SpringMVC整合SSM实现表现层数据封装详解

沫洺 2022-11-02 我要评论

SSM整合配置

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）

SSM整合配置

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>
    <dependency>
      <groupId>org.projectlombok</groupId>
      <artifactId>lombok</artifactId>
      <version>1.18.24</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>

Spring整合Mybatis

创建数据库和表

-- 创建db5数据库
CREATE DATABASE IF NOT EXISTS db5 CHARACTER SET utf8;
-- 使用db5数据库
USE db5;
-- 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,'图书类型一','图书名称一','图书描述一');
INSERT INTO tbl_book VALUES(NULL,'图书类型二','图书名称二','图书描述二');
INSERT INTO tbl_book VALUES(NULL,'图书类型三','图书名称三','图书描述三');
INSERT INTO tbl_book VALUES(NULL,'图书类型四','图书名称四','图书描述四');
INSERT INTO tbl_book VALUES(NULL,'图书类型五','图书名称五','图书描述五');
INSERT INTO tbl_book VALUES(NULL,'图书类型六','图书名称六','图书描述六');

jdbc.properties属性文件

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/db5
jdbc.username=root
jdbc.password=123456

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);
        factoryBean.setTypeAliasesPackage("com.moming.domain");
        return factoryBean;
    }
    @Bean
    public MapperScannerConfigurer mapperScannerConfigurer(){
        MapperScannerConfigurer msc = new MapperScannerConfigurer();
        msc.setBasePackage("com.moming.dao");
        return msc;
    }
}

SpringConfig配置类

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

Spring整合SpringMVC

SpringMvcConfig配置类

@Configuration
@ComponentScan("com.moming.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[]{"/"};
    }
    //乱码处理
    @Override
    protected Filter[] getServletFilters() {
        CharacterEncodingFilter filter = new CharacterEncodingFilter();
        filter.setEncoding("UTF-8");
        return new Filter[]{filter};
    }
}

功能模块开发

数据层开发(BookDao)

Book实体类

@Data
public class Book {
    private Integer id;
    private String type;
    private String name;
    private String description;
}

BookDao接口

public interface BookDao {
    //@Insert("insert into tbl_book values(null,#{type},#{name},#{description})")
    @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();
}

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);
    /**
     * 根据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();
    }
}

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();
    }
}

接口测试

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);
    }
}

postman测试表现层接口

测试保存图书

表现层数据封装(前后端通信协议)

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

定义Result类封装响应结果

controller/Result类封装响应结果

@Data
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;
    }
}

注意事项：Result类中的字段并不是固定的，可以根据需要自行增减

controller/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

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);
    }
}

Postman测试