前言
本篇记录Spring、SpringMVC、Mybatis,也就是SSM的整合,并且是基于注解方法的整合。
- Spring,业务层,负责依赖注入、AOP
- SpringMVC,表现层,负责请求和响应流转的流程、以及3层的注解
- MyBatis,持久层,负责数据之间的操作
整合顺序
- 先Spring
- 再整合SpringMVC
- 最后整合MyBatis
案例
简单图片管理系统的增删改查
环境准备
- 创建工程,并加入依赖
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.itheima</groupId>
<artifactId>day35-08-ssm-crud</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>war</packaging>
<properties>
<maven.compiler.source>8</maven.compiler.source>
<maven.compiler.target>8</maven.compiler.target>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.encoding>UTF-8</maven.compiler.encoding>
<spring.version>5.2.10.RELEASE</spring.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-test</artifactId>
<version>${spring.version}</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>8.0.27</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>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.16</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.9.0</version>
</dependency>
</dependencies>
</project>
- 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+');
- 创建表对应的实体类
//lombok的注解,可以给实体类生成set\get和重写toString()方法
@Data
//2.生成全参构造函数
@AllArgsConstructor
//3.生成无参构造函数
@NoArgsConstructor
public class Book {
private Integer id;
private String type;
private String name;
private String description;
}
- 统一返回结构实体类
@Data
public class Result<T> {
/**
* 业务操作的类型编码
*/
private Integer code;
/**
* 封装业务返回的数据
*/
private T data;
/**
* 业务失败的错误消息
*/
private String msg;
/**
* 处理返回成功结果
*/
public static Result<String> success(Integer code) {
return success(code, "success");
}
/**
* 处理返回成功结果
*/
public static <T> Result<T> success(Integer code, T data) {
Result<T> result = new Result<>();
result.setCode(code);
result.setData(data);
return result;
}
/**
* 处理返回成功结果
*/
public static <T> Result<T> error(Integer code, T data, String msg) {
Result<T> result = new Result<>();
result.setCode(code);
result.setData(data);
result.setMsg(msg);
return result;
}
}
- 创建数据库配置文件
jdbc.username=root
jdbc.password=root
jdbc.url=jdbc:mysql://localhost:3306/ssm_db?serverTimezone=Asia/Shanghai&characterEncoding=utf8&useUnicode=true&useSSL=false
jdbc.driverClassName=com.mysql.cj.jdbc.Driver
搭建配置类
- JDBC配置类
public class JdbcConfig {
@Value("${jdbc.driverClassName}")
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;
}
}
- Spring配置类
@Configuration
//排除Controller
@ComponentScan(value = "com.itheima",
excludeFilters = @ComponentScan.Filter(
type = FilterType.ANNOTATION,
classes = Controller.class
)
)
//加载外部配置文件jdbc.properties
@PropertySource("classpath:jdbc.properties")
//加载其他配置类JdbcConfig.class
@Import({JdbcConfig.class, MybatisConfig.class})
//开启事务注解扫描
@EnableTransactionManagement
public class SpringConfig {
}
- SpringMVC配置类
@Configuration
@ComponentScan("com.itheima.controller")
@EnableWebMvc //这个注解有很多功能,这里暂时使用里面json与java对象自动转换
public class SpringMvcConfig implements WebMvcConfigurer {
/**
* 配置视图解析器,配置视图前缀与后缀
*/
@Bean
public InternalResourceViewResolver internalResourceViewResolver() {
InternalResourceViewResolver viewResolver = new InternalResourceViewResolver();
//配置前缀
viewResolver.setPrefix("/pages/");
//配置后缀
viewResolver.setSuffix(".jsp");
return viewResolver;
}
@Override
public void addResourceHandlers(ResourceHandlerRegistry registry) {
//静态资源访问配置
registry.addResourceHandler("/pages/**").addResourceLocations("/pages/");
registry.addResourceHandler("/js/**").addResourceLocations("/js/");
registry.addResourceHandler("/css/**").addResourceLocations("/css/");
registry.addResourceHandler("/plugins/**").addResourceLocations("/plugins/");
}
}
- Servlet配置类
public class ServletConfig extends AbstractDispatcherServletInitializer {
@Override
protected WebApplicationContext createServletApplicationContext() {
AnnotationConfigWebApplicationContext ac = new AnnotationConfigWebApplicationContext();
ac.register(SpringMvcConfig.class);
return ac;
}
@Override
protected String[] getServletMappings() {
//“/”,可以拦截除了jsp以外所有的资源的请求,拦截这些请求的目的是交给SpringMvc去处理
return new String[]{"/"};
}
@Override
protected WebApplicationContext createRootApplicationContext() {
AnnotationConfigWebApplicationContext ac = new AnnotationConfigWebApplicationContext();
ac.register(SpringConfig.class);
return ac;
}
/**
* 配置SpringMvc框架提供的处理post请求中文乱码过滤器
*/
@Override
protected Filter[] getServletFilters() {
CharacterEncodingFilter characterEncodingFilter = new CharacterEncodingFilter();
characterEncodingFilter.setEncoding("utf-8");
return new Filter[]{characterEncodingFilter};
}
}
- MyBatis配置类
public class MybatisConfig {
@Bean
public SqlSessionFactoryBean sqlSessionFactoryBean(DataSource dataSource) {
SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();
sqlSessionFactoryBean.setTypeAliasesPackage("com.itheima.domain");
sqlSessionFactoryBean.setDataSource(dataSource);
Configuration configuration = new Configuration();
//设置整合mybatis驼峰命名映射
configuration.setMapUnderscoreToCamelCase(true);
//设置打印日志
configuration.setLogImpl(StdOutImpl.class);
sqlSessionFactoryBean.setConfiguration(configuration);
return sqlSessionFactoryBean;
}
@Bean
public MapperScannerConfigurer mapperScannerConfigurer() {
MapperScannerConfigurer mapperScannerConfigurer = new MapperScannerConfigurer();
//设置mybatis加载映射接口位置
mapperScannerConfigurer.setBasePackage("com.itheima.dao");
return mapperScannerConfigurer;
}
}
编写 MVC 3层代码
数据持久层(Dao)
- BookDao
Mapper.java类,增、改、查,使用注解实现
public interface BookDao {
/**
* 新增图书
*/
@Insert("insert into tbl_book values (NULL, #{type}, #{name}, #{description})")
void add(Book book);
/**
* 删除图书
*/
void delete(Integer id);
/**
* 更新图书
*/
@Update("update tbl_book set type = #{id}, name = #{name}, description = #{description} where id = #{id}")
void update(Book book);
/**
* 按Id查询图书
*/
@Select("select * from tbl_book where id = #{id}")
Book findById(Integer id);
/**
* 查询所有图书
*/
@Select("select * from tbl_book")
List<Book> findAll();
}
- BookDao.xml
Mapper接口的xml映射文件,delete方法使用xml实现
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<!--
namespace:配置对应的Mapper接口的全类名:包名 + 接口名
-->
<mapper namespace="com.itheima.dao.BookDao">
<!-- 删除图书 -->
<delete id="delete">
delete
from tbl_book
where id = #{id}
</delete>
</mapper>
业务层
- BookService
业务层接口
//开启事务管理
@Transactional
public interface BookService {
/**
* 新增图书
*/
void add(Book book);
/**
* 删除图书
*/
void delete(Integer id);
/**
* 更新图书
*/
void update(Book book);
/**
* 按Id查询图书
*/
Book findById(Integer id);
/**
* 查询所有图书
*/
List<Book> findAll();
}
- BookServiceImpl
业务层实现类
@Service
public class BookServiceImpl implements BookService {
@Autowired
private BookDao bookDao;
@Override
public void add(Book book) {
bookDao.add(book);
}
@Override
public void delete(Integer id) {
bookDao.delete(id);
}
@Override
public void update(Book book) {
bookDao.update(book);
}
@Override
public Book findById(Integer id) {
return bookDao.findById(id);
}
@Override
public List<Book> findAll() {
return bookDao.findAll();
}
}
Web层(控制器)
- BookController
控制器,通过restful
风格编写增删查改的接口
@RestController
@RequestMapping("/book")
public class BookController {
@Autowired
private BookService bookService;
/**
* 新增图书
*/
@PostMapping
public String add(@RequestBody Book book) {
bookService.add(book);
System.out.println("添加成功");
return "success";
}
/**
* 删除图书
*/
@DeleteMapping("/{id}")
public String delete(@PathVariable Integer id) {
bookService.delete(id);
System.out.println("删除成功");
return "success";
}
/**
* 更新图书
*/
@PutMapping
public String update(@RequestBody Book book) {
bookService.update(book);
System.out.println("更新成功");
return "success";
}
/**
* 按Id查询图书
*/
@GetMapping("/{id}")
public Book findById(@PathVariable Integer id) {
return bookService.findById(id);
}
/**
* 查询所有图书
*/
@GetMapping
public List<Book> findAll() {
return bookService.findAll();
}
}
全局异常处理
- Code(业务异常错误码-常量)
/**
* 业务状态码
* <p>
* 前四位代表不同的操作,最后一位代表成功或失败(1成功、0失败)
*/
public interface Code {
/**
* 新增成功
*/
Integer SAVE_OK = 20011;
/**
* 删除成功
*/
Integer DELETE_OK = 20021;
/**
* 更新成功
*/
Integer UPDATE_OK = 20031;
/**
* 查询成功
*/
Integer GET_OK = 20041;
Integer SAVE_ERR = 20010;
Integer DELETE_ERR = 20020;
Integer UPDATE_ERR = 20030;
Integer GET_ERR = 20040;
}
- BusinessException(业务异常)
/**
* 业务异常
*/
public class BusinessException extends RuntimeException {
private static final long serialVersionUID = 5408508596626762201L;
private int code;
public BusinessException(int code, String message) {
super(message);
this.code = code;
}
public int getCode() {
return code;
}
public void setCode(int code) {
this.code = code;
}
@Override
public String toString() {
return "BusinessException{" +
"code=" + code +
'}';
}
}
- SystemException(系统异常)
/**
* 系统异常
*/
public class SystemException extends RuntimeException {
private static final long serialVersionUID = 5408508596626762201L;
private int code;
public SystemException(int code, String message) {
super(message);
this.code = code;
}
public int getCode() {
return code;
}
public void setCode(int code) {
this.code = code;
}
@Override
public String toString() {
return "SystemException{" +
"code=" + code +
'}';
}
}
- ProjectExceptionAdvice(全局异常处理器)
/**
* 注解:@RestControllerAdvice:异步请求全局异常处理器,最后封装为统一结果为json输出
* 注解:@ControllerAdvice,同步请求全局异常处理器,最后封装为ModelAndView,跳转视图页面输出
*/
@RestControllerAdvice
public class ProjectExceptionAdvice {
/**
* 可以预计的用户非法异常
*/
@ExceptionHandler(BusinessException.class)
public Result<String> doBusinessException(BusinessException ex) {
return Result.error(ex.getCode(), null, ex.getMessage());
}
/**
* 无法规避的系统异常
*/
@ExceptionHandler(SystemException.class)
public Result<String> doSystemException(SystemException ex) {
//打印异常到控制台
ex.printStackTrace();
return Result.error(ex.getCode(), null, ex.getMessage());
}
/**
* 全局异常捕获(捕获表现层所有Controller抛出的异常)
*/
@ExceptionHandler(Exception.class)
public Result<String> doException(Exception ex) {
//打印异常到控制台
ex.printStackTrace();
return Result.error(666, null, "服务器忙,请稍后再试");
}
}
测试
- 在
PostMan
或其他工具,访问http://localhost:8080/book
的相关接口(注意不同的请求方法,对应不同的功能接口)