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系列專欄目錄

[Java項(xiàng)目實(shí)戰(zhàn)] 介紹Java組件安裝、使用；手寫框架等
[Aws服務(wù)器實(shí)戰(zhàn)] Aws Linux服務(wù)器上操作nginx、git、JDK、Vue等
[Java微服務(wù)實(shí)戰(zhàn)] Java 微服務(wù)實(shí)戰(zhàn)，Spring Cloud Netflix套件、Spring Cloud Alibaba套件、Seata、gateway、shadingjdbc等實(shí)戰(zhàn)操作
[Java基礎(chǔ)篇] Java基礎(chǔ)閑聊，已出HashMap、String、StringBuffer等源碼分析，JVM分析，持續(xù)更新中
[Springboot篇] 從創(chuàng)建Springboot項(xiàng)目，到加載數(shù)據(jù)庫、靜態(tài)資源、輸出RestFul接口、跨越問題解決到統(tǒng)一返回、全局異常處理、Swagger文檔
[Spring MVC篇] 從創(chuàng)建Spring MVC項(xiàng)目，到加載數(shù)據(jù)庫、靜態(tài)資源、輸出RestFul接口、跨越問題解決到統(tǒng)一返回
[華為云服務(wù)器實(shí)戰(zhàn)] 華為云Linux服務(wù)器上操作nginx、git、JDK、Vue等，以及使用寶塔運(yùn)維操作添加Html網(wǎng)頁、部署Springboot項(xiàng)目/Vue項(xiàng)目等
[Java爬蟲] 通過Java+Selenium+GoogleWebDriver 模擬真人網(wǎng)頁操作爬取花瓣網(wǎng)圖片、bing搜索圖片等
[Vue實(shí)戰(zhàn)] 講解Vue3的安裝、環(huán)境配置，基本語法、循環(huán)語句、生命周期、路由設(shè)置、組件、axios交互、Element-ui的使用等
[Spring] 講解Spring(Bean)概念、IOC、AOP、集成jdbcTemplate/redis/事務(wù)等

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前言

Apache ShardingSphere 是一款分布式的數(shù)據(jù)庫生態(tài)系統(tǒng)， 可以將任意數(shù)據(jù)庫轉(zhuǎn)換為分布式數(shù)據(jù)庫，并通過數(shù)據(jù)分片、彈性伸縮、加密等能力對原有數(shù)據(jù)庫進(jìn)行增強(qiáng)。

Apache ShardingSphere 設(shè)計哲學(xué)為 Database Plus，旨在構(gòu)建異構(gòu)數(shù)據(jù)庫上層的標(biāo)準(zhǔn)和生態(tài)。 它關(guān)注如何充分合理地利用數(shù)據(jù)庫的計算和存儲能力，而并非實(shí)現(xiàn)一個全新的數(shù)據(jù)庫。 它站在數(shù)據(jù)庫的上層視角，關(guān)注它們之間的協(xié)作多于數(shù)據(jù)庫自身。

1、ShardingSphere-JDBC

ShardingSphere-JDBC 定位為輕量級 Java 框架，在 Java 的 JDBC 層提供的額外服務(wù)。

1.1、應(yīng)用場景

Apache ShardingSphere-JDBC 可以通過Java 和 YAML 這 2 種方式進(jìn)行配置，開發(fā)者可根據(jù)場景選擇適合的配置方式。

• 數(shù)據(jù)庫讀寫分離
• 數(shù)據(jù)庫分表分庫

1.2、原理

• Sharding-JDBC中的路由結(jié)果是通過分片字段和分片方法來確定的,如果查詢條件中有 id 字段的情況還好，查詢將會落到某個具體的分片
• 如果查詢沒有分片的字段，會向所有的db或者是表都會查詢一遍，讓后封裝結(jié)果集給客戶端。
  

1.3、spring boot整合

1.3.1、添加依賴

<!-- 分表分庫依賴 -->
<dependency><groupId>org.apache.shardingsphere</groupId><artifactId>sharding-jdbc-spring-boot-starter</artifactId><version>4.1.1</version>
</dependency>

1.3.2、添加配置

spring:main:# 一個實(shí)體類對應(yīng)多張表，覆蓋allow-bean-definition-overriding: trueshardingsphere:datasource:ds0:#配置數(shù)據(jù)源具體內(nèi)容，包含連接池，驅(qū)動，地址，用戶名和密碼driver-class-name: com.mysql.cj.jdbc.Driverjdbc-url: jdbc:mysql://127.0.0.1:3306/account?autoReconnect=true&allowMultiQueries=truepassword: roottype: com.zaxxer.hikari.HikariDataSourceusername: rootds1:driver-class-name: com.mysql.cj.jdbc.Driverjdbc-url: jdbc:mysql://127.0.0.1:3306/account?autoReconnect=true&allowMultiQueries=truepassword: roottype: com.zaxxer.hikari.HikariDataSourceusername: root# 配置數(shù)據(jù)源，給數(shù)據(jù)源起名稱names: ds0,ds1props:sql:show: truesharding:tables:user_info:#指定 user_info 表分布情況，配置表在哪個數(shù)據(jù)庫里面，表名稱都是什么actual-data-nodes: ds0.user_info_${0..9}database-strategy:standard:preciseAlgorithmClassName: com.xxxx.store.account.config.PreciseDBShardingAlgorithmrangeAlgorithmClassName: com.xxxx.store.account.config.RangeDBShardingAlgorithmsharding-column: idtable-strategy:standard:preciseAlgorithmClassName: com.xxxx.store.account.config.PreciseTablesShardingAlgorithmrangeAlgorithmClassName: com.xxxx.store.account.config.RangeTablesShardingAlgorithmsharding-column: id

1.3.3、制定分片算法

1.3.3.1、精確分庫算法

/*** 精確分庫算法*/
public class PreciseDBShardingAlgorithm implements PreciseShardingAlgorithm<Long> {/**** @param availableTargetNames 配置所有的列表* @param preciseShardingValue 分片值* @return*/@Overridepublic String doSharding(Collection<String> availableTargetNames, PreciseShardingValue<Long> preciseShardingValue) {Long value = preciseShardingValue.getValue();//后綴 0，1String postfix = String.valueOf(value % 2);for (String availableTargetName : availableTargetNames) {if(availableTargetName.endsWith(postfix)){return availableTargetName;}}throw new UnsupportedOperationException();}}

1.3.3.2、范圍分庫算法

/*** 范圍分庫算法*/
public class RangeDBShardingAlgorithm implements RangeShardingAlgorithm<Long> {@Overridepublic Collection<String> doSharding(Collection<String> collection, RangeShardingValue<Long> rangeShardingValue) {return collection;}
}

1.3.3.3、精確分表算法

/*** 精確分表算法*/
public class PreciseTablesShardingAlgorithm implements PreciseShardingAlgorithm<Long> {/**** @param availableTargetNames 配置所有的列表* @param preciseShardingValue 分片值* @return*/@Overridepublic String doSharding(Collection<String> availableTargetNames, PreciseShardingValue<Long> preciseShardingValue) {Long value = preciseShardingValue.getValue();//后綴String postfix = String.valueOf(value % 10);for (String availableTargetName : availableTargetNames) {if(availableTargetName.endsWith(postfix)){return availableTargetName;}}throw new UnsupportedOperationException();}}

1.3.3.4、范圍分表算法

/*** 范圍分表算法*/
public class RangeTablesShardingAlgorithm implements RangeShardingAlgorithm<Long> {@Overridepublic Collection<String> doSharding(Collection<String> collection, RangeShardingValue<Long> rangeShardingValue) {Collection<String> result = new ArrayList<>();Range<Long> valueRange = rangeShardingValue.getValueRange();Long start = valueRange.lowerEndpoint();Long end = valueRange.upperEndpoint();Long min = start % 10;Long max = end % 10;for (Long i = min; i < max +1; i++) {Long finalI = i;collection.forEach(e -> {if(e.endsWith(String.valueOf(finalI))){result.add(e);}});}return result;}}

1.3.4、數(shù)據(jù)庫建表

DROP TABLE IF EXISTS `user_info_0`;
CREATE TABLE `user_info_0` (`id` bigint(20) NOT NULL,`account` varchar(255) DEFAULT NULL,`user_name` varchar(255) DEFAULT NULL,`pwd` varchar(255) DEFAULT NULL,PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

1.3.5、業(yè)務(wù)應(yīng)用

1.3.5.1、定義實(shí)體類

@Data
@TableName(value = "user_info")
public class UserInfo {/*** 主鍵*/private Long id;/*** 賬號*/private String account;/*** 用戶名*/private String userName;/*** 密碼*/private String pwd;}

1.3.5.2、定義接口

public interface UserInfoService{/*** 保存* @param userInfo* @return*/public UserInfo saveUserInfo(UserInfo userInfo);public UserInfo getUserInfoById(Long id);public List<UserInfo> listUserInfo();
}

1.3.5.3、實(shí)現(xiàn)類

@Service
public class UserInfoServiceImpl extends ServiceImpl<UserInfoMapper, UserInfo> implements UserInfoService {@Override@Transactionalpublic UserInfo saveUserInfo(UserInfo userInfo) {userInfo.setId(IdUtils.getId());this.save(userInfo);return userInfo;}@Overridepublic UserInfo getUserInfoById(Long id) {return this.getById(id);}@Overridepublic List<UserInfo> listUserInfo() {QueryWrapper<UserInfo> userInfoQueryWrapper = new QueryWrapper<>();userInfoQueryWrapper.between("id",1623695688380448768L,1623695688380448769L);return this.list(userInfoQueryWrapper);}
}

1.3.6、生成ID - 雪花算法

package com.xxxx.tore.common.utils;import cn.hutool.core.lang.Snowflake;
import cn.hutool.core.util.IdUtil;/*** 生成各種組件ID*/
public class IdUtils {/*** 雪花算法* @return*/public static long getId(){Snowflake snowflake = IdUtil.getSnowflake(0, 0);long id = snowflake.nextId();return id;}
}

1.4、seata與sharding-jdbc整合

https://github.com/seata/seata-samples/tree/master/springcloud-seata-sharding-jdbc-mybatis-plus-samples

1.4.1、common中添加依賴

<!--seata依賴-->
<dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-seata</artifactId><version>2021.0.4.0</version>
</dependency>
<!-- sharding-jdbc整合seata分布式事務(wù)-->
<dependency><groupId>org.apache.shardingsphere</groupId><artifactId>sharding-transaction-base-seata-at</artifactId><version>4.1.1</version>
</dependency><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId><version>2021.0.4.0</version><exclusions><exclusion><groupId>com.alibaba.nacos</groupId><artifactId>nacos-client</artifactId></exclusion></exclusions>
</dependency>
<dependency><groupId>com.alibaba.nacos</groupId><artifactId>nacos-client</artifactId><version>1.4.2</version>
</dependency>

1.4.2、改造account-service服務(wù)

@Service
public class AccountServiceImpl extends ServiceImpl<AccountMapper, Account> implements AccountService {@Autowiredprivate OrderService orderService;@Autowiredprivate StorageService storageService;/*** 存放商品編碼及其對應(yīng)的價錢*/private static Map<String,Integer> map = new HashMap<>();static {map.put("c001",3);map.put("c002",5);map.put("c003",10);map.put("c004",6);}@Override@Transactional@ShardingTransactionType(TransactionType.BASE)public void debit(OrderDTO orderDTO) {//扣減賬戶余額int calculate = this.calculate(orderDTO.getCommodityCode(), orderDTO.getCount());AccountDTO accountDTO = new AccountDTO(orderDTO.getUserId(), calculate);QueryWrapper<Account> objectQueryWrapper = new QueryWrapper<>();objectQueryWrapper.eq("id",1);objectQueryWrapper.eq(accountDTO.getUserId() != null,"user_id",accountDTO.getUserId());Account account = this.getOne(objectQueryWrapper);account.setMoney(account.getMoney() - accountDTO.getMoney());this.saveOrUpdate(account);//扣減庫存this.storageService.deduct(new StorageDTO(null,orderDTO.getCommodityCode(),orderDTO.getCount()));//生成訂單this.orderService.create(orderDTO);      }/*** 計算購買商品的總價錢* @param commodityCode* @param orderCount* @return*/private int calculate(String commodityCode, int orderCount){//商品價錢Integer price = map.get(commodityCode) == null ? 0 : map.get(commodityCode);return price * orderCount;}
}

注意：調(diào)單生成調(diào)用的邏輯修改，減余額->減庫存->生成訂單。調(diào)用入口方法注解加上：@ShardingTransactionType(TransactionType.BASE)

1.4.3、修改business-service服務(wù)

@Service
public class BusinessServiceImpl implements BusinessService {@Autowiredprivate OrderService orderService;@Autowiredprivate StorageService storageService;@Autowiredprivate AccountService accountService;@Overridepublic void purchase(OrderDTO orderDTO) {//扣減賬號中的錢accountService.debit(orderDTO);        }
}

1.4.4、修改order-service服務(wù)

@Service
public class OrderServiceImpl extends ServiceImpl<OrderMapper,Order> implements OrderService {/*** 存放商品編碼及其對應(yīng)的價錢*/private static Map<String,Integer> map = new HashMap<>();static {map.put("c001",3);map.put("c002",5);map.put("c003",10);map.put("c004",6);}@Override@Transactional@ShardingTransactionType(TransactionType.BASE)public Order create(String userId, String commodityCode, int orderCount) {int orderMoney = calculate(commodityCode, orderCount);Order order = new Order();order.setUserId(userId);order.setCommodityCode(commodityCode);order.setCount(orderCount);order.setMoney(orderMoney);//保存訂單this.save(order);try {TimeUnit.SECONDS.sleep(30);} catch (InterruptedException e) {e.printStackTrace();}if(true){throw new RuntimeException("回滾測試");}return order;}/*** 計算購買商品的總價錢* @param commodityCode* @param orderCount* @return*/private int calculate(String commodityCode, int orderCount){//商品價錢Integer price = map.get(commodityCode) == null ? 0 : map.get(commodityCode);return price * orderCount;}
}

1.4.5、配置文件參考

server:port: 8090spring:main:# 一個實(shí)體類對應(yīng)多張表，覆蓋allow-bean-definition-overriding: trueshardingsphere:datasource:ds0:#配置數(shù)據(jù)源具體內(nèi)容，包含連接池，驅(qū)動，地址，用戶名和密碼driver-class-name: com.mysql.cj.jdbc.Driverjdbc-url: jdbc:mysql://127.0.0.1:3306/account?autoReconnect=true&allowMultiQueries=truepassword: roottype: com.zaxxer.hikari.HikariDataSourceusername: rootds1:driver-class-name: com.mysql.cj.jdbc.Driverjdbc-url: jdbc:mysql://127.0.0.1:3306/account?autoReconnect=true&allowMultiQueries=truepassword: roottype: com.zaxxer.hikari.HikariDataSourceusername: root# 配置數(shù)據(jù)源，給數(shù)據(jù)源起名稱names: ds0,ds1props:sql:show: truesharding:tables:account_tbl:actual-data-nodes: ds0.account_tbl_${0..1}database-strategy:standard:preciseAlgorithmClassName: com.xxxx.store.account.config.PreciseDBExtShardingAlgorithm#rangeAlgorithmClassName: com.xxxx.store.account.config.RangeDBShardingAlgorithmsharding-column: idtable-strategy:standard:preciseAlgorithmClassName: com.xxxx.store.account.config.PreciseTablesExtShardingAlgorithm#rangeAlgorithmClassName: com.xxxx.store.account.config.RangeTablesShardingAlgorithmsharding-column: iduser_info:#指定 user_info 表分布情況，配置表在哪個數(shù)據(jù)庫里面，表名稱都是什么actual-data-nodes: ds0.user_info_${0..9}database-strategy:standard:preciseAlgorithmClassName: com.xxxx.store.account.config.PreciseDBShardingAlgorithmrangeAlgorithmClassName: com.xxxx.store.account.config.RangeDBShardingAlgorithmsharding-column: idtable-strategy:standard:preciseAlgorithmClassName: com.xxxx.store.account.config.PreciseTablesShardingAlgorithmrangeAlgorithmClassName: com.xxxx.store.account.config.RangeTablesShardingAlgorithmsharding-column: id#以上是sharding-jdbc配置cloud:nacos:discovery:server-addr: localhost:8848namespace: 1ff3782d-b62d-402f-8bc4-ebcf40254d0aapplication:name: account-service  #微服務(wù)名稱
#  datasource:
#    username: root
#    password: root
#    url: jdbc:mysql://127.0.0.1:3306/account
#    driver-class-name: com.mysql.cj.jdbc.Driverseata:enabled: trueenable-auto-data-source-proxy: falseapplication-id: account-servicetx-service-group: default_tx_groupservice:vgroup-mapping:default_tx_group: defaultdisable-global-transaction: falseregistry:type: nacosnacos:application: seata-serverserver-addr: 127.0.0.1:8848namespace: 1ff3782d-b62d-402f-8bc4-ebcf40254d0agroup: SEATA_GROUPusername: nacospassword: nacosconfig:nacos:server-addr: 127.0.0.1:8848namespace: 1ff3782d-b62d-402f-8bc4-ebcf40254d0agroup: SEATA_GROUPusername: nacospassword: nacos

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聯(lián)系方式

微信公眾號：Java微服務(wù)架構(gòu)

系列文章目錄

第一章 Java線程池技術(shù)應(yīng)用
第二章 CountDownLatch和Semaphone的應(yīng)用
第三章 Spring Cloud 簡介
第四章 Spring Cloud Netflix 之 Eureka
第五章 Spring Cloud Netflix 之 Ribbon
第六章 Spring Cloud 之 OpenFeign
第七章 Spring Cloud 之 GateWay
第八章 Spring Cloud Netflix 之 Hystrix
第九章 代碼管理gitlab 使用
第十章 SpringCloud Alibaba 之 Nacos discovery
第十一章 SpringCloud Alibaba 之 Nacos Config
第十二章 Spring Cloud Alibaba 之 Sentinel
第十三章 JWT
第十四章 RabbitMQ應(yīng)用
第十五章 RabbitMQ 延遲隊(duì)列
第十六章 spring-cloud-stream
第十七章 Windows系統(tǒng)安裝Redis、配置環(huán)境變量
第十八章 查看、修改Redis配置，介紹Redis類型
第十九章 ShardingSphere - ShardingSphere-JDBC