SSM整合

项目结构配置搭建

pom的依赖：

 <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>

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


    <!-- https://mvnrepository.com/artifact/org.springframework/spring-webmvc -->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-webmvc</artifactId>
      <version>5.3.18</version>
    </dependency>

    <!--    添加json数据转换相关坐标-->

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

    <!--   Spring 操作数据库的包-->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-jdbc</artifactId>
      <version>6.0.0</version>
    </dependency>
    <!--mybatis包-->
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis</artifactId>
      <version> 3.5.11</version>
    </dependency>
    <!--mybatis 与 Spring整合的包-->
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis-spring</artifactId>
      <version>2.0.7</version>
    </dependency>
    <!--    mysql包-->
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>8.0.30</version>
    </dependency>
<!--    spring 测试包  版本需要跟spring-mvc的一样-->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-test</artifactId>
      <version>5.3.18</version>
    </dependency>
    <!--德鲁伊依赖-->
    <dependency>
      <groupId>com.alibaba</groupId>
      <artifactId>druid</artifactId>
      <version>1.2.14</version>
    </dependency>
  </dependencies>

配置文件夹的各个配置文件：

SpringConfig:

@Configuration
@ComponentScan({"com.study.service"})
@PropertySource("classpath:jdbc.properties")

//一定要加classpath: 不然读取不到

@Import({JdbcConfig.class, MybatisConfig.class})
public class SpringConfig {

}

SpringMvcConfig

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

JdbcConfig

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;

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

MybatisConfig

public class MybatisConfig {

    @Bean
    public SqlSessionFactoryBean sqlSessionFactory(DataSource dataSource){
        SqlSessionFactoryBean factoryBean =new SqlSessionFactoryBean();
        factoryBean.setDataSource(dataSource);
        factoryBean.setTypeAliasesPackage("com.study.domain");
        return factoryBean;
    }


    @Bean
    public MapperScannerConfigurer mapperScannerConfigurer(){
        MapperScannerConfigurer msc =new MapperScannerConfigurer();
        msc.setBasePackage("com.study.dao");
        return msc;
    }
}

ServletConfig

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[]{"/"};
    }
}

dao层：

public interface BrandDao {
    @Insert("insert into tb_brand1 values (null,#{brandName},#{description},#{status})")
    public void save(Brand brand);

    @Update("update tb_brand1 set brand_name=#{brandName}, description=#{description}, status=#{status} where id=#{id}")
    public void update(Brand brand);

    @Delete("delete from tb_brand1 where id =#{id}")
    //用@Results可以嵌套多个@Result
    @Results({
            @Result(property="brandName",column="brand_name")
    })
    public void delete(Integer id);

    @Select("select * from tb_brand1 where id = #{id}")
    @Results({
            @Result(property="brandName",column="brand_name")
    })
    public Brand getById(Integer id);

    @Select("select * from tb_brand1")
    public List<Brand> getAll();


}

service接口：

public interface BrandService {
    public boolean save(Brand brand);

    public boolean update(Brand brand);

    public boolean delete(Integer id);

    public Brand getById(Integer id);

    public List<Brand> getAll();
}

seivice实现类：

@Service
public class BrandServiceImpl implements BrandService {

    @Autowired
    private BrandDao brandDao;  //这里自动装配会报错，我们在设置里把检查的报错换成警告就可以了


    public boolean save(Brand brand) {
        brandDao.save(brand);
        return true;
    }

    public boolean update(Brand brand) {
        brandDao.update(brand);
        return true;
    }

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

    public Brand getById(Integer id) {
        return brandDao.getById(id);
    }

    public List<Brand> getAll() {
        return brandDao.getAll();
    }
}

REST风格的controller类：

@RestController
@RequestMapping("/brands")
public class BrandController {
    @Autowired
    private BrandService brandService;

@PostMapping
    public boolean save(@RequestBody Brand brand) {
        brandService.save(brand);
        return true;
    }
@PutMapping
    public boolean update(@RequestBody Brand brand) {
        brandService.update(brand);
        return true;
    }
@DeleteMapping("/{id}")
    public boolean delete(@PathVariable Integer id) {
        brandService.delete(id);
        return true;
    }
@GetMapping("/{id}")
    public Brand getById(@PathVariable Integer id) {
        return brandService.getById(id);
    }
@GetMapping
    public List<Brand> getAll() {
        return brandService.getAll();
    }
}

测试

注意：测试的spring-test版本需要跟spring-webmvc版本一致，否则会报错

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

    @Autowired
    private BrandService brandService;

    @Test
    public void testGetById(){
        Brand brand = brandService.getById(1);
        System.out.println(brand);
    }

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

增删改查的内容，我们直接用tomcat运行然后postman进行调试就可以了

事务

1.首先在JdbcConfig里面编写事务管理的bean类

2.在SpringConfig加上 @EnableTransactionManagement //注解开发事务

3.在对应的接口上加上@Transactional

表现层数据封装

我们后台返回的类型有很多，这时候我们封装成一个Result类，这样就统一起来，并且方便跟前端交互，封装的时候要记得设置相应的构造方法 这样会更方便

 然后我们再封装一个Code类，使用静态常量定义各个状态，这样我们就能通过类名.常量名调用了

 

Controller把所有返回值都设置成Result的结果：

@RestController
@RequestMapping("/brands")
public class BrandController {
    @Autowired
    private BrandService brandService;

    @PostMapping
    public Result save(@RequestBody Brand brand) {
        boolean flag = brandService.save(brand);
        return new Result(flag ? Code.SAVE_OK:Code.SAVE_ERR,flag);
    }

    @PutMapping
    public Result update(@RequestBody Brand brand) {
        boolean flag = brandService.update(brand);
        return new Result(flag ? Code.UPDATE_OK:Code.UPDATE_ERR,flag);
    }

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

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

        return new Result(code,brand,msg);
    }

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

异常处理器

 异常出现的地方会很多，最好就是集中在表现层进行处理

SpringMVC就提供了异常处理器

我们在Controller包里新建一个异常处理器

 项目异常处理方案

 

我们创建一个exception包

然后在里面分别自定义各个种类的异常类BusinessException 跟 SystemException

继承RuntimeException，并加一个code变量，分别写上构造方法。如：

public class SystemException extends RuntimeException{
    private Integer code;


    public SystemException( Integer code,String message) {
        super(message);
        this.code = code;
    }

    public SystemException(String message,Throwable cause, Integer code) {
        super(message,cause);

        this.code = code;
    }

    public Integer getCode() {
        return code;
    }

    public void setCode(Integer code) {
        this.code = code;
    }
}

 

触发后我们修改之前在controller层写的ProjectExceptionAdvice，分别拦截各种异常并作出相应的处理

 

 前端页面放行

为了避免，前端的页面已经js css之类的被SpringMVC拦截，我们新建一个SpringMvcSupport类

然后在SpringMvcConfig中把对应的包位置扫进去，就可以了

@ComponentScan({"com.study.controller","com.study.config"})