重新整理，MyBatis3之初步，实体的增加、修改、删除、查询
作者：互联网
一、环境
mybatis-3.2版本，jdk1.8版本，Oracle数据库
二、准备工作
1. 下载mybatis-3.2，需要引用其中的若干包
mybatis-3.2.0.jar
lib/asm-3.3.1.jar
lib/cglib-2.2.2.jar
lib/commons-logging-1.1.1.jar
lib/javassist-3.17.1-GA.jar
lib/log4j-1.2.17.jar
lib/slf4j-api-1.7.2.jar
lib/slf4j-log4j12-1.7.2.jar
2 项目的目录结构
com.clzhang.mybatis.mapper MemberUserMapper.java MyBatis的mapper处理类 com.clzhang.mybatis.entity MemberUserBean.java MyBatis的entity类 com.clzhang.test MyBatisTest1.java 测试类，最终应该是在service的package中调用mapper中的方法。 resources\config mybatis-config.xml MyBatis的配置文件 resources\com\clzhang\mybatis\mapper MemberUserMapper.xml MyBatis的mapper配置文件
3.假定数据库已经创建，表结构也已经创建，并且有测试数据
CREATE TABLE MEMBER_USER ( ID NUMBER NOT NULL PRIMARY KEY, NAME VARCHAR2(30), PERSONMOBILE VARCHAR2(20), ADDRESS VARCHAR2(255), AGE NUMBER); CREATE SEQUENCE SEQ_MEMBER_USER;
三、具体步骤
1. 创建entity类
package com.clzhang.mybatis.entity;
public class MemberUserBean {
private int id;
private String name;
private String personMobile;
private String address;
private int age;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPersonMobile() {
return personMobile;
}
public void setPersonMobile(String personMobile) {
this.personMobile = personMobile;
}
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
}
View Code
2. 创建mapper类
package com.clzhang.mybatis.mapper;
import java.util.*;
import com.clzhang.mybatis.entity.MemberUserBean;
public interface MemberUserMapper {
public void insertUser(MemberUserBean user);
public void updateUser(MemberUserBean user);
public void deleteUser(int id);
public MemberUserBean getUser(int id);
public HashMap getUserHashMap(int id);
public List getUsersByAge(int startAge, int endAge);
}
View Code
3. 创建mybatis-config.xml的配置文件，位置于resources/config目录
<?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>
<settings>
<setting name="cacheEnabled" value="false" />
<setting name="useGeneratedKeys" value="true" />
<setting name="defaultExecutorType" value="REUSE" />
</settings>
<typeAliases>
<typeAlias alias="MemberUser" type="com.clzhang.mybatis.entity.MemberUserBean"/>
</typeAliases>
<environments default="development">
<environment id="development">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<property name="driver" value="oracle.jdbc.driver.OracleDriver"/>
<property name="url" value="jdbc:oracle:thin:@127.0.0.1:1521:orcl"/>
<property name="username" value="mytest"/>
<property name="password" value="test001"/>
</dataSource>
</environment>
</environments>
<mappers>
<mapper resource="com/clzhang/mybatis/mapper/MemberUserMapper.xml" />
</mappers>
</configuration>
4. 创建MemberUserMapper.xml配置文件，位置于：resources\com\clzhang\mybatis\mapper\
<?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.clzhang.mybatis.mapper.MemberUserMapper">
<!--
默认情况下是没有开启缓存的，下条代码是开启二级缓存的，作用如下：
1.•映射语句文件中的所有 select 语句将会被缓存。
2.•映射语句文件中的所有 insert,update 和 delete 语句会刷新缓存。
3.•缓存会使用 Least Recently Used(LRU,最近最少使用的)算法来收回。
......
-->
<cache />
<!--以单个对象方式返回-->
<select id="getUser" resultType="MemberUser" parameterType="int">
select
ID,
NAME,
PERSONMOBILE,
ADDRESS,
AGE
FROM MEMBER_USER
WHERE ID = #{id}
</select>
<!--以HashMap方式返回单个实例，包含列名与值的映射-->
<select id="getUserHashMap" resultType="hashmap" parameterType="int">
select
ID,
NAME,
PERSONMOBILE,
ADDRESS,
AGE
FROM MEMBER_USER
WHERE ID = #{id}
</select>
<resultMap type="MemberUser" id="userAgeMap">
<id property="id" column="id"/>
<!--有需要做数据库到实体类名称转换的，可以写在这里-->
<!--
<result property="objname" column="dbname"/>
-->
</resultMap>
<!--以List方式返回多个结果-->
<!--参数名称目前不可以自行指定（无法与Mapper中保持一致），待查-->
<select id="getUsersByAge" resultMap="userAgeMap" parameterType="int">
<![CDATA[
select
ID,
NAME,
PERSONMOBILE,
ADDRESS,
AGE
FROM MEMBER_USER
WHERE AGE > #{param1} AND AGE < #{param2}
]]>
</select>
<!--Oracle的实现自增长主键的方式-->
<insert id="insertUser" parameterType="MemberUser">
<selectKey keyProperty="id" resultType="int" order="BEFORE">
select SEQ_MEMBER_USER.nextval from DUAL
</selectKey>
INSERT INTO MEMBER_USER (ID, NAME, PERSONMOBILE, ADDRESS, AGE)
VALUES(#{id}, #{name}, #{personMobile}, #{address}, #{age})
</insert>
<update id="updateUser" parameterType="MemberUser">
update MEMBER_USER set
NAME = #{name},
PERSONMOBILE = #{personMobile},
ADDRESS = #{address},
AGE = #{age}
where id = #{id}
</update>
<delete id="deleteUser" parameterType="int">
delete from MEMBER_USER where ID = #{id}
</delete>
</mapper>
5. 创建测试类
package com.clzhang.test;
import java.io.IOException;
import java.io.Reader;
import java.util.*;
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 com.clzhang.mybatis.mapper.MemberUserMapper;
import com.clzhang.mybatis.entity.MemberUserBean;
/**
* mybatis的测试类，真正的应用，应该在service包中调用。
* @author Administrator
*
*/
public class MyBatisTest1 {
private static final String MYBATIS_CONFIG_FILENAME = "config/mybatis-config.xml";
private static SqlSessionFactory sqlSessionFactory;
static {
Reader reader = null;
try {
reader = Resources.getResourceAsReader(MYBATIS_CONFIG_FILENAME);
} catch (IOException e) {
System.out.println(e.getMessage());
}
// 一旦你创建了 SqlSessionFactory 后,SqlSessionFactoryBuilder这个类就不需要存在了。
sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
}
/**
* SqlSessionFactory 应该在你的应用执行期间都存在。没有理由来处理或重新创建它。
* @return
*/
public static SqlSessionFactory getSqlSessionFactory() {
return sqlSessionFactory;
}
// @Test
public void testInert() {
// SqlSession 的实例不能被共享,也是线程不安全的。因此最佳的范围是请求或方法范围。
SqlSession sqlSession = getSqlSessionFactory().openSession();
try {
// 从技术上来说,当被请求时,任意映射器实例的最宽范围和 SqlSession 是相同的。最佳范围是方法范围。
MemberUserMapper mapper = sqlSession
.getMapper(MemberUserMapper.class);
MemberUserBean memberUser = new MemberUserBean();
// 因为ID为自增长字段，所以此处不需要设置
memberUser.setName("李勇");
memberUser.setPersonMobile("998877");
memberUser.setAddress("江苏某地方");
memberUser.setAge(38);
mapper.insertUser(memberUser);
sqlSession.commit();
// 查看新加的对象主键
System.out.println("新加对象的id：" + memberUser.getId());
} finally {
sqlSession.close();
}
}
// @Test
public void testUpdate() {
SqlSession sqlSession = getSqlSessionFactory().openSession();
try {
MemberUserMapper mapper = sqlSession
.getMapper(MemberUserMapper.class);
// 先查询，后更新
MemberUserBean memberUser = mapper.getUser(8);
memberUser.setName("赵五副本");
memberUser.setPersonMobile("12345");
memberUser.setAddress("天津上地某公司");
memberUser.setAge(29);
mapper.updateUser(memberUser);
sqlSession.commit();
} finally {
sqlSession.close();
}
}
// @Test
public void testDelete() {
SqlSession sqlSession = getSqlSessionFactory().openSession();
try {
MemberUserMapper mapper = sqlSession.getMapper(MemberUserMapper.class);
// 直接设置ID主键，然后删除
mapper.deleteUser(2);
sqlSession.commit();
} finally {
sqlSession.close();
}
}
// @Test
public void getUser() {
SqlSession sqlSession = getSqlSessionFactory().openSession();
try {
MemberUserMapper mapper = sqlSession
.getMapper(MemberUserMapper.class);
MemberUserBean memberUser = mapper.getUser(5);
System.out.println("name:" + memberUser.getName() + "\tmobile:"
+ memberUser.getPersonMobile() + "\taddress:" + memberUser.getAddress());
} finally {
sqlSession.close();
}
}
// @Test
public void getUserHashMap() {
SqlSession sqlSession = getSqlSessionFactory().openSession();
try {
MemberUserMapper mapper = sqlSession
.getMapper(MemberUserMapper.class);
HashMap<String, Object> hashMap = mapper.getUserHashMap(5);
for (Map.Entry<String, Object> entry : hashMap.entrySet()) {
String key = entry.getKey();
Object value = entry.getValue();
System.out.println(key + ":" + value);
}
} finally {
sqlSession.close();
}
}
@Test
public void getUserByAge() {
SqlSession sqlSession = getSqlSessionFactory().openSession();
try {
MemberUserMapper mapper = sqlSession
.getMapper(MemberUserMapper.class);
List<MemberUserBean> myList = mapper.getUsersByAge(20, 40);
for (MemberUserBean entry : myList) {
int key = entry.getId();
String value = entry.getAddress();
System.out.println(key + ":" + value);
}
} finally {
sqlSession.close();
}
}
}
四、单独测试各个模块
解除注释JUnit各单元，然后键盘输入：alt+shift+X，T，分别进行测试。
标签：MemberUserMapper,mapper,MyBatis3,memberUser,查询,重新整理,sqlSession,mybatis,public 来源： https://www.cnblogs.com/nayitian/p/14990087.html