{id}")
    public Book selectById(@PathVariable Integer id){
        Book book = bookService.selectById(id);
        return book;
    }

    @PostMapping
    public void add(@RequestBody Book book){
        boolean flag = bookService.add(book);
    }

    @PutMapping
    public void update(@RequestBody Book book){
        boolean flag = bookService.update(book);
    }

    @DeleteMapping("/{id}")
    public void delete(@PathVariable Integer id){
        boolean flag = bookService.del(id);
    }

}

# 测试

测试类BookServiceTest

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = SpringConfig.class)
public class BookServiceTest {

    @Autowired
    private BookService bookService;

    @Test
    public void selectAll(){
        List<Book> books = bookService.selectAll();
        System.out.println(books);
    }

    @Test
    public void selectById(){
        Book book = bookService.selectById(1);
        System.out.println(book);
    }

}

有数据展示即可

完结撒花~~

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