SSM(Spring-Mybatis-SpringMVC)
文章目录
-
- 1. 介绍
-
- 1.1 概念介绍
- 2 SSM整合框架
- 3. SSM功能模块开发
- 4 测试
-
- 4.1 业务层接口测试
- 4.2 表现层接口测试
- 5.优化 -表现层数据封装
- 6.异常处理
1. 介绍
1.1 概念介绍
SSM项目是指
基于Spring+SpringMVC+MyBatis框架搭建的Java Web项目。
- Spring是负责
管理和组织项目的IOC容器和AOP功能- SpringMVC是一个轻量级的
MVC框架，用于处理Web请求和响应- MyBatis是一种
持久化框架，用于进行数据库操作的ORM框架。
学习笔记：
Spring：https://blog.csdn.net/meini32/article/details/132474555
SpringMVC：https://blog.csdn.net/meini32/article/details/132545058
Mybatis：https://blog.csdn.net/meini32/article/details/132068955
Mybatis商品增删改查案例：https://blog.csdn.net/meini32/article/details/132095237
2 SSM整合框架
关键内容
Spring
- SpringConfig
SpringMVC
- SpringMvcConfig
- ServletConfig
Mybatis
- MyBatisConfig
- JdbcConfig
- jdbc.properties
MyBatis
jdbc.properties
jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/db1
jdbc.username=root
jdbc.password=123456
package com.it.config;
import javax.sql.DataSource;
import com.alibaba.druid.pool.DruidDataSource;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
//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;
//数据源
@Bean
public DataSource dataSource(){
DruidDataSource druidDataSource = new DruidDataSource();
druidDataSource.setDriverClassName(driver);
druidDataSource.setUrl(url);
druidDataSource.setUsername(username);
druidDataSource.setPassword(password);
return druidDataSource;
}
}
-----------------------------------------------------
package com.it.config;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.mapper.MapperScannerConfigurer;
import org.springframework.context.annotation.Bean;
import javax.sql.DataSource;
//MyBatisConfig
public class MybatisConfig {
//创建和管理数据库会话
@Bean
public SqlSessionFactoryBean sqlSessionFactory(DataSource dataSource){
SqlSessionFactoryBean factoryBean = new SqlSessionFactoryBean();
factoryBean.setDataSource(dataSource);
factoryBean.setTypeAliasesPackage("com.it.domain");
return factoryBean;
}
@Bean
//创建并配置MapperScannerConfigurer对象
public MapperScannerConfigurer mapperScannerConfigurer(){
MapperScannerConfigurer mapperScannerConfigurer = new MapperScannerConfigurer();
mapperScannerConfigurer.setBasePackage("com.it.dao");
return mapperScannerConfigurer;
}
}
web容器配置类
SpringMVC
- SpringMvcConfig
- ServletConfig
//ServletConfig
@Configuration
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[]{"/"};
}
}
----------------------------------------------------------------------
//SpringMvcConfig
@Configuration
@ComponentScan("com.it.controller")
@EnableWebMvc
public class SpringMvcConfig {
}
Spring
- SpringConfig
//整合Spring应用程序，实现对组件和属性的管理和使用
@Configuration
@ComponentScan({"com.it.service"})
@PropertySource("jdbc.properties")
@Import({jdbcConfig.class, MybatisConfig.class})
public class SpringConfig {
}
3. SSM功能模块开发
内容
- 表与实体类；
- dao（接口+自动代理）
- service（接口+实现类）
- controller
添加相关依赖
<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/maven-v4_0_0.xsd">
<modelVersion>4.0.0modelVersion>
<groupId>org.examplegroupId>
<artifactId>spring-ssmartifactId>
<packaging>warpackaging>
<version>1.0-SNAPSHOTversion>
<dependencies>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-webmvcartifactId>
<version>5.2.9.RELEASEversion>
dependency>
<dependency>
<groupId>com.fasterxml.jackson.coregroupId>
<artifactId>jackson-databindartifactId>
<version>2.9.0version>
dependency>
<dependency>
<groupId>org.mybatisgroupId>
<artifactId>mybatisartifactId>
<version>3.5.5version>
dependency>
<dependency>
<groupId>org.mybatisgroupId>
<artifactId>mybatis-springartifactId>
<version>1.3.0version>
dependency>
<dependency>
<groupId>mysqlgroupId>
<artifactId>mysql-connector-javaartifactId>
<version>5.1.32version>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-jdbcartifactId>
<version>5.3.13version>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-testartifactId>
<version>5.3.13version>
dependency>
<dependency>
<groupId>com.alibabagroupId>
<artifactId>druidartifactId>
<version>1.2.6version>
dependency>
<dependency>
<groupId>org.projectlombokgroupId>
<artifactId>lombokartifactId>
<version>1.18.28version>
dependency>
<dependency>
<groupId>javax.servletgroupId>
<artifactId>javax.servlet-apiartifactId>
<version>3.1.0version>
<scope>providedscope>
dependency>
dependencies>
<build>
<plugins>
<plugin>
<groupId>org.apache.tomcat.mavengroupId>
<artifactId>tomcat7-maven-pluginartifactId>
<version>2.2version>
<configuration>
<port>81port>
<path>path>
configuration>
plugin>
plugins>
build>
project>
import lombok.Data;
@Data
public class User {
private int id;
private String username;
private String password;
}
------------------------------------------------------------------------
package com.it.dao;
import com.it.domain.User;
import org.apache.ibatis.annotations.Delete;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.annotations.Update;
import java.util.List;
//用户增删改查接口
public interface UserDao {
@Insert("INSERT INTO tb_user values (null,#{name},#{password}}})")
public void save(User user);
@Update("UPDATE tb_user set name=#{id},password=#{password} where id=#{id}}")
public void update(User user);
@Delete("DELETE from tb_user where id = #{id}}")
public void delete(Integer id);
@Select("SELECT * FROM tb_user")
public List<User> selectAll();
@Select("SELECT * FROM tb_user WHERE id=#{id}")
public User selectById(Integer id);
}
----------------------------------------------------------------------
package com.it.service;
import com.it.domain.User;
import org.apache.ibatis.annotations.Delete;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.annotations.Update;
import java.util.List;
public interface UserService {
/**
* 保存
* @param user
* @return
*/
public boolean save(User user);
/**
* 修改
* @param user
* @return
*/
public boolean update(User user);
/**
* 删除
* @param id
* @return
*/
public boolean delete(Integer id);
/**
* 查全部
* @return
*/
public List<User> selectAll();
/**
* 按id查找
* @param id
* @return
*/
public User selectById(Integer id);
}
---------------------------------------------------------------------------
package com.it.service.impl;
import com.it.dao.UserDao;
import com.it.domain.User;
import com.it.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.List;
@Service
public class UserServiceImpl implements UserService {
@Autowired //自动装配
private UserDao userDao;
public boolean save(User user) {
userDao.save(user);
return true;
}
public boolean update(User user) {
userDao.update(user);
return true;
}
public boolean delete(Integer id) {
userDao.delete(id);
return true;
}
public List<User> selectAll() {
return userDao.selectAll();
}
public User selectById(Integer id) {
return userDao.selectById(id);
}
}
------------------------------------------------------------------------
package com.it.controller;
import com.it.domain.User;
import com.it.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;
import java.util.List;
@RestController
@RequestMapping("/user")
public class UserController {
@Autowired
private UserService userService;
@PostMapping
public boolean save(@RequestBody User user) {
return userService.save(user);
}
@PutMapping
public boolean update(@RequestBody User user) {
return userService.update(user);
}
@DeleteMapping("/{id}")
public boolean delete(@PathVariable Integer id) {
System.out.println(userService.delete(id));
return userService.delete(id);
}
@GetMapping
public List<User> selectAll() {
System.out.println(userService.selectAll());
return userService.selectAll();
}
@GetMapping("/{id}")
public User selectById(@PathVariable Integer id) {
return userService.selectById(id);
}
}
4 测试
4.1 业务层接口测试
4.2 表现层接口测试
5.优化 -表现层数据封装
- 前端接受数据格式封装到code属性用于区分操作
- 将特殊消息封装到message（msg）属性中
public class Result{
private Object data;
private Integer code;
private String msg;
}
package com.it.controller;
public class Code {
//成功
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 PUT_OK = 20051;
//失败
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;
public static final Integer PUT_ERR = 20050;
}
----------------------------------------------------------------------------
package com.it.controller;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
@Data
public class Result {
private Object data;
private Integer code;
private String msg;
public Result(Integer code, String msg) {
this.code = code;
this.msg = msg;
}
public Result(Object data, Integer code) {
this.data = data;
this.code = code;
}
public Result(Object data, Integer code, String msg) {
this.data = data;
this.code = code;
this.msg = msg;
}
}
---------------------------------------------------------------------------
import java.util.List;
@RestController
@RequestMapping("/user")
public class UserController {
@Autowired
private UserService userService;
@PostMapping
public Result save(@RequestBody User user) {
boolean save = userService.save(user);
return new Result(save,save?Code.SAVE_OK:Code.SAVE_ERR);
}
6.异常处理
出现异常位置及原因
- 框架内部抛出异常：不合规使用
- 数据层抛出异常：外边服务器故障（超时访问）
- 业务层抛出异常：业务逻辑书写错误（遍历业务书写操作等）
- 表现层抛出异常：数据收集、校验等规则导致
- 工具类抛出异常：工具书写不严谨不健壮
项目异常分类
- 业务异常
- 原因：用户行为导致
- 解决：发送相应的信息传递给用户，提醒规范操作。
- 系统异常
- 原因：项目运行时可预计但无法避免的异常
- 解决：发送固定消息安抚用户；发送消息给处理人员；记录日志；
- 其他异常
- 原因：未预期的异常
- 解决：同上
解决：集中统一处理项目中出现的异常（异常处理器）
@RestControllerAdvice
作用：为Rest风格开发的控制器类做增强
.
@ExceptionHandler
作用：位于方法上方，设置指定异常处理方案，出现异常后终止原始控制器，转入当前方法执行。
package com.it.controller;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class ProjectExceptionAdvice {
@ExceptionHandler(Exception.class)
public Result doException(Exception e){
System.out.println("出现异常");
return new Result(500,"出错");
}
}
步骤
- 自定义项目系统级异常
- 自定义业务级异常；
- 自定义异常编码；
- 触发自定义异常（模拟异常操作）；
- 拦截异常并处理异常；
- 测试结果
package com.it.controller;
import lombok.Data;
//自定义项目级异常
@Data
public class SystemException extends RuntimeException{
private Integer code;
public SystemException(String message, Throwable cause, Integer code) {
super(message);
this.code = code;
}
}
package com.it.controller;
import lombok.Data;
//自定义项目业务级异常
@Data
public class BusinessException extends RuntimeException{
private Integer code;
public BusinessException(String message, Integer code) {
super(message);
this.code = code;
}
public BusinessException(String message, Throwable cause, Integer code) {
super(message,cause);
this.code = code;
}
}
//异常编码
public static final Integer SYSTEM_UNKNOW_ERROR = 50001;
public static final Integer SYSTEM_TIMEOUT_ERROR = 50002;
public static final Integer PROJECT_VALIDATE_ERROR = 60001;
public static final Integer PROJECT_BUSINESS_ERROR = 60002;
package com.it.service.impl;
import com.it.controller.BusinessException;
import com.it.controller.Code;
import com.it.dao.UserDao;
import com.it.domain.User;
import com.it.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.List;
@Service
public class UserServiceImpl implements UserService {
@Autowired //自动装配
private UserDao userDao;
//自定义异常
public User selectById(Integer id) {
if(id<0){
throw new BusinessException("请输入正确的id",Code.PROJECT_BUSINESS_ERROR);
}
return userDao.selectById(id);
}
}
package com.it.controller;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.bind.annotation.RestControllerAdvice;
//拦截并处理异常
@RestControllerAdvice
public class ProjectExceptionAdvice {
@ExceptionHandler(Exception.class)
public Result doException(Exception e){
System.out.println("出现异常");
return new Result(500,"出错");
}
@ExceptionHandler(BusinessException.class)
public Result doBussinessException(Exception e){
System.out.println("出现业务异常");
return new Result(501,null,"出错");
}
@ExceptionHandler(SystemException.class)
public Result doSystemException(Exception e){
System.out.println("出现系统异常");
return new Result(500,"出错");
}
}
测试结果
