spring-mybatis-data-common-2.0新增分表机制,在1.0基础上做了部分调整.
基于机架展示分库应用
数据库分表实力创建
create table tb_example_1(
id bigint primary key auto_increment ,
eId bigint,
exampleName varchar(40),
exampleTitle varchar(200),
exampleDate datetime
)ENGINE=MyISAM DEFAULT CHARSET=utf8 AUTO_INCREMENT=1 ; create table tb_example_2 like tb_example_1; create table tb_example_3 like tb_example_1; create table tb_example(
id bigint primary key auto_increment ,
eId bigint,
exampleName varchar(40),
exampleTitle varchar(200),
exampleDate datetime
)ENGINE=MERGE UNION=(tb_example_1,tb_example_2,tb_example_3) INSERT_METHOD=LAST AUTO_INCREMENT=1 ;
程序构建分表操作
1.spring-mybatis-common-data中提供了com.spring.mybatis.data.common.model.ExampleModel用于Demo的实体类
添加maven依赖
<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/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.spring.mybatis</groupId>
<artifactId>com-spring-mybatis-common-data-demo</artifactId>
<packaging>war</packaging>
<version>0.0.1-SNAPSHOT</version>
<name>com-spring-mybatis-common-data-demo Maven Webapp</name>
<url>http://maven.apache.org</url>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<spring.mybatis.data.version>2.0</spring.mybatis.data.version>
<junit.version>4.11</junit.version>
</properties>
<dependencies>
<!-- spring-mybatis-data-common begin -->
<dependency>
<groupId>com.spring.mybatis</groupId>
<artifactId>spring-mybatis-data-common</artifactId>
<version>${spring.mybatis.data.version}</version>
</dependency>
<!-- spring-mybatis-data-common end -->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>${junit.version}</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>0.2.26</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.1</version>
</dependency>
<dependency>
<groupId>org.codehaus.jackson</groupId>
<artifactId>jackson-mapper-asl</artifactId>
<version>1.9.13</version>
</dependency>
</dependencies>
<build>
<finalName>com-spring-mybatis-common-data-demo</finalName>
</build>
</project>
2.持久层继承分表Dao接口,也可以自己定义
@Repository
public interface ExampleModelDao extends ShardCudDao<ExampleModel>,ShardReadDao<ExampleModel>{ /**get common base table max auto_increment id*/
public Long selectMaxId() throws DaoException; }
在持久层自定义了一个selectMaxId()用于多个分表共享同一个自增策略,这里采用程序级别控制
3.业务层继承分表,业务层操作可以自定义,也可以继承com.spring.mybatis.data.common.service.BaseService中提供的常规业务
@Service
public class ExampleModelService extends BaseShard{ @Autowired
private ExampleModelDao exampleModelDao; @Override
public String getBaseShardTableName() {
return "tb_example_";
} @Override
public int getShardTableCount() {
return 3;
} public int deleteObject(ExampleModel entity) throws ServiceException {
try {
return this.exampleModelDao.delete(getShardTableName(entity.geteId()+"", 1), entity.getId());
} catch (DaoException e) {
e.printStackTrace();
}
return 0;
} public int save(ExampleModel entity) throws ServiceException {
long mxId = 1;
try {
Long maxId = this.exampleModelDao.selectMaxId();
if(null != maxId && maxId >= 1){
mxId = maxId + 1;
}
} catch (DaoException e) {
LogUtils.dao.error("insert exampleModel before get Max Id error.",e);
e.printStackTrace();
}
try {
entity.setId(mxId);
return this.exampleModelDao.insert(getShardTableName(entity.geteId()+"", 1), entity);
} catch (DaoException e) {
LogUtils.dao.error("insert exampleModel to table " + getShardTableName(entity.geteId()+"", 1) + " error");
e.printStackTrace();
}
return 0;
} public ExampleModel selectObject(ExampleModel entity)
throws ServiceException {
try {
return this.exampleModelDao.selectById(getShardTableName(entity.geteId()+"", 1), entity.geteId());
} catch (DaoException e) {
e.printStackTrace();
}
return null;
} public void setExampleModelDao(ExampleModelDao exampleModelDao) {
this.exampleModelDao = exampleModelDao;
} }
BaseShard是一个抽象类,继承它需要实现两个方法.
/**
* get shard table count
* @return
*/
public abstract int getShardTableCount(); /**
* get base shard name
* @return
*/
public abstract String getBaseShardTableName();
getShardTableCount()用于返回分表数量, public abstract String getBaseShardTableName()用于返回分表表名统一前缀.
如实例中的分表为tb_example、tb_example_1、tb_example_2、tb_example_3,分表表名前缀为"tb_example_",分表数量为3.
BaseShard中获取映射表名的操作
/**
* get shard table name <br>
*
* shard table index start with 0
*
* just like follows
*
* tb_example_0
* tb_example_1
* tb_example_2
* tb_example_3
*
* @param tableName
* @return
*/
public String getShardTableName(String shardKey); /**
* get shard table name <br>
*
* shard table index start with (0+baseNumber)
*
* just like follows
*
* tb_example_(0+baseNumber)
* tb_example_(1+baseNumber)
* tb_example_(2+baseNumber)
* tb_example_(3+baseNumber)
*
*
* @param shardKey
* @param baseNumber
* @return
*/
public String getShardTableName(String shardKey,int baseNumber);
4.持久层实现
<?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.spring.mybatis.common.data.demo.dao"> <!--insert entity-->
<insert id="insert" parameterType="exampleModel" flushCache="true">
INSERT INTO ${tablename}(
id,
eId,
exampleName,
exampleTitle,
exampleDate)
VALUES(
#{object.id},
#{object.eId},
#{object.exampleName},
#{object.exampleTitle},
#{object.exampleDate}
)
</insert> <select id="selectMaxId" resultType="long">
select max(id) from tb_example
</select> <delete id="delete" parameterType="long" flushCache="true">
DELETE FROM
${tablename}
WHERE
id=#{id}
</delete> <select id="selectById" parameterType="long" resultType="exampleModel">
SELECT
id AS id,eId AS eId,exampleName AS exampleName,exampleTitle AS exampleTitle,exampleDate AS exampleDate
FROM
${tablename}
WHERE
id=#{id}
</select> </mapper>
程序运行结果
查询各个分表
实例下载: http://files.cnblogs.com/dennisit/spring-mybatis-data-common-2.0-and-demo.7z