mybatis的基础curd操作

准备工作
mybatis的jar包，当前为3.2.7
mysql的java驱动jar包
junit的jar包和junit依赖的hamcrest-core jar包
mysql数据库的建库建表

建表语句

CREATE TABLE `t_category` (
`id` INT(11) NOT NULL AUTO_INCREMENT,
`name` VARCHAR(20) DEFAULT NULL,
PRIMARY KEY (`id`)
)

项目结构

        完成后的项目结构如下图

                                    


         关于mybatis的一些概念，官方文档清晰明了http://mybatis.github.io/mybatis-3/zh/index.html

搭建mybatis开发环境

        新建java项目

        添加所需jar包，并添加到classpath中

        参照官方文档添加mybatis的配置文件，下面是此demo的mybatis配置文件

mabatis_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>
<properties resource="curd.properties"></properties>
<typeAliases>
<typeAlias alias="Category" type="mybatis.curd.model.Category" />
</typeAliases>
<environments default="development">
<environment id="development">
<transactionManager type="JDBC" />
<dataSource type="POOLED">
<property name="driver" value="${driver}" />
<property name="url" value="${url}" />
<property name="username" value="${username}" />
<property name="password" value="${password}" />
</dataSource>
</environment>
</environments>
<mappers>
<mapper resource="mybatis/curd/dao/sql/category.xml" />
</mappers>
</configuration>

curd.properties

driver=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/db_mybatis_test?Unicode=true&characterEncoding=UTF-8
username=root
password=

            简单的mybatis工具类封装，获取sqlSessionFactory

MybatisUtil.java

package mybatis.curd.util;

import java.io.IOException;
import java.io.InputStream;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

public class MybatisUtil {
private static SqlSessionFactory sqlSessionFactory = null;

static {
try {
String resource = "mybatis_config.xml";
InputStream is = Resources.getResourceAsStream(resource);
sqlSessionFactory = new SqlSessionFactoryBuilder().build(is);
} catch (IOException e) {
e.printStackTrace();
}
}

public static SqlSessionFactory getSqlSessionFactory() {
return sqlSessionFactory;
}
}

          定义实体bean

Category.java

package mybatis.curd.model;

/**
* POJO
*
* @author guxingke
* */
public class Category {
private Integer id;
private String name;

public Integer getId() {
return id;
}

public void setId(Integer id) {
this.id = id;
}

public String getName() {
return name;
}

public void setName(String name) {
this.name = name;
}

@Override
public String toString() {
return "Category [id=" + id + ", name=" + name + "]";
}
}

数据库操作接口

CategoryDao.java

package mybatis.curd.dao;

import java.util.List;

import mybatis.curd.model.Category;

/**
* 定义接口，与具体持久化操作无关
*
* @author guxingke
* */
public interface CategoryDao {
public Category getCategory(Integer id);

public void saveCategory(Category category);

public void updateCategory(Category category);

public void deleteCategory(Integer id);

public List<Category> selectAll();

public List<Category> fuzzyQuery(String name);
}

mybatis的持久化操作mapper映射文件

category.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="mybatis.curd.dao.CategoryDao">
<!-- 新增记录 -->
<insert id="saveCategory" parameterType="Category">
insert into
t_category(name) values(#{name})
</insert>
<!-- 查询单条记录 -->
<select id="getCategory" parameterType="int" resultType="Category">
select *
from t_category where id = #{id}
</select>
<!-- 修改记录 -->
<update id="updateCategory" parameterType="Category">
update t_category set
name = #{name} where id = #{id}
</update>
<!-- 查询所有记录，查询多条记录即返回结果是一个集合的时候，resultType不是集合类型，而是集合所包含的类型 -->
<select id="selectAll" resultType="Category">
select * from t_category
</select>
<!-- 模糊查询 -->
<select id="fuzzyQuery" resultType="Category" parameterType="java.lang.String">
select *
from t_category where name like "%"#{name}"%"
</select>
<!-- 删除记录 -->
<delete id="deleteCategory" parameterType="int">
delete from t_category
where
id = #{id}
</delete>
</mapper>

测试mybatis3推荐的持久化操作方式

CategoryDaoTest2.java

package mybatis.curd.dao;

import java.util.List;

import mybatis.curd.model.Category;
import mybatis.curd.util.MybatisUtil;

import org.apache.ibatis.session.SqlSession;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

/**
* 测试mybatis3推荐的方式
*
* @author guxingke
* */
public class CategoryDaoTest2 {

@Test
public void testGetCategory() {
category = categoryDao.getCategory(1);
System.out.println(category);
}

@Test
public void testSaveCategory() {
category.setName("demo");
categoryDao.saveCategory(category);
}

@Test
public void testUpdateCategory() {
category.setId(3);
category.setName("test update id=3");
categoryDao.updateCategory(category);
}

@Test
public void testDeleteCategory() {
categoryDao.deleteCategory(2);
}

@Test
public void testSelectAll() {
List<Category> categories = categoryDao.selectAll();
for (Category category : categories) {
System.out.println(category);
}
}

@Test
public void testFuzzyQuery() {
List<Category> categories = categoryDao.fuzzyQuery("test");
for (Category category : categories) {
System.out.println(category);
}
}

@Before
public void setUp() {
session = MybatisUtil.getSqlSessionFactory().openSession();
category = new Category();
categoryDao = session.getMapper(CategoryDao.class);
}

@After
public void tearDown() {
session.commit();
session.close();
}

SqlSession session = null;
Category category = null;
CategoryDao categoryDao = null;
}

测试mybatis3之前的持久化操作方式

CategoryDaoTest.java

package mybatis.curd.dao;

import java.util.List;

import mybatis.curd.model.Category;
import mybatis.curd.util.MybatisUtil;

import org.apache.ibatis.session.SqlSession;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

/**
* 测试mybatis3之前的操作方式
*
* @author guxingke
* */
public class CategoryDaoTest {

@Test
public void testGetCategory() {
category = session.selectOne(
"mybatis.curd.dao.CategoryDao.getCategory", 1);
System.out.println(category);
}

@Test
public void testSaveCategory() {
category.setName("curd");
session.insert("mybatis.curd.dao.CategoryDao.saveCategory", category);
}

@Test
public void testUpdateCategory() {
category.setName("update di =3");
category.setId(3);
session.update("mybatis.curd.dao.CategoryDao.updateCategory", category);
}

@Test
public void testDeleteCategory() {
session.delete("mybatis.curd.dao.CategoryDao.deleteCategory", 2);
}

@Test
public void testSelectAll() {
List<Category> categories = session
.selectList("mybatis.curd.dao.CategoryDao.selectAll");
for (Category category : categories) {
System.out.println(category);
}
}

@Test
public void testFuzzyQuery() {
List<Category> categories = session.selectList(
"mybatis.curd.dao.CategoryDao.fuzzyQuery", "y");
for (Category category : categories) {
System.out.println(category);
}
}

@Before
public void setUp() {
session = MybatisUtil.getSqlSessionFactory().openSession();
category = new Category();
}

@After
public void tearDown() {
session.commit();
session.close();
}

SqlSession session = null;
Category category = null;
}