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Spring?AOP實(shí)現(xiàn)多數(shù)據(jù)源動(dòng)態(tài)切換

 更新時(shí)間:2022年03月14日 09:58:43   作者:Carson-Zhao  
本文主要介紹了Spring?AOP實(shí)現(xiàn)多數(shù)據(jù)源動(dòng)態(tài)切換,文中通過示例代碼介紹的非常詳細(xì),具有一定的參考價(jià)值,感興趣的小伙伴們可以參考一下

需求背景

去年底,公司項(xiàng)目有一個(gè)需求中有個(gè)接口需要用到平臺(tái)、算法、大數(shù)據(jù)等三個(gè)不同數(shù)據(jù)庫(kù)的數(shù)據(jù)進(jìn)行計(jì)算、組裝以及最后的展示,當(dāng)時(shí)這個(gè)需求是另一個(gè)老同事在做,我只是負(fù)責(zé)自己的部分。
直到今年回來(lái)了,這個(gè)項(xiàng)目也做得差不多了,這會(huì)兒才有時(shí)間區(qū)仔細(xì)看同事的代碼,是怎么去實(shí)現(xiàn)多數(shù)據(jù)源動(dòng)態(tài)切換的。

擴(kuò)展:當(dāng)業(yè)務(wù)也來(lái)越復(fù)雜,數(shù)據(jù)量越來(lái)越龐大時(shí),就可能會(huì)對(duì)數(shù)據(jù)庫(kù)進(jìn)行分庫(kù)分表、讀寫分離等設(shè)計(jì)來(lái)減輕壓力、提高系統(tǒng)性能,那么多數(shù)據(jù)源動(dòng)態(tài)切換勢(shì)必是必不可少!

經(jīng)過了一星期零零碎碎的下班時(shí)間,從了解原理、實(shí)現(xiàn)、優(yōu)化的過程,自己終于總算是弄出來(lái)了,接下來(lái)一起看看!

思考

  • 如何讓Spring知道我們配置了多個(gè)數(shù)據(jù)源?
  • 配置了多個(gè)數(shù)據(jù)源后,Spring是如何決定使用哪一個(gè)數(shù)據(jù)源?
  • Spring是如何動(dòng)態(tài)切換數(shù)據(jù)源?

分析及實(shí)現(xiàn)

配置多數(shù)據(jù)源信息

spring:
  datasource:
    local:
      database: local
      username: root
      password: 
      jdbc-url: jdbc:mysql://ip:port/test_user?useUnicode=true&characterEncoding=utf-8&useSSL=true&serverTimezone=UTC
      driver-class-name: com.mysql.cj.jdbc.Driver
    server:
      database: server
      username: root
      password: 
      jdbc-url: jdbc:mysql://ip:port/test_user?useUnicode=true&characterEncoding=utf-8&useSSL=true&serverTimezone=UTC
      driver-class-name: com.mysql.cj.jdbc.Driver

這是我的兩個(gè)數(shù)據(jù)庫(kù):本地?cái)?shù)據(jù)庫(kù)+個(gè)人服務(wù)器數(shù)據(jù)庫(kù)

服務(wù)器數(shù)據(jù)庫(kù)

本地?cái)?shù)據(jù)庫(kù)

Spring如何獲取配置好的多個(gè)數(shù)據(jù)源信息?

Spring提供了三種方式進(jìn)行獲取

@Value注解獲?。▽?shí)體類需配合@Component),最簡(jiǎn)單,但當(dāng)配置信息較多時(shí),寫起來(lái)比較繁瑣

@ConfigurationProperties注解獲取,需要定義前綴,可大批量獲取配置信息

@Environment注解從Spring環(huán)境中獲取,實(shí)現(xiàn)較為復(fù)雜,本人很少用

同事使用的方式是第一種方式,但是我個(gè)人覺得這樣侵入性較大,每增加一個(gè)數(shù)據(jù)源,就要重新定義變量然后用@Value去重新配置,很麻煩,所以我就選擇了第二種方式

通過@ConfigurationProperties注解獲取,需要定義前綴,可大批量獲取配置信息

@Data
@Component
@ConfigurationProperties(prefix = "spring.datasource")
public class DBProperties {
 
    private HikariDataSource server;
 
    private HikariDataSource local;
}

將所有的數(shù)據(jù)源加載到Spring中,可供其選擇使用

@Slf4j
@Configuration
public class DataSourceConfig {
 
    @Autowired
    private DBProperties dbProperties;
 
    @Bean(name = "multiDataSource")
    public MultiDataSource multiDataSource(){
        MultiDataSource multiDataSource = new MultiDataSource();
        //1.設(shè)置默認(rèn)數(shù)據(jù)源
        multiDataSource .setDefaultTargetDataSource(dbProperties.getLocal());
        //2.配置多數(shù)據(jù)源
        HashMap<Object, Object> dataSourceMap = Maps.newHashMap();
 
        dataSourceMap.put("local", dbProperties.getLocal());
        dataSourceMap.put("server", dbProperties.getServer());
        //3.存放數(shù)據(jù)源集
        multiDataSource.setTargetDataSources(dataSourceMap);
        return multiDataSource;
    }
}

如此之后,確實(shí)是可以讀取YML中的數(shù)據(jù)源信息,但是總覺得怪怪的。
果然!當(dāng)我實(shí)現(xiàn)了整個(gè)功能后,我發(fā)現(xiàn),如果我想要再加一個(gè)數(shù)據(jù)源,我還是得去求改DBProperties和DataSourceConfig這兩類的內(nèi)容,就很煩,我這個(gè)人比較懶,所以我就將這部分內(nèi)容優(yōu)化了一下:

優(yōu)化后的YML

spring:
  datasource:
    names:
       - database: dataSource0
         username: root
         password: 
         jdbc-url: jdbc:mysql://ip:port/test_user?useUnicode=true&characterEncoding=utf-8&useSSL=true&serverTimezone=UTC
         driver-class-name: com.mysql.cj.jdbc.Driver
       - database: dataSource1
         username: root
         password: 
         jdbc-url: jdbc:mysql://ip:port/test_user?useUnicode=true&characterEncoding=utf-8&useSSL=true&serverTimezone=UTC
         driver-class-name: com.mysql.cj.jdbc.Driver

優(yōu)化后的DBProperties

@Data
@Component
@ConfigurationProperties(prefix = "spring.datasource")
public class DBProperties {
 
    private List<HikariDataSource> DBNames;
 
}

優(yōu)化后的DataSourceConfig

@Slf4j
@Configuration
public class DataSourceConfig {
 
    @Autowired
    private DBProperties dbProperties;
 
 
    @Bean(name = "multiDataSource")
    public MultiDataSource multiDataSource(){
        MultiDataSource multiDataSource = new MultiDataSource();
        
        List<HikariDataSource> names = dbProperties.getNames();
        if (CollectionUtils.isEmpty(names)){
            throw new RuntimeException(" please configure the data source! ");
        }
 
        multiDataSource.setDefaultTargetDataSource(names.get(0));
 
        HashMap<Object, Object> dataSourceMap = Maps.newHashMap();
        int i = 0;
        for (HikariDataSource name : names) {
            dataSourceMap.put("dataSource"+(i++),name);
        }
 
        multiDataSource.setTargetDataSources(dataSourceMap);
        return multiDataSource;
    }
}

這樣子,我之后無(wú)論配置了多少個(gè)數(shù)據(jù)源信息,我都不需要再去修改配置代碼

Spring如何選擇使用數(shù)據(jù)源?

選擇一個(gè)數(shù)據(jù)源

通過繼承AbstractRoutingDataSource接口,重寫determineCurrentLookupKey方法,選擇具體的數(shù)據(jù)源

@Slf4j
public class MultiDataSource extends AbstractRoutingDataSource {
    
    @Override
    protected Object determineCurrentLookupKey() {
 
        return MultiDataSourceHolder.getDatasource();
 
    }
    
}

利用ThreadLocal實(shí)現(xiàn)數(shù)據(jù)源線程隔離

public class MultiDataSourceHolder {
 
    private static final ThreadLocal<String> threadLocal =new ThreadLocal<>();
 
    public static void setDatasource(String datasource){
        threadLocal.set(datasource);
    }
 
    public static String getDatasource(){
        return threadLocal.get();
    }
 
    public static void clearDataSource(){
        threadLocal.remove();
    }
 
}

準(zhǔn)備工作做好,下面開始將動(dòng)態(tài)切換操作串聯(lián)起來(lái)

利用AOP切面+自定義注解

自定義注解

@Target({ElementType.METHOD,ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface MultiDataSource {
 
    String DBName();
 
}

AOP切面

@Slf4j
@Aspect
@Component
public class DataSourceAspect {
 
    @Pointcut(value = "@within(com.xiaozhao.base.aop.annotation.MultiDataSource) || @annotation(com.xiaozhao.base.aop.annotation.MultiDataSource)")
    public void dataSourcePointCut(){}
 
 
    @Before("dataSourcePointCut() && @annotation(multiDataSource)")
    public void before(MultiDataSource multiDataSource){
 
        String dbName = multiDataSource.DBName();
 
        if (StringUtils.hasLength(dbName)){
 
            MultiDataSourceHolder.setDatasource(multiDataSource.DBName());
            log.info("current dataSourceName ====== "+dbName);
 
        }else {
 
            log.info("switch datasource fail, use default, or please configure the data source for the annotations,");
 
        }
    }
 
 
    @After("dataSourcePointCut()")
    public void after(){
        MultiDataSourceHolder.clearDataSource();
    }
}

好了!功能已然實(shí)現(xiàn),打完收工!

。。。。

如果我工作中也這樣,估計(jì)要被測(cè)試打死!為了敷衍一下,來(lái)進(jìn)行一下測(cè)試

一套代碼直接打完:

Controller+Service+Dao

@RestController
@RequestMapping("user")
public class UserController {
 
    @Autowired
    private UserService userService;
 
 
 
    @GetMapping("/info")
    public UserVO getUser(){
        return userService.creatUser();
    }
}
 
 
 
 
public interface UserService {
    UserVO creatUser();
 
    UserVO setUserInfo(String phone);
}
 
 
 
 
@Service
@EnableAspectJAutoProxy(exposeProxy = true)
public class UserServiceImpl implements UserService {
 
    @Autowired
    private UserMapper userMapper;
 
    @Autowired
    private InfoMapper infoMapper;
 
 
    @Override
    public UserVO creatUser() {
        UserVO userVO = userMapper.getUserInfoMapper();
 
        return ((UserService) AopContext.currentProxy()).setUserInfo(userVO.getPhone());
    }
 
    @MultiDataSource(DBName = "dataSource1")
    public UserVO setUserInfo(String phone) {
 
        UserVO userInfo = infoMapper.getUserInfo();
 
        UserVO user = new UserVO();
        user.setUserName(userInfo.getUserName());
        user.setPassword(userInfo.getPassword());
        user.setAddress(userInfo.getAddress());
        user.setPhone(phone);
        return user;
    }
}
 
 
 
 
@Mapper
public interface InfoMapper {
 
    @Select("select id,user_name as userName,password,phone,address from test_user")
    UserVO getUserInfo();
}
 
 
 
@Mapper
public interface UserMapper {
 
    @Select("select id,user_name as userName,password,phone from user")
    UserVO getUserInfoMapper();
 
}

測(cè)試結(jié)果:紅框數(shù)據(jù)來(lái)自于服務(wù)器數(shù)據(jù)庫(kù),綠框數(shù)據(jù)來(lái)自于本地?cái)?shù)據(jù)庫(kù)

遇到的問題同一個(gè)類中,A方法調(diào)用B方法用AopContext.currentProxy()報(bào)錯(cuò)問題:在類上加@EnableAspectJAutoProxy(exposeProxy = true)————解決!配置多數(shù)據(jù)源時(shí),注意將url修改成jdbc-url切面時(shí),用JoinPoint獲取方法,判斷是否被注解修飾(雖然純屬多余)結(jié)果為false————有待考究!

結(jié)語(yǔ)

到此這篇關(guān)于Spring AOP實(shí)現(xiàn)多數(shù)據(jù)源動(dòng)態(tài)切換的文章就介紹到這了,更多相關(guān)Spring AOP多數(shù)據(jù)源動(dòng)態(tài)切換內(nèi)容請(qǐng)搜索腳本之家以前的文章或繼續(xù)瀏覽下面的相關(guān)文章希望大家以后多多支持腳本之家!

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