1.實(shí)現(xiàn)的功能
基于springboot框架，application.yml配置多個(gè)數(shù)據(jù)源，使用AOP以及AbstractRootingDataSource、ThreadLocal來(lái)實(shí)現(xiàn)多數(shù)據(jù)源切換，以實(shí)現(xiàn)讀寫分離。mysql的主從數(shù)據(jù)庫(kù)需要進(jìn)行設(shè)置數(shù)據(jù)之間的同步。
2.代碼實(shí)現(xiàn)
application.properties中的配置
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spring.datasource.druid.master.driver-class-name=com.mysql.jdbc.Driverspring.datasource.druid.master.url=jdbc:mysql://127.0.0.1:3306/node2?useUnicode=true&characterEncoding=UTF-8&allowMultiQueries=true&autoReconnect=true&useSSL=falsespring.datasource.druid.master.username=rootspring.datasource.druid.master.password=123456 spring.datasource.druid.slave.driver-class-name=com.mysql.jdbc.Driverspring.datasource.druid.slave.url=jdbc:mysql://127.0.0.1:3306/node1?useUnicode=true&characterEncoding=UTF-8&allowMultiQueries=true&autoReconnect=true&useSSL=falsespring.datasource.druid.slave.username=rootspring.datasource.druid.slave.password=123456 |
寫一個(gè)DataSourceConfig.java來(lái)注入兩個(gè)bean
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@Bean @ConfigurationProperties("spring.datasource.druid.master") public DataSource masterDataSource() { logger.info("select master data source"); return DruidDataSourceBuilder.create().build(); } @Bean @ConfigurationProperties("spring.datasource.druid.slave") public DataSource slaveDataSource() { logger.info("select slave data source"); return DruidDataSourceBuilder.create().build(); } |
寫一個(gè)enum來(lái)標(biāo)識(shí)有哪些數(shù)據(jù)源
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public enum DBTypeEnum { MASTER, SLAVE;} |
然后寫一個(gè)ThreadLocal本地線程的管理類,用于設(shè)置當(dāng)前線程是那一個(gè)數(shù)據(jù)源
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private static final ThreadLocal<DBTypeEnum> contextHolder = new ThreadLocal<>(); private static final ThreadLocal<DBTypeEnum> contextHolder2 = ThreadLocal.withInitial(() -> DBTypeEnum.MASTER); public static void set(DBTypeEnum dbType) { contextHolder.set(dbType); } public static DBTypeEnum get() { return contextHolder.get(); } public static void master() { set(DBTypeEnum.MASTER); logger.info("切換到master數(shù)據(jù)源"); } public static void slave() { set(DBTypeEnum.SLAVE); logger.info("切換到slave數(shù)據(jù)源"); } public static void cleanAll() { contextHolder.remove(); } |
然后寫一個(gè)DynamicDataSource繼承AbstractRootingDataSource,重寫它的determineCurrentLookupKey方法。
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public class DynamicDataSource extends AbstractRoutingDataSource { private Logger logger = LogManager.getLogger(DynamicDataSource.class); @Override protected Object determineCurrentLookupKey() { logger.info("此時(shí)數(shù)據(jù)源為{}", DBContextHolder.get()); return DBContextHolder.get(); }} |
最后寫一個(gè)AOP來(lái)實(shí)現(xiàn)數(shù)據(jù)源切換
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@Aspect@Order(1)@Componentpublic class DataSourceAop { private Logger logger = LogManager.getLogger(DataSourceAop.class); @Pointcut("(execution(* com.springboot.demo.service..*.select*(..)) " + "|| execution(* com.springboot.demo.service..*.find*(..)) " + "|| execution(* com.springboot.demo.service..*.get*(..)))") public void readPointcut() { logger.info("read only operate ,into slave db"); } @Pointcut("execution(* com.springboot.demo.service..*.insert*(..)) " + "|| execution(* com.springboot.demo.service..*.update*(..)) " + "|| execution(* com.springboot.demo.service..*.delete*(..)) ") public void writePointcut() { logger.info("read or write operate ,into master db"); } @Before("readPointcut()") public void read() { logger.info("read operate"); DBContextHolder.slave(); } @Before("writePointcut()") public void write() { logger.info("write operate"); DBContextHolder.master(); } @After("writePointcut(),readPointcut()") public void clean() { logger.info("dataSource cleanAll"); DBContextHolder.cleanAll(); }} |
注意：這里只是使用了偷懶的方法，對(duì)于service里面的select、get、find前綴的方法都使用從庫(kù)，對(duì)于insert、update和delete方法都使用主庫(kù)。
可以使用注解如下來(lái)進(jìn)行優(yōu)化:
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@Retention(RetentionPolicy.RUNTIME)@Target(ElementType.METHOD)public @interface DataSource { @AliasFor("dataSource") DBTypeEnum value() default DBTypeEnum.MASTER; DBTypeEnum dataSource() default DBTypeEnum.MASTER;} |
使用此注解來(lái)放入到service方法上，
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@DataSource(DBTypeEnum.SLAVE) |
然后AOP方法修改為：
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private static final String POINT = "execution (* com.springboot.demo.service.*.*(..))"; @Around(POINT) public Object dataSourceAround(ProceedingJoinPoint joinPoint) throws Throwable { Object[] args = joinPoint.getArgs(); Object obj; Object target = joinPoint.getTarget(); String methodName = joinPoint.getSignature().getName(); Class clazz = target.getClass(); Class<?>[] parameterTypes = ((MethodSignature) joinPoint.getSignature()).getMethod().getParameterTypes(); boolean isDynamicDataSourceMethod = false; try { Method method = clazz.getMethod(methodName, parameterTypes); DataSources currentDataSource = null; if (method != null && method.isAnnotationPresent(DataSource.class)) { isDynamicDataSourceMethod = true; currentDataSource = method.getAnnotation(DataSource.class).value(); DataSourceTypeManager.set(currentDataSource); log.info("DataSourceInterceptor Switch DataSource To {}",currentDataSource); } obj = joinPoint.proceed(args); if (isDynamicDataSourceMethod) { log.info("DataSourceInterceptor DataSource {} proceed",currentDataSource); } } finally { if (isDynamicDataSourceMethod) { DataSourceTypeManager.reset(); log.info("DataSourceInterceptor Reset DataSource To {}",DataSourceTypeManager.get()); } } return obj; } |
到此這篇關(guān)于springboot結(jié)合mysql主從來(lái)實(shí)現(xiàn)讀寫分離的方法示例的文章就介紹到這了,更多相關(guān)springboot 讀寫分離內(nèi)容請(qǐng)搜索服務(wù)器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服務(wù)器之家！
原文鏈接：https://blog.csdn.net/yancun93/article/details/103958645
