jdk環境:1.8
springboot:2.1.3.RELEASE
mybatisplus:3.2.0
本文主要用atomikos的AtomikosNonXADataSourceBean配置連接池,另一個是AtomikosDataSourceBean,是支持第三方如druid配置管理連接池,具體實現請參考我的另一篇文章:超簡單 springboot+ mybatisplus+druid 實現多數據源+分佈式事務
1、maven
<dependency>
<groupId>com.baomidou</groupId>
<artifactId>mybatis-plus-boot-starter</artifactId>
<version>3.2.0</version>
</dependency>
<!--分佈式事務-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-jta-atomikos</artifactId>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-aop</artifactId>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-configuration-processor</artifactId>
<optional>true</optional>
</dependency>
2、新建DataSourceContextHolder.java 提供設置、獲取、清除當前數據源的方法;
public class DataSourceContextHolder {
private static final ThreadLocal<String> contextHolder = new InheritableThreadLocal<>();
/**
* 設置數據源
*
* @param db
*/
public static void setDataSource(String db) {
contextHolder.set(db);
}
/**
* 取得當前數據源
*
* @return
*/
public static String getDataSource() {
return contextHolder.get();
}
/**
* 清除上下文數據
*/
public static void clear() {
contextHolder.remove();
}
}
3、DataSource.java 數據源註解 及DataSourceKeyEnum.java 數據源枚舉類;並提供獲取枚舉的方法
import java.lang.annotation.*;
@Target({ElementType.METHOD, ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface DataSource {
DataSourceKeyEnum value();
}
import lombok.Getter;
import org.apache.commons.lang3.StringUtils;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
public enum DataSourceKeyEnum {
MASTER("master"),
/**
* 表示 所有的SLAVE, 隨機選擇一個SLAVE0, 或者SLAVE1
*/
SLAVE("slave"),
SLAVE0("slave0"),
SLAVE1("slave1"),;
@Getter
private String value;
DataSourceKeyEnum(String value) {
this.value = value;
}
public static List<DataSourceKeyEnum> getSlaveList() {
return Arrays.asList(SLAVE0, SLAVE1);
}
/**
* 根據註解獲取數據源
*
* @param dataSource
* @return
*/
public static DataSourceKeyEnum getDataSourceKey(DataSource dataSource) {
if (dataSource == null) {
return MASTER;
}
if (dataSource.value() == DataSourceKeyEnum.SLAVE) {
List<DataSourceKeyEnum> dataSourceKeyList = DataSourceKeyEnum.getSlaveList();
// FIXME 目前亂序
Collections.shuffle(dataSourceKeyList);
return dataSourceKeyList.get(0);
} else {
return dataSource.value();
}
}
}
4、DataSourceAspect.java 數據源切面類,這裏是只做了對mapper層攔截,包括攔截了mybatisplus的公共BaseMapper
import lombok.extern.slf4j.Slf4j;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Pointcut;
import org.aspectj.lang.reflect.MethodSignature;
import org.springframework.aop.support.AopUtils;
import org.springframework.context.annotation.Lazy;
import org.springframework.core.annotation.Order;
import org.springframework.stereotype.Component;
import org.springframework.core.annotation.AnnotationUtils;
import java.lang.reflect.Method;
import java.lang.reflect.Type;
@Component
@Slf4j
@Aspect
@Order(-1)
public class DataSourceAspect {
@Pointcut("execution(* com.admin.*.dao.*Mapper.*(..))||execution(* com.baomidou.mybatisplus.core.mapper.*Mapper.*(..)))")
public void pointCut() {
}
@Around("pointCut()")
public Object doBefore(ProceedingJoinPoint pjp) throws Throwable {
MethodSignature signature = (MethodSignature) pjp.getSignature();
Method method = signature.getMethod();
DataSource dataSource = AnnotationUtils.findAnnotation(method, DataSource.class);
DataSourceKeyEnum keyEnum = DataSourceKeyEnum.getDataSourceKey(dataSource);
log.info("選擇的數據源:"+keyEnum.getValue());
DataSourceContextHolder.setDataSource(keyEnum.getValue());
Object o=pjp.proceed();
DataSourceContextHolder.clear();
return o;
}
@Pointcut("execution(* com.baomidou.mybatisplus.extension.service.IService.*Batch*(..)))")
public void pointCutBatch() {
}
//對mybatisplus批量操作切面
@Around("pointCutBatch()")
public Object doBeforeBatch(ProceedingJoinPoint pjp) throws Throwable {
DataSourceContextHolder.setDataSource(DataSourceKeyEnum.MASTER.getValue());
Object o = pjp.proceed();
DataSourceContextHolder.clear();
return o;
}
}
5、application.yml 相關配置
spring:
datasource:
atomikos:
master:
url: jdbc:mysql://127.0.0.1:3306/test?charset=utf8mb4&useUnicode=true&characterEncoding=utf8&useSSL=false&autoReconnect=true&serverTimezone=Asia/Shanghai
user: root
password: 123456
uniqueResourceName: master
slave0:
url: jdbc:mysql://127.0.0.1:3306/test?charset=utf8mb4&useUnicode=true&characterEncoding=utf8&useSSL=false&autoReconnect=true&serverTimezone=Asia/Shanghai
user: root
password: 123456
uniqueResourceName: slave0
slave1:
url: jdbc:mysql://127.0.0.1:3306/test?charset=utf8mb4&useUnicode=true&characterEncoding=utf8&useSSL=false&autoReconnect=true&serverTimezone=Asia/Shanghai
user: root
password: 123456
uniqueResourceName: slave1
jta:
atomikos:
properties:
log-base-dir: ../logs
transaction-manager-id: txManager #默認取計算機的IP地址 需保證生產環境值唯一
6、複製SqlSessionTemplate.java裏所有代碼新建到MySqlSessionTemplate.java然後繼承SqlSessionTemplate.java,並按照下方替換相應的方法(只貼出了更改了的地方)完整MySqlSessionTemplate.java 點擊下載
import lombok.Getter;
import lombok.Setter;
public class MySqlSessionTemplate extends SqlSessionTemplate {
@Getter
@Setter
private Map<String, SqlSessionFactory> targetSqlSessionFactories;
@Getter
@Setter
private SqlSessionFactory defaultTargetSqlSessionFactory;
public MySqlSessionTemplate(SqlSessionFactory sqlSessionFactory, ExecutorType executorType,
PersistenceExceptionTranslator exceptionTranslator) {
super(sqlSessionFactory, executorType, exceptionTranslator);
notNull(sqlSessionFactory, "Property 'sqlSessionFactory' is required");
notNull(executorType, "Property 'executorType' is required");
this.sqlSessionFactory = sqlSessionFactory;
this.executorType = executorType;
this.exceptionTranslator = exceptionTranslator;
this.sqlSessionProxy = (SqlSession) newProxyInstance(SqlSessionFactory.class.getClassLoader(),
new Class[]{SqlSession.class}, new MySqlSessionTemplate.SqlSessionInterceptor());
this.defaultTargetSqlSessionFactory = sqlSessionFactory;
}
//TODO 主要修改了這一塊,並且用到sqlSessionFactory的地方都改調用該方法獲取
public SqlSessionFactory getSqlSessionFactory() {
SqlSessionFactory targetSqlSessionFactory = targetSqlSessionFactories.get(DataSourceContextHolder.getDataSource());
if (targetSqlSessionFactory != null) {
return targetSqlSessionFactory;
} else if (defaultTargetSqlSessionFactory != null) {
return defaultTargetSqlSessionFactory;
} else {
Assert.notNull(targetSqlSessionFactories, "Property 'targetSqlSessionFactories' or 'defaultTargetSqlSessionFactory' are required");
}
return this.sqlSessionFactory;
}
/**
* {@inheritDoc}
*/
@Override
public Configuration getConfiguration() {
return this.getSqlSessionFactory().getConfiguration();
}
private class SqlSessionInterceptor implements InvocationHandler {
@Override
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
SqlSession sqlSession = getSqlSession(MySqlSessionTemplate.this.getSqlSessionFactory(),
MySqlSessionTemplate.this.executorType, MySqlSessionTemplate.this.exceptionTranslator);
try {
Object result = method.invoke(sqlSession, args);
if (!isSqlSessionTransactional(sqlSession, MySqlSessionTemplate.this.getSqlSessionFactory())) {
// force commit even on non-dirty sessions because some databases require
// a commit/rollback before calling close()
sqlSession.commit(true);
}
return result;
} catch (Throwable t) {
Throwable unwrapped = unwrapThrowable(t);
if (MySqlSessionTemplate.this.exceptionTranslator != null && unwrapped instanceof PersistenceException) {
// release the connection to avoid a deadlock if the translator is no loaded. See issue #22
closeSqlSession(sqlSession, MySqlSessionTemplate.this.sqlSessionFactory);
sqlSession = null;
Throwable translated = MySqlSessionTemplate.this.exceptionTranslator
.translateExceptionIfPossible((PersistenceException) unwrapped);
if (translated != null) {
unwrapped = translated;
}
}
throw unwrapped;
} finally {
if (sqlSession != null) {
closeSqlSession(sqlSession, MySqlSessionTemplate.this.getSqlSessionFactory());
}
}
}
}
}
7、新建MyGlobalConfig.java並繼承GlobalConfig,主要重寫mybaitsplus自帶的GlobalConfig的getSqlSessionFactory方法;
不重寫該類會導致後面mybatisplus自帶的saveBatch等批量操作方法無法切換數據源
import com.baomidou.mybatisplus.core.config.GlobalConfig;
import com.admin.common.datasource.MySqlSessionTemplate;
import org.apache.ibatis.session.SqlSessionFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import javax.annotation.PostConstruct;
@Component
public class MyGlobalConfig extends GlobalConfig {
@Autowired
private MySqlSessionTemplate sqlSessionTemplate;
private static MySqlSessionTemplate mySqlSessionTemplate;
@Override
public SqlSessionFactory getSqlSessionFactory() {
return mySqlSessionTemplate.getSqlSessionFactory();
}
@PostConstruct
public void init() {
MyGlobalConfig.mySqlSessionTemplate = sqlSessionTemplate;
}
}
8、新建MyBatisPlusConfiguration.java,mybatisplus配置 和多數據源配置
import com.alibaba.druid.pool.xa.DruidXADataSource;
import com.atomikos.jdbc.nonxa.AtomikosNonXADataSourceBean;
import com.baomidou.mybatisplus.autoconfigure.SpringBootVFS;
import com.baomidou.mybatisplus.core.MybatisConfiguration;
import com.baomidou.mybatisplus.core.parser.ISqlParser;
import com.baomidou.mybatisplus.extension.plugins.PaginationInterceptor;
import com.baomidou.mybatisplus.extension.plugins.tenant.TenantHandler;
import com.baomidou.mybatisplus.extension.plugins.tenant.TenantSqlParser;
import com.baomidou.mybatisplus.extension.spring.MybatisSqlSessionFactoryBean;
import com.admin.util.datasource.DataSourceKeyEnum;
import net.sf.jsqlparser.expression.Expression;
import net.sf.jsqlparser.expression.LongValue;
import org.apache.ibatis.mapping.BoundSql;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.type.JdbcType;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.jdbc.DataSourceBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
@Configuration
@MapperScan(basePackages = {"com.admin.*.dao", "com.baomidou.mybatisplus.samples.quickstart.mapper"}, sqlSessionTemplateRef = "sqlSessionTemplate")
public class MyBatisPlusConfiguration {
@Bean
@Primary //多數據源時需要加上該註解,加一個即可
@ConfigurationProperties(prefix = "spring.datasource.atomikos.master")
public AtomikosNonXADataSourceBean userMaster() {
//也可以直接return new AtomikosNonXADataSourceBean();
return DataSourceBuilder.create().type(AtomikosNonXADataSourceBean.class).build();
}
@Bean
@ConfigurationProperties(prefix = "spring.datasource.atomikos.slave0")
public AtomikosNonXADataSourceBean userSlave0() {
return DataSourceBuilder.create().type(AtomikosNonXADataSourceBean.class).build();
}
@Bean
@ConfigurationProperties(prefix = "spring.datasource.atomikos.slave1")
public AtomikosNonXADataSourceBean userSlave1() {
return DataSourceBuilder.create().type(AtomikosNonXADataSourceBean.class).build();
}
@Bean(name = "sqlSessionTemplate")
public MySqlSessionTemplate customSqlSessionTemplate() throws Exception {
Map<String, SqlSessionFactory> sqlSessionFactoryMap = new HashMap<String, SqlSessionFactory>() {{
put(DataSourceKeyEnum.MASTER.getValue(), createSqlSessionFactory(userMaster()));
put(DataSourceKeyEnum.SLAVE0.getValue(), createSqlSessionFactory(userSlave0()));
put(DataSourceKeyEnum.SLAVE1.getValue(), createSqlSessionFactory(userSlave1()));
}};
MySqlSessionTemplate sqlSessionTemplate = new MySqlSessionTemplate(sqlSessionFactoryMap.get(DataSourceKeyEnum.MASTER.getValue()));
sqlSessionTemplate.setTargetSqlSessionFactories(sqlSessionFactoryMap);
return sqlSessionTemplate;
}
/**
* 創建數據源
*
* @param dataSource
* @return
*/
private SqlSessionFactory createSqlSessionFactory(AtomikosNonXADataSourceBean dataSource) throws Exception {
dataSource.setMaxPoolSize(10);
dataSource.setMinPoolSize(2);
dataSource.setPoolSize(2);
dataSource.setDriverClassName("com.mysql.cj.jdbc.Driver");
dataSource.setMaxIdleTime(60);//最大閒置時間,超過最小連接池的連接將關閉
dataSource.setMaxLifetime(1200);//連接最大閒置時間 單位s 全部的連接超時將關閉
dataSource.setTestQuery(druidDataSource.getValidationQuery());//前期先每次請求前都執行該操作保證連接有效,後期可用定時任務執行
dataSource.setMaintenanceInterval(60);//定時維護線程週期 單位秒
//以上配置可提取到.yml內通過ConfigurationProperties註解注入
dataSource.init();//項目啓動則初始化連接
MybatisSqlSessionFactoryBean sqlSessionFactory = new MybatisSqlSessionFactoryBean();
sqlSessionFactory.setDataSource(dataSource);
sqlSessionFactory.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath*:/com/admin/*/dao/xml/*.xml"));
sqlSessionFactory.setVfs(SpringBootVFS.class);
MybatisConfiguration configuration = new MybatisConfiguration();
//configuration.setDefaultScriptingLanguage(MybatisXMLLanguageDriver.class);
configuration.setJdbcTypeForNull(JdbcType.NULL);
configuration.setMapUnderscoreToCamelCase(false);
configuration.setCacheEnabled(false);
sqlSessionFactory.setConfiguration(configuration);
sqlSessionFactory.setPlugins(paginationInterceptor());
//重寫了GlobalConfig的MyGlobalConfig注入到sqlSessionFactory使其生效
MyGlobalConfig globalConfig = new MyGlobalConfig();
sqlSessionFactory.setGlobalConfig(globalConfig);
sqlSessionFactory.afterPropertiesSet();
return sqlSessionFactory.getObject();
}
/*
* 自定義的分頁插件,自動識別數據庫類型
*/
@Bean
public PaginationInterceptor paginationInterceptor() {
return new PaginationInterceptor();
}
}
如需druid監控加上以下配置並引入druid相關jar包即可(此方法只能監控除sql以外的。如需監控sql,具體實現請參考我的另一篇文章:超簡單 springboot+ mybatisplus+druid 實現多數據源+分佈式事務)
spring:
datasource:
druid:
web-stat-filter:
enabled: true
url-pattern: /*
exclusions: /druid/*,*.js,*.gif,*.jpg,*.bmp,*.png,*.css,*.ico
session-stat-enable: true
session-stat-max-count: 10
stat-view-servlet:
enabled: true
url-pattern: /druid/*
reset-enable: true
login-username: admin
login-password: admin
aop-patterns: com.admin.*.service.*
事務使用方法如單數據源一樣:對應的方法或類上加@Transactional註解即可
遇到的坑:
1、設置maintenanceInterval和maxLifetime後,當maxLifetime大於1800秒左右,程序的連接顯示已回收,而mysql連接依然還在,最終程序重複創建新連接(以爲舊連接已關閉)導致mysql連接數滿了。建議設置在1800秒以內;