MyBatis创建流程

1、数据库代码如下：

create database chapter3;


use chapter3;


create table t_role (
id int(12) auto_increment,
role_name varchar(60) not null,
note varchar(256) null,
primary key(id)
);


insert into t_role(role_name, note) values('role_name_1', 'note_1');

2、用到的包如下：

3、log4j.properties

log4j.rootLogger=DEBUG , stdout
log4j.logger.org.mybatis=DEBUG
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%5p %d %C: %m%n

4、Role.java

5、RoleMapper.java

public interface RoleMapper {
public int insertRole(Role role);
public int deleteRole(Long id);
public int updateRole(Role role);
public Role getRole(Long id);
public List<Role> findRoles(String roleName);
}

6、RoleMapper.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.learn.ssm.chapter3.mapper.RoleMapper">


<insert id="insertRole" parameterType="role">
insert into t_role(role_name, note) values(#{roleName}, #{note})
</insert>


<delete id="deleteRole" parameterType="long">
delete from t_role where id= #{id}
</delete>


<update id="updateRole" parameterType="role">
update t_role set role_name = #{roleName}, note = #{note} where id= #{id}
</update>


<select id="getRole" parameterType="long" resultType="role">
select id,
role_name as roleName, note from t_role where id = #{id}
</select>


<select id="findRoles" parameterType="string" resultType="role">
select id, role_name as roleName, note from t_role
where role_name like concat('%', #{roleName}, '%')
</select>
</mapper>

7、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">
<configuration>
  <typeAliases><!-- 别名 -->
      <typeAlias alias="role" type="com.learn.ssm.chapter3.pojo.Role"/>
  </typeAliases>
  <!-- 数据库环境 -->
  <environments default="development">
    <environment id="development">
      <transactionManager type="JDBC"/>
      <dataSource type="POOLED">
        <property name="driver" value="com.mysql.jdbc.Driver"/>
        <property name="url" value="jdbc:mysql://localhost:3300/chapter3"/>
        <property name="username" value="root"/>
        <property name="password" value="root"/>
      </dataSource>
    </environment>
  </environments>
  <!-- 映射文件 -->
  <mappers>
    <mapper resource="com/learn/ssm/chapter3/mapper/RoleMapper.xml"/>
    <mapper class="com.learn.ssm.chapter3.mapper.RoleMapper2"/> 
  </mappers>

</configuration>

8、SqlSessionFactory.java

public class SqlSessionFactoryUtils {


private final static Class<SqlSessionFactoryUtils> LOCK = SqlSessionFactoryUtils.class;


private static SqlSessionFactory sqlSessionFactory = null;


private SqlSessionFactoryUtils() {
}


public static SqlSessionFactory getSqlSessionFactory() {
synchronized (LOCK) {
if (sqlSessionFactory != null) {
return sqlSessionFactory;
}
String resource = "mybatis-config.xml";
InputStream inputStream;
try {
inputStream = Resources.getResourceAsStream(resource);
sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
} catch (IOException e) {
e.printStackTrace();
return null;
}
return sqlSessionFactory;
}
}


//代码生成SqlSessionFactory
public static SqlSessionFactory getSqlSessionFactory2() {
synchronized (LOCK) {
//数据库连接池信息
PooledDataSource dataSource = new PooledDataSource();
dataSource.setDriver("com.mysql.jdbc.Driver");
dataSource.setUsername("root");
dataSource.setPassword("123456");
dataSource.setUrl("jdbc:mysql://localhost:3306/chapter3");
dataSource.setDefaultAutoCommit(false);
//采用MyBatis的JDBC事务方式
TransactionFactory transactionFactory = new JdbcTransactionFactory();
Environment environment = new Environment("development", transactionFactory, dataSource);
//创建Configuration对象
Configuration configuration = new Configuration(environment);
//注册一个MyBatis上下文别名
configuration.getTypeAliasRegistry().registerAlias("role", Role.class);
//加入一个映射器
configuration.addMapper(RoleMapper.class);
configuration.addMapper(RoleMapper2.class);
//使用SqlSessionFactoryBuilder构建SqlSessionFactory
sqlSessionFactory = 
   new SqlSessionFactoryBuilder().build(configuration);
return sqlSessionFactory;
}
}


public static SqlSession openSqlSession() {
if (sqlSessionFactory == null) {
getSqlSessionFactory();
}
return sqlSessionFactory.openSession();
}
}

9、Chapter3Main.java

public class Chapter3Main {
public static void main(String[] args) {
testRoleMapper();
testRoleMapper2();

}


private static void testRoleMapper() {
Logger log = Logger.getLogger(Chapter3Main.class);
SqlSession sqlSession = null;
try {
sqlSession = SqlSessionFactoryUtils.openSqlSession();
RoleMapper roleMapper = sqlSession.getMapper(RoleMapper.class);
Role role = roleMapper.getRole(1L);
log.info(role.getRoleName());
} finally {
if (sqlSession != null) {
sqlSession.close();
}
}
}

//注解SQL测试
private static void testRoleMapper2() {
Logger log = Logger.getLogger(Chapter3Main.class);
SqlSession sqlSession = null;
try {
sqlSession = SqlSessionFactoryUtils.openSqlSession();
RoleMapper2 roleMapper2 = sqlSession.getMapper(RoleMapper2.class);
Role role = roleMapper2.getRole(1L);
log.info(role.getRoleName());
} finally {
if (sqlSession != null) {
sqlSession.close();
}
}
}

}

10、测试