spring-mybatis-data-common程序级分表操作实例

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

转载请注明地址:[http://www.cnblogs.com/dennisit/p/3793501.html]