Mybatis+PostgreSQL+Maven的一些配置

一、看一下项目结构吧

二、POM文件的一些配置

<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>zhd.cn</groupId>
  <artifactId>Mybatis</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>jar</packaging>

  <name>Mybatis</name>
  <url>http://maven.apache.org</url>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  </properties>

  <dependencies>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.4.6</version>
        </dependency>
        <dependency>
              <groupId>junit</groupId>
              <artifactId>junit</artifactId>
              <version>3.8.1</version>
          <scope>test</scope>
        </dependency>
            <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.12</version>
        </dependency>
        <dependency>
            <groupId>org.postgresql</groupId>
            <artifactId>postgresql</artifactId>
             <version>9.3-1102-jdbc41</version>
        </dependency>
  </dependencies>
</project>

三、Mybatis_config.xml的简单配置

<?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>
        <typeAlias alias="studentPojo" type="zhd.cn.Mybatis.pojo.StudentPojo" />
        <!-- 使用自动扫描的形式来定义别名，在Role中使用@Alias("role")注解进行说明-->
        <!-- <package name="com.jCuckoo.chapter02.pojo"/> -->
    </typeAliases>
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC" />
            <dataSource type="POOLED">
                <property name="driver" value="org.postgresql.Driver" />
                <property name="url" value="jdbc:postgresql://localhost:5432/mydb" />
                <property name="username" value="postgres" />
                <property name="password" value="password" />
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <mapper resource="zhd/cn/Mybatis/mapper/StudentMapper.xml" />
    </mappers>
</configuration>

四、Pojo和Mapper的配置

StudentPojo

package zhd.cn.Mybatis.pojo;

public class StudentPojo {
    
    private Long id;
    private String name;
    private String sex;
    
    public Long getId() {
        return id;
    }
    public void setId(Long id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getSex() {
        return sex;
    }
    public void setSex(String sex) {
        this.sex = sex;
    }
}

StudentMapper

package zhd.cn.Mybatis.mapper;

import zhd.cn.Mybatis.pojo.StudentPojo;

public interface StudentMapper {
    public StudentPojo getStudentPojo(Long id);
    public int insertStudentPojo(StudentPojo studentPojo);
    public int deleteStudentPojo(Long id);
}

StudentMapper.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="zhd.cn.Mybatis.mapper.StudentMapper">
    <select id="getStudentPojo" parameterType="long" resultType="studentPojo">
        select * from student where id = #{id}
    </select>
    <insert id="insertStudentPojo" parameterType="studentPojo">
        insert into student values(#{id},#{name},#{sex})
    </insert>
    <delete id="deleteStudentPojo" parameterType="long">
        delete from student where id=#{id}
    </delete>
</mapper>

五、会话工厂工具类

package zhd.cn.Mybatis.utils;

import java.io.IOException;
import java.io.InputStream;
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.apache.log4j.Logger;
import org.apache.log4j.Priority;

public class SqlSessionFactoryUtils {
    
    private static SqlSessionFactory sqlSessionFactory = null;
    private static final Class CLASS_LOCK=SqlSessionFactoryUtils.class;
    
    private SqlSessionFactoryUtils() {
        
    }
    public static SqlSessionFactory initSqlSessionFactory() {
        String resource = "mybatis_config.xml";
        InputStream inputStream = null;
        try {
            inputStream=Resources.getResourceAsStream(resource);
        } catch (IOException e) {
            Logger.getLogger(SqlSessionFactoryUtils.class.getName()).log(Priority.DEBUG, null, e);
        }
        synchronized (CLASS_LOCK) {
            if(sqlSessionFactory==null) {
                sqlSessionFactory=new SqlSessionFactoryBuilder().build(inputStream);
            }
        }
        return sqlSessionFactory;
    }
    public static SqlSession openSqlSession() {
        if(sqlSessionFactory==null) {
             initSqlSessionFactory();
        }
        return sqlSessionFactory.openSession();
    }
}

六、测试类

package zhd.cn.Mybatis;

import org.apache.ibatis.session.SqlSession;

import zhd.cn.Mybatis.mapper.StudentMapper;
import zhd.cn.Mybatis.pojo.StudentPojo;
import zhd.cn.Mybatis.utils.SqlSessionFactoryUtils;

/**
 * Hello world!
 *
 */
public class App 
{
    public static void main( String[] args )
    {
        System.out.println( "Hello World!" );
        SqlSession sqlSession=null;
        sqlSession=SqlSessionFactoryUtils.openSqlSession();
        StudentMapper studentMapper=sqlSession.getMapper(StudentMapper.class);
        StudentPojo  studentPojo =studentMapper.getStudentPojo((long) 1);
        System.out.println(studentPojo.getId()+" "+studentPojo.getName());
        studentPojo.setId((long) 2);
        studentMapper.insertStudentPojo(studentPojo);
        sqlSession.commit();       
    }
}