项目建好了,那我们来集成以下dao,dao我们使用mybatis框架,以及druid数据库连接池、oscache缓存,数据库使用mysql 64位。
在pom里加上
<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>
<parent>
<groupId>scc-module</groupId>
<artifactId>module-parent</artifactId>
<version>0.0.1-SNAPSHOT</version>
</parent>
<artifactId>module-dao</artifactId>
<name>module-dao</name>
<description>dao组件</description>
<dependencies>
<!-- 数据库驱动jar -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.31</version>
</dependency>
<!-- mybatis jar -->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.2.7</version>
</dependency>
<dependency>
<groupId>org.mybatis.caches</groupId>
<artifactId>mybatis-oscache</artifactId>
<version>1.0.1</version>
</dependency>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis-spring</artifactId>
<version>1.2.2</version>
</dependency>
</dependencies>
</project>
然后在src/main/resources下建立configuration.xml文件,
<?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>
<!--给实体类起一个别名 user -->
<typeAlias type="scc.entry.User" alias="User" />
<typeAlias type="scc.util.DruidDataSourceFactory" alias="DRUID" />
</typeAliases>
<environments default="derby">
<environment id="derby">
<transactionManager type="JDBC" />
<dataSource type="DRUID">
<property name="url" value="jdbc:mysql://localhost:3306/test" />
<property name="username" value="root" />
<property name="password" value="1234" />
</dataSource>
</environment>
</environments>
<mappers>
<!--userMapper.xml装载进来 同等于把“dao”的实现装载进来 -->
<mapper resource="scc/mapper/userMapper.xml" />
</mappers>
</configuration>
mybatis第三方数据库连接池注意要实现DataSourcrFactory,
package scc.util;
import java.util.Properties;
import javax.sql.DataSource;
import org.apache.ibatis.datasource.DataSourceFactory;
public class DruidDataSourceFactory implements DataSourceFactory{
private DataSource dataSource;
@Override
public void setProperties(Properties props) {
try {
this.dataSource = com.alibaba.druid.pool.DruidDataSourceFactory.createDataSource(props);
} catch (final RuntimeException e) {
throw e;
} catch (final Exception e) {
throw new RuntimeException("init datasource error", e);
}
}
@Override
public DataSource getDataSource() {
return this.dataSource;
}
}
接着建立实体,dao接口,xml文件
package scc.entry;
public class User {
private Integer id;
private String name;
private Integer age;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Integer getAge() {
return age;
}
public void setAge(Integer age) {
this.age = age;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public User() {
}
}
package scc.dao;
import scc.entry.User;
public interface UserMapper {
public User findById(String Id);
}
<?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">
<!--这块等于dao接口的实现 namespace必须和接口的类路径一样-->
<mapper namespace="scc.dao.UserMapper">
<!-- findById必须和接口中的方法名一样 返回一个User 就是刚才的别名 如果不弄别名要连类路径一起写 麻烦-->
<select id="findById" parameterType="HashMap" resultType="User">
select * from student where id=#{id}
</select>
</mapper>
最后写一个测试类
package test;
import java.io.IOException;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.Test;
import scc.dao.UserMapper;
import scc.entry.User;
public class MybatisTest {
@Test
public void testMybatis() throws IOException{
SqlSessionFactory sessionFactory= new SqlSessionFactoryBuilder().build(Resources.getResourceAsReader("configuration.xml"));
SqlSession sqlSession = sessionFactory.openSession();
UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
User user = userMapper.findById("1");
System.out.println(user.getName());
}
}
欧了