SSM整合详细教学（上）

一、SSM整合

1. SSM整合配置

1.1 SSM整合流程

1. 创建工程
2. SSM整合
   • Spring
     • SpringConfig
   • MyBatis
     • MybatisConfig
     • JdbcConfig
     • jdbc.properties
   • SpringMVC
     • ServletConfig
     • SpringMvcConfig
3. 功能模块
   • 表与实体类
   • dao（接口+自动代理）
   • service（接口+实现类）
     • 业务层接口测试（整合JUnit）
   • controller
     • 表现层接口测试（PostMan）

1.2 SSM整合配置

1.2.1 创建工程，添加依赖和插件

<dependencies>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-webmvc</artifactId>
        <version>5.2.10.RELEASE</version>
    </dependency>

    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-jdbc</artifactId>
        <version>5.2.10.RELEASE</version>
    </dependency>

    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-test</artifactId>
        <version>5.2.10.RELEASE</version>
    </dependency>

    <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis</artifactId>
        <version>3.5.6</version>
    </dependency>

    <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis-spring</artifactId>
        <version>1.3.0</version>
    </dependency>

    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>5.1.47</version>
    </dependency>

    <dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>druid</artifactId>
        <version>1.1.16</version>
    </dependency>

    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.12</version>
        <scope>test</scope>
    </dependency>

    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>javax.servlet-api</artifactId>
        <version>3.1.0</version>
        <scope>provided</scope>
    </dependency>

    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-databind</artifactId>
        <version>2.9.0</version>
    </dependency>
</dependencies>

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.tomcat.maven</groupId>
            <artifactId>tomcat7-maven-plugin</artifactId>
            <version>2.1</version>
            <configuration>
                <port>80</port>
                <path>/</path>
            </configuration>
        </plugin>
    </plugins>
</build>

1.2.2 Spring整合Mybatis

• 创建数据库和表

-- 创建ssm_db数据库
CREATE DATABASE IF NOT EXISTS ssm_db CHARACTER SET utf8;

-- 使用ssm_db数据库
USE ssm_db;

-- 创建tbl_book表
CREATE TABLE tbl_book(
    id INT PRIMARY KEY AUTO_INCREMENT, -- 图书编号
    TYPE VARCHAR(100), -- 图书类型
    NAME VARCHAR(100), -- 图书名称
    description VARCHAR(100) -- 图书描述
);
-- 添加初始化数据
INSERT INTO tbl_book VALUES(NULL,'计算机理论','Spring实战 第5版','Spring入门经典教材，深入理解Spring原理技术内幕');
INSERT INTO tbl_book VALUES(NULL,'计算机理论','Spring 5核心原理与30个类手写实战','十年沉淀之作,手写Spring精华思想');
INSERT INTO tbl_book VALUES(NULL,'计算机理论','Spring 5设计模式','深入Spring源码剖析,Spring源码蕴含的10大设计模式');
INSERT INTO tbl_book VALUES(NULL,'市场营销','直播就该这么做:主播高效沟通实战指南','李子柒、李佳琦、薇娅成长为网红的秘密都在书中');
INSERT INTO tbl_book VALUES(NULL,'市场营销','直播销讲实战一本通','和秋叶一起学系列网络营销书籍');
INSERT INTO tbl_book VALUES(NULL,'市场营销','直播带货:淘宝、天猫直播从新手到高手','一本教你如何玩转直播的书,10堂课轻松实现带货月入3W+');

• jdbc.properties属性文件

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/ssm_db
jdbc.username=root
jdbc.password=root

• JdbcConfig配置类

public class JdbcConfig {
    
    
    @Value("${jdbc.driver}")
    private String driver;
    @Value("${jdbc.url}")
    private String url;
    @Value("${jdbc.username}")
    private String username;
    @Value("${jdbc.password}")
    private String password;
	//配置连接池
    @Bean
    public DataSource dataSource(){
    
    
        DruidDataSource dataSource = new DruidDataSource();
        dataSource.setDriverClassName(driver);
        dataSource.setUrl(url);
        dataSource.setUsername(username);
        dataSource.setPassword(password);
        return   dataSource;
    }
	//Spring事务管理需要的平台事务管理器对象
    @Bean
    public PlatformTransactionManager transactionManager(DataSource dataSource){
    
    
        DataSourceTransactionManager ds = new DataSourceTransactionManager();
        ds.setDataSource(dataSource);
        return ds;
    }
}

• MybatisConfig配置类

public class MybatisConfig {
    
    

    @Bean
    public SqlSessionFactoryBean sqlSessionFactory(DataSource dataSource) {
    
    
        SqlSessionFactoryBean factoryBean = new SqlSessionFactoryBean();
        factoryBean.setDataSource(dataSource);
        // typeAliasesPackage属性的作用是，搜索指定包别名
        // 配置了以后xml文件中的resultType和parameterType就不需要指定全类名
        factoryBean.setTypeAliasesPackage("com.sun.domain");
        return factoryBean;
    }
    @Bean
    public MapperScannerConfigurer mapperScannerConfigurer() {
    
    
        MapperScannerConfigurer msc = new MapperScannerConfigurer();
        // setBasePackage用于设置Mapper接口所在的基本包名，是实现自动扫描的关键方法
        msc.setBasePackage("com.sun.dao");
        return msc;
    }
}

• SpringConfig配置类

@Configuration
@ComponentScan({
    
    "com.sun.service"})
@PropertySource("classpath:jdbc.properties")
@Import({
    
    JdbcConfig.class,MyBatisConfig.class})
@EnableTransactionManagement //开启Spring事务管理
public class SpringConfig {
    
    
}

1.2.3 Spring整合SpringMVC

• SpringMvcConfig配置类

@Configuration
@ComponentScan("com.sun.controller")
@EnableWebMvc
public class SpringMvcConfig {
    
    
}

• ServletConfig配置类，加载SpringMvcConfig和SpringConfig配置类

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

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

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

2. 功能模块开发

2.1 数据层开发(BookDao)

• Book实体类

public class Book {
    
    
    private Integer id;
    private String type;
    private String name;
    private String description;
    //自行添加getter、setter、toString()方法
}

• BookDao接口

public interface BookDao {
    
    

    @Insert("insert into tbl_book (type,name,description) values(#{type},#{name},#{description})")
    public int save(Book book);  //返回值表示影响的行数

    @Update("update tbl_book set type = #{type}, name = #{name}, description = #{description} where id = #{id}")
    public int update(Book book);

    @Delete("delete from tbl_book where id = #{id}")
    public int delete(Integer id);

    @Select("select * from tbl_book where id = #{id}")
    public Book getById(Integer id);

    @Select("select * from tbl_book")
    public List<Book> getAll();
}

2.2 业务层开发(BookService/BookServiceImpl)

• BookService接口

@Transactional //表示所有方法进行事务管理
public interface BookService {
    
    

    /**
     * 保存
     * @param book
     * @return
     */
    public boolean save(Book book);

    /**
     * 修改
     * @param book
     * @return
     */
    public boolean update(Book book);

    /**
     * 按id删除
     * @param id
     * @return
     */
    public boolean delete(Integer id);

    /**
     * 按id查询
     * @param id
     * @return
     */
    public Book getById(Integer id);

    /**
     * 查询全部
     * @return
     */
    public List<Book> getAll();
}

• BookServiceImpl实现类

@Service
public class BookServiceImpl implements BookService {
    
    
    @Autowired
    private BookDao bookDao;

    public boolean save(Book book) {
    
    
        bookDao.save(book);
        return true;
    }

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

    public boolean delete(Integer id) {
    
    
        bookDao.delete(id);
        return true;
    }

    public Book getById(Integer id) {
    
    
        return bookDao.getById(id);
    }

    public List<Book> getAll() {
    
    
        return bookDao.getAll();
    }
}

2.3 表现层开发(BookController)

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

    @Autowired
    private BookService bookService;

    @PostMapping
    public boolean save(@RequestBody Book book) {
    
    
        return bookService.save(book);
    }

    @PutMapping
    public boolean update(@RequestBody Book book) {
    
    
        return bookService.update(book);
    }

    @DeleteMapping("/{id}")
    public boolean delete(@PathVariable Integer id) {
    
    
        return bookService.delete(id);
    }

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

    @GetMapping
    public List<Book> getAll() {
    
    
        return bookService.getAll();
    }
}

3. 接口测试

3.1 Spring整合Junit测试业务层方法

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

    @Autowired
    private BookService bookService;

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

    @Test
    public void testGetAll(){
    
    
        List<Book> all = bookService.getAll();
        System.out.println(all);
    }
}

3.2 postman测试表现层接口

• 测试保存图书

这里就以保存图书为例，其他接口同样测试

二、表现层数据封装

目前我们表现层响应给客户端的数据有哪几种？

1. 表现层响应数据的问题

问题：我们表现层增删改方法返回true或者false表示是否成功，getById()方法返回一个json对象，getAll()方法返回一个json对象数组，这里就出现了三种格式的响应结果，极其不利于前端解析。

解决：我们需要统一响应结果的格式

2. 定义Result类封装响应结果

2.1 Result类封装响应结果

public class Result {
    
    
    //描述统一格式中的数据
    private Object data;
    //描述统一格式中的编码，用于区分操作，可以简化配置0或1表示成功失败
    private Integer code;
    //描述统一格式中的消息，可选属性
    private String msg;

    public Result() {
    
    
    }
    public Result(Integer code,Object data) {
    
    
        this.data = data;
        this.code = code;
    }
    public Result(Integer code, Object data, String msg) {
    
    
        this.data = data;
        this.code = code;
        this.msg = msg;
    }
     //添加getter、setter、toString()方法
}

注意事项：

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Result类中的字段并不是固定的，可以根据需要自行增减

2.2 Code类封装响应码

//状态码
public class Code {
    
    
    public static final Integer SAVE_OK = 20011;
    public static final Integer DELETE_OK = 20021;
    public static final Integer UPDATE_OK = 20031;
    public static final Integer GET_OK = 20041;

    public static final Integer SAVE_ERR = 20010;
    public static final Integer DELETE_ERR = 20020;
    public static final Integer UPDATE_ERR = 20030;
    public static final Integer GET_ERR = 20040;
}

注意事项：

Code类的常量设计也不是固定的，可以根据需要自行增减，例如将查询再进行细分为GET_OK，GET_ALL_OK，GET_PAGE_OK

3 表现层数据封装返回Result对象

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

    @Autowired
    private BookService bookService;

    @PostMapping
    public Result save(@RequestBody Book book) {
    
    
        boolean flag = bookService.save(book);
        return new Result(flag ? Code.SAVE_OK:Code.SAVE_ERR,flag);
    }

    @PutMapping
    public Result update(@RequestBody Book book) {
    
    
        boolean flag = bookService.update(book);
        return new Result(flag ? Code.UPDATE_OK:Code.UPDATE_ERR,flag);
    }

    @DeleteMapping("/{id}")
    public Result delete(@PathVariable Integer id) {
    
    
        boolean flag = bookService.delete(id);
        return new Result(flag ? Code.DELETE_OK:Code.DELETE_ERR,flag);
    }

    @GetMapping("/{id}")
    public Result getById(@PathVariable Integer id) {
    
    
        Book book = bookService.getById(id);
        Integer code = book != null ? Code.GET_OK : Code.GET_ERR;
        String msg = book != null ? "" : "数据查询失败，请重试！";
        return new Result(code,book,msg);
    }

    @GetMapping
    public Result getAll() {
    
    
        List<Book> bookList = bookService.getAll();
        Integer code = bookList != null ? Code.GET_OK : Code.GET_ERR;
        String msg = bookList != null ? "" : "数据查询失败，请重试！";
        return new Result(code,bookList,msg);
    }
}