SpringBoot使用Sharding-JDBC讀寫分離

時間 2019-11-30

標籤 springboot 使用 sharding jdbc 讀寫分離欄目 Spring 简体版

原文原文鏈接

本文介紹SpringBoot使用噹噹Sharding-JDBC進行讀寫分離。java

1.有關Sharding-JDBC

本文仍是基於噹噹網Sharding-Jdbc的依賴，與上一篇使用Sharding-Jdbc進行分庫分表依賴一致，而且本文大體內容與上一篇文章類似，建議先查看個人另外一篇在查看這篇會簡單許多，傳送門《SpringBoot使用Sharding-JDBC分庫分表》。mysql

這裏須要特殊介紹的是，使用Sharding-JDBC進行讀寫分離的時候，只容許設置一個主庫，從庫的話能夠設置多個，訪問策略的話從源碼上看只有兩種輪詢（ROUND_ROBIN）和隨機（RANDOM）。git

源碼代碼以下:web

package com.dangdang.ddframe.rdb.sharding.api.strategy.slave;

public enum MasterSlaveLoadBalanceStrategyType {
    ROUND_ROBIN(new RoundRobinMasterSlaveLoadBalanceStrategy()),
    RANDOM(new RandomMasterSlaveLoadBalanceStrategy());

    private final MasterSlaveLoadBalanceStrategy strategy;

    public static MasterSlaveLoadBalanceStrategyType getDefaultStrategyType() {
        return ROUND_ROBIN;
    }

    private MasterSlaveLoadBalanceStrategyType(MasterSlaveLoadBalanceStrategy strategy) {
        this.strategy = strategy;
    }

    public MasterSlaveLoadBalanceStrategy getStrategy() {
        return this.strategy;
    }
}
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2.本文場景

因爲本地環境並無使用Mysql主從複製，只是建立了三個庫，其中database0做爲主庫，database1和database2做爲從庫。主庫進行增刪改操做，從庫進行查詢操做，以下圖爲本文數據庫的三個表。spring

如上圖分別是三個數據庫中的user表，其中master-user爲database0數據庫中的user表，salve-user1爲database1中的user表，salve-user2爲database2中的user表。sql

3.代碼實現

本文使用SpringBoot2.0.3，SpringData-JPA，Druid鏈接池，和噹噹的sharding-jdbc。數據庫

3.1 建表SQL

建立表和數據庫的SQL以下所示，這裏默認在從庫內分別插入了一條數據，name值分別存放dalaoyang1和dalaoyang2便於區分。apache

CREATE DATABASE database0;
USE database0;
DROP TABLE IF EXISTS `user`;
CREATE TABLE `user`(
	id bigint(64) not null,
	city varchar(20) not null,
	name varchar(20) not null,
	PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

CREATE DATABASE database1;
USE database1;
DROP TABLE IF EXISTS `user`;
CREATE TABLE `user`(
	id bigint(64) not null,
	city varchar(20) not null,
	name varchar(20) not null,
	PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
INSERT INTO `database1`.`user`(`id`, `city`, `name`) VALUES (101, 'beijing', 'dalaoyang1');

CREATE DATABASE database2;
USE database2;
DROP TABLE IF EXISTS `user`;
CREATE TABLE `user`(
	id bigint(64) not null,
	city varchar(20) not null,
	name varchar(20) not null,
	PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
INSERT INTO `database2`.`user`(`id`, `city`, `name`) VALUES (102, 'beijing', 'dalaoyang2');
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3.2 依賴文件

新建項目，依賴文件仍是噹噹的sharding-jdbc-core依賴和druid鏈接池，完整pom文件代碼以下所示。api

<?xml version="1.0" encoding="UTF-8"?>
<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>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.3.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.dalaoyang</groupId>
    <artifactId>springboot2_shardingjdbc_dxfl</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>springboot2_shardingjdbc_dxfl</name>
    <description>springboot2_shardingjdbc_dxfl</description>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <!-- lombok -->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <!-- druid -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.1.9</version>
        </dependency>
        <!-- sharding-jdbc -->
        <dependency>
            <groupId>com.dangdang</groupId>
            <artifactId>sharding-jdbc-core</artifactId>
            <version>1.5.4</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

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3.3 配置信息

在配置信息中配置了三個數據庫的信息和JPA的簡單配置。springboot

##Jpa配置
spring.jpa.database=mysql
spring.jpa.show-sql=true
spring.jpa.hibernate.ddl-auto=none

##數據庫配置
##數據庫database0地址
database0.url=jdbc:mysql://localhost:3306/database0?characterEncoding=utf8&useSSL=false
##數據庫database0用戶名
database0.username=root
##數據庫database0密碼
database0.password=root
##數據庫database0驅動
database0.driverClassName=com.mysql.jdbc.Driver
##數據庫database0名稱
database0.databaseName=database0

##數據庫database1地址
database1.url=jdbc:mysql://localhost:3306/database1?characterEncoding=utf8&useSSL=false
##數據庫database1用戶名
database1.username=root
##數據庫database1密碼
database1.password=root
##數據庫database1驅動
database1.driverClassName=com.mysql.jdbc.Driver
##數據庫database1名稱
database1.databaseName=database1

##數據庫database2地址
database2.url=jdbc:mysql://localhost:3306/database2?characterEncoding=utf8&useSSL=false
##數據庫database1用戶名
database2.username=root
##數據庫database1密碼
database2.password=root
##數據庫database1驅動
database2.driverClassName=com.mysql.jdbc.Driver
##數據庫database1名稱
database2.databaseName=database2
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3.4 啓動類

上一篇文章說到在啓動類加入了@EnableAutoConfiguration去除數據庫自動配置，當時也沒太注意，其實能夠直接在@SpringBootApplication註解上去除數據庫自動配置，剩下的和上一篇同樣，使用@EnableTransactionManagement開啓事務，使用@EnableConfigurationProperties註解加入配置實體，啓動類完整代碼以下所示。

package com.dalaoyang;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.transaction.annotation.EnableTransactionManagement;

@SpringBootApplication(exclude = {DataSourceAutoConfiguration.class})
@EnableTransactionManagement(proxyTargetClass = true)
@EnableConfigurationProperties
public class Springboot2ShardingjdbcDxflApplication {

    public static void main(String[] args) {
        SpringApplication.run(Springboot2ShardingjdbcDxflApplication.class, args);
    }

}
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3.5 實體類和數據庫操做層

User實體類。

package com.dalaoyang.entity;

import lombok.Data;

import javax.persistence.*;

@Entity
@Table(name="user")
@Data
public class User {

    @Id
    private Long id;

    private String city;

    private String name;
}

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UserRepository類。

package com.dalaoyang.repository;

import com.dalaoyang.entity.User;
import org.springframework.data.jpa.repository.JpaRepository;

public interface UserRepository extends JpaRepository<User,Long> {
}

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3.6 數據庫參數類

數據庫配置類，Database0Config。

package com.dalaoyang.database;

import com.alibaba.druid.pool.DruidDataSource;
import lombok.Data;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;

import javax.sql.DataSource;

/**
 * @author yangyang
 * @date 2019/1/30
 */
@Data
@ConfigurationProperties(prefix = "database0")
@Component
public class Database0Config {
    private String url;
    private String username;
    private String password;
    private String driverClassName;
    private String databaseName;

    public DataSource createDataSource() {
        DruidDataSource result = new DruidDataSource();
        result.setDriverClassName(getDriverClassName());
        result.setUrl(getUrl());
        result.setUsername(getUsername());
        result.setPassword(getPassword());
        return result;
    }
}

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數據庫配置類，Database1Config。

package com.dalaoyang.database;

import com.alibaba.druid.pool.DruidDataSource;
import lombok.Data;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;

import javax.sql.DataSource;

/**
 * @author yangyang
 * @date 2019/1/30
 */
@Data
@ConfigurationProperties(prefix = "database1")
@Component
public class Database1Config {
    private String url;
    private String username;
    private String password;
    private String driverClassName;
    private String databaseName;

    public DataSource createDataSource() {
        DruidDataSource result = new DruidDataSource();
        result.setDriverClassName(getDriverClassName());
        result.setUrl(getUrl());
        result.setUsername(getUsername());
        result.setPassword(getPassword());
        return result;
    }
}

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數據庫配置類，Database2Config。

package com.dalaoyang.database;

import com.alibaba.druid.pool.DruidDataSource;
import lombok.Data;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;

import javax.sql.DataSource;

/**
 * @author yangyang
 * @date 2019/1/30
 */
@Data
@ConfigurationProperties(prefix = "database2")
@Component
public class Database2Config {
    private String url;
    private String username;
    private String password;
    private String driverClassName;
    private String databaseName;

    public DataSource createDataSource() {
        DruidDataSource result = new DruidDataSource();
        result.setDriverClassName(getDriverClassName());
        result.setUrl(getUrl());
        result.setUsername(getUsername());
        result.setPassword(getPassword());
        return result;
    }
}

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3.7 讀寫分離配置

建立一個DataSourceConfig類來設置讀寫分離，這裏其實也與分庫分表相似，也能夠在分庫分表的基礎上進行讀寫分離，須要建立一個Map集合來接收從庫。在建立數據源時須要傳入五個參數，分別是：

name：數據源名稱
masterDataSourceName：主庫數據源名稱
masterDataSource：主數據源
slaveDataSourceMap：從數據源集合
strategyType：訪問策略

固然，也可使用其餘方法建立數據源，本文代碼以下：

package com.dalaoyang.database;


import com.dangdang.ddframe.rdb.sharding.api.MasterSlaveDataSourceFactory;
import com.dangdang.ddframe.rdb.sharding.api.strategy.slave.MasterSlaveLoadBalanceStrategyType;
import com.dangdang.ddframe.rdb.sharding.keygen.DefaultKeyGenerator;
import com.dangdang.ddframe.rdb.sharding.keygen.KeyGenerator;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import javax.sql.DataSource;
import java.sql.SQLException;
import java.util.HashMap;
import java.util.Map;

/**
 * @author yangyang
 * @date 2019/1/29
 */
@Configuration
public class DataSourceConfig {

    @Autowired
    private Database0Config database0Config;

    @Autowired
    private Database1Config database1Config;

    @Autowired
    private Database2Config database2Config;

    @Bean
    public DataSource getDataSource() throws SQLException {
        return buildDataSource();
    }

    private DataSource buildDataSource() throws SQLException {
        //設置從庫數據源集合
        Map<String, DataSource> slaveDataSourceMap = new HashMap<>();
        slaveDataSourceMap.put(database1Config.getDatabaseName(), database1Config.createDataSource());
        slaveDataSourceMap.put(database2Config.getDatabaseName(), database2Config.createDataSource());

        //獲取數據源對象
        DataSource dataSource = MasterSlaveDataSourceFactory.createDataSource("masterSlave",database0Config.getDatabaseName()
                ,database0Config.createDataSource(), slaveDataSourceMap, MasterSlaveLoadBalanceStrategyType.getDefaultStrategyType());
        return dataSource;
    }


    @Bean
    public KeyGenerator keyGenerator() {
        return new DefaultKeyGenerator();
    }

}

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3.8 Controller

Controller作爲測試類，建立兩個方法，save方法和getAll方法，其中：

save方法用於測試主庫的插入和修改
getAll方法用於測試讀數據

UserController類以下所示。

package com.dalaoyang.controller;

import com.dalaoyang.entity.User;
import com.dalaoyang.repository.UserRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class UserController {

    @Autowired
    private UserRepository userRepository;

    @GetMapping("save")
    public void save(){
        User user = new User();
        user.setId(100L);
        user.setName("dalaoyang");
        user.setCity("beijing");
        userRepository.save(user);
    }

    @GetMapping("getAll")
    public Object getAll(){
        return userRepository.findAll();
    }
}

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