SpringBoot+aop實現(xiàn)主從數(shù)據(jù)庫的讀寫分離操作
讀寫分離的作用是為了緩解寫庫,也就是主庫的壓力,但一定要基于數(shù)據(jù)一致性的原則,就是保證主從庫之間的數(shù)據(jù)一定要一致。如果一個方法涉及到寫的邏輯,那么該方法里所有的數(shù)據(jù)庫操作都要走主庫。
一、環(huán)境部署
- 數(shù)據(jù)庫:MySql
- 2個,一主一從
DROP TABLE IF EXISTS `user`;
CREATE TABLE `user` (
`user_id` bigint(20) NOT NULL COMMENT '用戶id',
`user_name` varchar(255) DEFAULT '' COMMENT '用戶名稱',
`user_phone` varchar(50) DEFAULT '' COMMENT '用戶手機',
`address` varchar(255) DEFAULT '' COMMENT '住址',
`weight` int(3) NOT NULL DEFAULT '1' COMMENT '權重,大者優(yōu)先',
`created_at` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '創(chuàng)建時間',
`updated_at` datetime DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP COMMENT '更新時間',
PRIMARY KEY (`user_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
INSERT INTO `user` VALUES ('1196978513958141952', '測試1', '18826334748', '廣州市海珠區(qū)', '1', '2019-11-20 10:28:51', '2019-11-22 14:28:26');
INSERT INTO `user` VALUES ('1196978513958141953', '測試2', '18826274230', '廣州市天河區(qū)', '2', '2019-11-20 10:29:37', '2019-11-22 14:28:14');
INSERT INTO `user` VALUES ('1196978513958141954', '測試3', '18826273900', '廣州市天河區(qū)', '1', '2019-11-20 10:30:19', '2019-11-22 14:28:30');二、依賴
<dependencies>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid-spring-boot-starter</artifactId>
<version>1.1.10</version>
</dependency>
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>1.3.2</version>
</dependency>
<dependency>
<groupId>tk.mybatis</groupId>
<artifactId>mapper-spring-boot-starter</artifactId>
<version>2.1.5</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.16</version>
</dependency>
<!-- 動態(tài)數(shù)據(jù)源 所需依賴 ### start-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-jdbc</artifactId>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-aop</artifactId>
<scope>provided</scope>
</dependency>
<!-- 動態(tài)數(shù)據(jù)源 所需依賴 ### end-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.4</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
</dependencies>
三、application.yml配置主從數(shù)據(jù)源
server:
port: 8001
spring:
jackson:
date-format: yyyy-MM-dd HH:mm:ss
time-zone: GMT+8
datasource:
type: com.alibaba.druid.pool.DruidDataSource
driver-class-name: com.mysql.cj.jdbc.Driver
master:
url: jdbc:mysql://127.0.0.1:3307/user?serverTimezone=Asia/Shanghai&useUnicode=true&characterEncoding=UTF-8&autoReconnect=true&failOverReadOnly=false&useSSL=false&zeroDateTimeBehavior=convertToNull&allowMultiQueries=true
username: root
password:
slave:
url: jdbc:mysql://127.0.0.1:3308/user?serverTimezone=Asia/Shanghai&useUnicode=true&characterEncoding=UTF-8&autoReconnect=true&failOverReadOnly=false&useSSL=false&zeroDateTimeBehavior=convertToNull&allowMultiQueries=true
username: root
password:
四、Config配置
@Getter
public enum DynamicDataSourceEnum {
MASTER("master"),
SLAVE("slave");
private String dataSourceName;
DynamicDataSourceEnum(String dataSourceName) {
this.dataSourceName = dataSourceName;
}
}@Configuration
@MapperScan(basePackages = "com.xjt.proxy.mapper", sqlSessionTemplateRef = "sqlTemplate")
public class DataSourceConfig{
//主庫
@Bean
@ConfigurationProperties(prefix = "spring.datasource.master")
public DataSource masterDb(){
return DruidDataSourceBuilder.create().build();
}
//從庫
@Bean
@ConditionalOnProperty(prefix = "spring.datasource", name = "slave", matchIfMissing = true)
@ConfigurationProperties(prefix = "spring.datasource.slave")
public DataSource slaveDb() {
return DruidDataSourceBuilder.create().build();
}
//主從動態(tài)配置
@Bean
public DynamicDataSource dynamicDb(@Qualifier("masterDb") DataSource masterDataSource,
@Autowired(required = false) @Qualifier("slaveDb") DataSource slaveDataSource){
DynamicDataSource dynamicDataSource = new DynamicDataSource();
Map<Object,Object> targetDataSources = new HashMap<>();
targetDataSources.put(DynamicDataSourceEnum.MASTER.getDataSourceName(), masterDataSource);
if(slaveDataSource != null){
targetDataSources.put(DynamicDataSourceEnum.SLAVE.getDataSourceName(), slaveDataSource);
}
dynamicDataSource.setTargetDataSources(targetDataSources);
dynamicDataSource.setDefaultTargetDataSource(masterDataSource);
return dynamicDataSource;
}
@Bean
public SqlSessionFactory sessionFactory(){
SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
bean.setMapperLocations(
new PathMatchingResourcePatternResolver().getResources("classpath*:mapper/*Mapper.xml"));
bean.setDataSource(dynamicDataSource);
return bean.getObject();
}
@Bean
public SqlSessionTemplate sqlTemplate(){
return new SqlSessionTemplate(sqlSessionFactory);
}
@Bean(name = "dataourceTx")
public DataSourceTransactionManager dataSourceTx(){
DataSourceTransactionManager dataSourceTransactionManager = new DataSourceTransactionManager();
dataSourceTransactionManager.setDataSource(dynamicDataSource);
return dataSourceTransactionManager;
}
}五、設置路由
為了方便查找對應的數(shù)據(jù)源,我們可以用ThreadLocal保存數(shù)據(jù)源的信息到每個線程中,方便我們需要時獲取
pubic class DataSourceContextHolder{
private static final ThreadLocal<String> DYNAMIC_DATASOURCE_CONTEXT = new ThreadLocal<>();
public static void set(String datasourceType) {
DYNAMIC_DATASOURCE_CONTEXT.set(datasourceType);
}
public static String get() {
return DYNAMIC_DATASOURCE_CONTEXT.get();
}
public static void clear() {
DYNAMIC_DATASOURCE_CONTEXT.remove();
}
}AbstractRoutingDataSource的作用是基于查找key路由到對應的數(shù)據(jù)源,它內(nèi)部維護了一組目標數(shù)據(jù)源,并且做了路由key與目標數(shù)據(jù)源之間的映射,提供基于key查找數(shù)據(jù)源的方法。
public class DynamicDataSource extends AbstractRoutingDataSource {
@Override
protected Object determineCurrentLookupKey() {
return DataSourceContextHolder.get();
}
}六、數(shù)據(jù)源的注解
方便切換數(shù)據(jù)源,注解中包含數(shù)據(jù)源對應的枚舉值,默認是主庫
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.METHOD)
@Documented
public @interface DataSourceSelector {
DynamicDataSourceEnum value() default DynamicDataSourceEnum.MASTER;
boolean clear() default true;
}七、Aop切換數(shù)據(jù)源
定義一個aop類,對有注解的方法做切換數(shù)據(jù)源的操作
@Slf4j
@Aspect
@Order(value = 1)
@Component
public class DataSourceContextAop {
@Around("@annotation(com.xjt.proxy.dynamicdatasource.DataSourceSelector)")
public Object setDynamicDataSource(ProceedingJoinPoint pjp) throws Throwable {
boolean clear = true;
try {
Method method = this.getMethod(pjp);
DataSourceSelector dataSourceImport = method.getAnnotation(DataSourceSelector.class);//獲取注解標注的方法
clear = dataSourceImport.clear();
DataSourceContextHolder.set(dataSourceImport.value().getDataSourceName());
log.info("========數(shù)據(jù)源切換至:{}", dataSourceImport.value().getDataSourceName());
return pjp.proceed();
} finally {
if (clear) {
DataSourceContextHolder.clear();
}
}
}
private Method getMethod(JoinPoint pjp) {
MethodSignature signature = (MethodSignature)pjp.getSignature();
return signature.getMethod();
}
}八、測試
寫好Service文件,包含讀取和更新兩個方法
@Service
public class UserService {
@Autowired
private UserMapper userMapper;
@DataSourceSelector(value = DynamicDataSourceEnum.SLAVE)
public List<User> listUser() {
List<User> users = userMapper.selectAll();
return users;
}
@DataSourceSelector(value = DynamicDataSourceEnum.MASTER)
public int update() {
User user = new User();
user.setUserId(Long.parseLong("1196978513958141952"));
user.setUserName("修改后的名字2");
return userMapper.updateByPrimaryKeySelective(user);
}
@DataSourceSelector(value = DynamicDataSourceEnum.SLAVE)
public User find() {
User user = new User();
user.setUserId(Long.parseLong("1196978513958141952"));
return userMapper.selectByPrimaryKey(user);
}
}根據(jù)方法上的注解可以看出,讀的方法走從庫,更新的方法走主庫,更新的對象是userId為1196978513958141953 的數(shù)據(jù)
@RunWith(SpringRunner.class)
@SpringBootTest
class UserServiceTest {
@Autowired
UserService userService;
@Test
void listUser() {
List<User> users = userService.listUser();
for (User user : users) {
System.out.println(user.getUserId());
System.out.println(user.getUserName());
System.out.println(user.getUserPhone());
}
}
@Test
void update() {
userService.update();
User user = userService.find();
System.out.println(user.getUserName());
}
}讀取方法

更新方法

執(zhí)行之后,比對數(shù)據(jù)庫就可以發(fā)現(xiàn)主從庫都修改了數(shù)據(jù),說明我們的讀寫分離是成功的。當然,更新方法可以指向從庫,這樣一來就只會修改到從庫的數(shù)據(jù),而不會涉及到主庫。
到此這篇關于SpringBoot+aop實現(xiàn)主從數(shù)據(jù)庫的讀寫分離的文章就介紹到這了,更多相關SpringBoot主從數(shù)據(jù)庫的讀寫分離內(nèi)容請搜索腳本之家以前的文章或繼續(xù)瀏覽下面的相關文章希望大家以后多多支持腳本之家!
相關文章
深入探究Java中的HashMap為什么會產(chǎn)生死循環(huán)
HashMap?死循環(huán)發(fā)生在?JDK?1.8?之前的版本中,這篇文章主要來和大家深入探究一下為什么Java中HashMap會產(chǎn)生死循環(huán),感興趣的小伙伴可以了解一下2023-05-05
淺談springboot項目中定時任務如何優(yōu)雅退出
這篇文章主要介紹了淺談springboot項目中定時任務如何優(yōu)雅退出?具有很好的參考價值,希望對大家有所幫助。一起跟隨小編過來看看吧2020-09-09
Mybatis-Plus中的@TableName 和 table-prefix使用
table-prefix 是一個全局配置,它會自動在所有表名前添加指定的前綴,這個配置對于那些使用一致命名約定的數(shù)據(jù)庫表非常有用,這篇文章主要介紹了Mybatis-Plus中的@TableName 和 table-prefix使用,需要的朋友可以參考下2024-08-08

