该后端工程的创建、开发过程均使用Intellij IDEA进行
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打开Intellij IDEA创建新的project，使用Spring Initializr创建springboot框架项目，步骤如下；
创建springboot项目
填写Group和Artifact，其他默认
选择Web-Spring Web和SQL-Mybatis Framework、MySQL Driver
填写项目名称和项目存储路径，之后项目创建成功
注：必须开启maven的自动导入，即pom文件自动导入依赖库（在项目创建成功之后会在IDE右下方弹出提醒开启）
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完成mybatis相关的配置；
创建mybatis-config.xml配置mybatis相关属性，代码如下：
// mybatis-config.xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<!-- 配置文件的根元素 -->
<configuration>
<!--配置全局属性-->
<settings>
<!--使用jdbc的getGeneratedKeys获取数据库自增主键值-->
<setting name="useGeneratedKeys" value="true"/>
<!--使用列标签替换列别名 默认未true-->
<setting name="useColumnLabel" value="true" />
<!--开启驼峰式命名转换：Table{create_time} -> Entity{createTime}-->
<setting name="mapUnderscoreToCamelCase" value="true" />
</settings>
</configuration>
完成spring配置（数据库、端口、配置文件路径等）代码如下：
// application.properties
#1.项目启动的端口
server.port=8080
#2.数据库连接参数
#2.1jdbc驱动，示数据库厂商决定，这是mysql的驱动
jdbc.driver=com.mysql.cj.jdbc.Driver
#2.2数据库连接url，包括ip(127.0.0.1)、端口(3306)、数据库名(testdb)
jdbc.url=jdbc:mysql://127.0.0.1:3306/ssm?useUnicode=true&characterEncoding=utf-8&useSSL=false
#2.3数据库账号名
jdbc.username=root
#2.4数据库密码
jdbc.password=511359588
#3.Mybatis配置
#3.1 mybatis配置文件所在路径
mybatis_config_file=mybatis-config.xml
#3.2 mapper文件所在路径，这样写可匹配mapper目录下的所有mapper，包括其子目录下的
mapper_path=/mapper/**/**.xml
#3.3 entity所在包
entity_package=com.evenzhu.ssm.entity
完成src路径下文件夹和class文件的创建，涉及代码如下：
// DataSourceConfiguration
package com.evenzhu.ssm.config.dao;
import com.mchange.v2.c3p0.ComboPooledDataSource;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import java.beans.PropertyVetoException;
/**
* 数据库配置类
*/
@Configuration
public class DataSourceConfiguration {
@Value("${jdbc.driver}")
private String jdbcDriver;
@Value("${jdbc.url}")
private String jdbcUrl;
@Value("${jdbc.username}")
private String jdbcUsername;
@Value("${jdbc.password}")
private String jdbcPassword;
@Bean(name = "dataSouce")
public ComboPooledDataSource createDataSouce() throws PropertyVetoException {
ComboPooledDataSource dataSource = new ComboPooledDataSource();
dataSource.setDriverClass(jdbcDriver);
dataSource.setJdbcUrl(jdbcUrl);
dataSource.setUser(jdbcUsername);
dataSource.setPassword(jdbcPassword);
//关闭连接后不自动commit
dataSource.setAutoCommitOnClose(false);
return dataSource;
}
}
// SessionFactoryConfiguration
package com.evenzhu.ssm.config.dao;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import javax.sql.DataSource;
import java.io.IOException;
/**
* 数据库sqlSession配置类
*/
@Configuration
public class SessionFactoryConfiguration {
@Value("${mapper_path}")
private String mapperPath;
@Value("${mybatis_config_file}")
private String mybatisConfigFilePath;
@Autowired
private DataSource dataSouce;
@Value("${entity_package}")
private String entityPackage;
@Bean(name="sqlSessionFactory")
public SqlSessionFactoryBean createSqlSessionFactoryBean() throws IOException {
SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();
sqlSessionFactoryBean.setConfigLocation(new ClassPathResource(mybatisConfigFilePath));
PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
String packageSearchPath = PathMatchingResourcePatternResolver.CLASSPATH_ALL_URL_PREFIX+mapperPath;
sqlSessionFactoryBean.setMapperLocations(resolver.getResources(packageSearchPath));
sqlSessionFactoryBean.setDataSource(dataSouce);
sqlSessionFactoryBean.setTypeAliasesPackage(entityPackage);
return sqlSessionFactoryBean;
}
}
// TransactionManagementConfiguration
package com.evenzhu.ssm.config.service;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Configuration;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;
import org.springframework.transaction.PlatformTransactionManager;
import org.springframework.transaction.annotation.EnableTransactionManagement;
import org.springframework.transaction.annotation.TransactionManagementConfigurer;
import javax.sql.DataSource;
/**
* 事务配置类，不可缺少，尚未知具体作用
*/
@Configuration
@EnableTransactionManagement
public class TransactionManagementConfiguration implements TransactionManagementConfigurer{
@Autowired
private DataSource dataSource;
@Override
public PlatformTransactionManager annotationDrivenTransactionManager() {
return new DataSourceTransactionManager(dataSource);
}
}
// TestController
package com.evenzhu.ssm.controller;
import com.evenzhu.ssm.entity.TestEntity;
import com.evenzhu.ssm.service.TestService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;
@RestController
@RequestMapping("/demoproject/test")
public class TestController {
@Autowired
private TestService testService ;
@RequestMapping(value = "/get/{id}",method = RequestMethod.GET)
public TestEntity test(@PathVariable Integer id){
System.out.println("id:" + id);
return testService.getById(id);
}
}
3.运行项目会报错，那是因为项目缺少一些依赖，需要在pom中添加依赖；
在pom文件中添加第三方库的依赖，代码如下：
<dependencies>
...
<dependency>
<groupId>com.mchange</groupId>
<artifactId>c3p0</artifactId>
<version>0.9.5.2</version>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
</dependencies>
4.截止到目前已经完成了ssm项目的初步配置，接下来需要完成数据库操作相关的配置和代码；
创建以上文件夹和文件，涉及代码如下：
// TestDao.class
package com.evenzhu.ssm.dao;
import com.evenzhu.ssm.entity.TestEntity;
import org.apache.ibatis.annotations.Mapper;
@Mapper
public interface TestDao {
TestEntity getById(Integer id);
}
// TestEntity.class
package com.evenzhu.ssm.entity;
public class TestEntity {
protected Integer id ;
protected String magicId ;
protected String firstName ;
protected String lastName ;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getMagicId() {
return magicId;
}
public void setMagicId(String magicId) {
this.magicId = magicId;
}
public String getFirstName() {
return firstName;
}
public void setFirstName(String firstName) {
this.firstName = firstName;
}
public String getLastName() {
return lastName;
}
public void setLastName(String lastName) {
this.lastName = lastName;
}
}
// TestService.class
package com.evenzhu.ssm.service;
import com.evenzhu.ssm.dao.TestDao;
import com.evenzhu.ssm.entity.TestEntity;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
@Service
public class TestService {
@Autowired
private TestDao testDao ;
public TestEntity getById(Integer id){
return testDao.getById(id);
}
}
// TestDaoMapper.xml
<?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" >
<mapper namespace="com.evenzhu.ssm.dao.TestDao">
<!-- 根据主键查询-->
<select id="getById" resultType="com.evenzhu.ssm.entity.TestEntity" parameterType="java.lang.Integer" >
select *
from test
where id = #{id}
</select>
</mapper>
数据库及表的创建
注：数据库配置在application.properties中，表名及SQL配置在
src/main/resources/mapper/**.xml中，配置信息一定要与数据库实际配置保持一致
浏览器测试请求成功，完成
注：篇中涉及的包名com.evenzhu.ssm必须改为读者自己项目的包名
全篇完，如有问题请评论私聊，我会及时回复并更新文章；
