MyBatis使用Zookeeper保存数据库的配置可动态刷新的实现代码

package com.cnscud.cavedemo.fundmain.config;

import com.cnscud.xpower.dbn.SimpleDBNDataSourceFactory;

import org.apache.ibatis.session.SqlSessionFactory;

import org.mybatis.spring.SqlSessionFactoryBean;

import org.mybatis.spring.SqlSessionTemplate;

import org.mybatis.spring.annotation.MapperScan;

import org.springframework.beans.factory.annotation.Qualifier;

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 org.springframework.jdbc.datasource.DataSourceTransactionManager;

import org.springframework.transaction.PlatformTransactionManager;

import javax.sql.DataSource;

/**

  * Database Config 多数据源配置: 主数据源.

  *

  * @author Felix Zhang 2021-08-02 17:30

  * @version 1.0.0

  */

@Configuration

@MapperScan (basePackages = { "com.cnscud.cavedemo.fundmain.dao" },

         sqlSessionFactoryRef = "sqlSessionFactoryMainDataSource" )

public class MainDataSourceConfig {

     //常规配置: 使用application.yml里面的配置.

     @Primary

     @Bean (name = "mainDataSource" )

     @ConfigurationProperties ( "spring.datasource.main" )

     public DataSource mainDataSource() throws Exception {

         return DataSourceBuilder.create().build();

     }

     @Primary

     @Bean (name = "sqlSessionFactoryMainDataSource" )

     public SqlSessionFactory sqlSessionFactoryMainDataSource( @Qualifier ( "mainDataSource" ) DataSource mainDataSource) throws Exception {

         SqlSessionFactoryBean factoryBean = new SqlSessionFactoryBean();

         //org.apache.ibatis.session.Configuration configuration = new org.apache.ibatis.session.Configuration();

         //configuration.setMapUnderscoreToCamelCase(true);

         //factoryBean.setConfiguration(configuration);

         factoryBean.setConfigLocation( new PathMatchingResourcePatternResolver().getResource( "classpath:mybatis-config.xml" ));

         // 使用mainDataSource数据源, 连接mainDataSource库

         factoryBean.setDataSource(mainDataSource);

         //下边两句仅仅用于*.xml文件，如果整个持久层操作不需要使用到xml文件的话（只用注解就可以搞定），则不加

         //指定entity和mapper xml的路径

         //factoryBean.setTypeAliasesPackage("com.cnscud.cavedemo.fundmain.model");

         factoryBean.setMapperLocations( new PathMatchingResourcePatternResolver().getResources( "classpath:com/cnscud/cavedemo/fundmain/mapper/*.xml" ));

         return factoryBean.getObject();

     }

     @Primary

     @Bean

     public SqlSessionTemplate sqlSessionTemplateMainDataSource( @Qualifier ( "sqlSessionFactoryMainDataSource" ) SqlSessionFactory sqlSessionTemplateMainDataSource) throws Exception {

         //使用注解中配置的Factory

         return new SqlSessionTemplate(sqlSessionTemplateMainDataSource);

     }

     @Primary

     @Bean

     public PlatformTransactionManager mainTransactionManager( @Qualifier ( "mainDataSource" ) DataSource prodDataSource) {

         return new DataSourceTransactionManager(prodDataSource);

     }

}

package com.cnscud.xpower.dbn;

import javax.sql.DataSource;

import java.io.PrintWriter;

import java.sql.Connection;

import java.sql.SQLException;

import java.sql.SQLFeatureNotSupportedException;

import java.util.logging.Logger;

/**

  * Datasource wrapper, 为了方便动态创建DataSource.

  *

  * @author Felix Zhang 2021-08-05 14:14

  * @version 1.0.0

  */

public class DynamicBy Zookeeper DataSourceWrapper implements DataSource {

     protected SimpleDBNConnectionPool simpleDBNConnectionPool;

     protected String bizName;

     public DynamicByZookeeperDataSourceWrapper(SimpleDBNConnectionPool simpleDBNConnectionPool, String bizName) {

         this .simpleDBNConnectionPool = simpleDBNConnectionPool;

         this .bizName = bizName;

     }

     protected DataSource pickDataSource() throws SQLException{

         return simpleDBNConnectionPool.getDataSource(bizName);

     }

     @Override

     public Connection getConnection() throws SQLException {

         return pickDataSource().getConnection();

     }

     @Override

     public Connection getConnection(String username, String password) throws SQLException {

         return pickDataSource().getConnection(username, password);

     }

     @Override

     public <T> T unwrap(Class<T> iface) throws SQLException {

         return pickDataSource().unwrap(iface);

     }

     @Override

     public boolean isWrapperFor(Class<?> iface) throws SQLException {

         return pickDataSource().isWrapperFor(iface);

     }

     @Override

     public PrintWriter getLogWriter() throws SQLException {

         return pickDataSource().getLogWriter();

     }

     @Override

     public void setLogWriter(PrintWriter out) throws SQLException {

         pickDataSource().setLogWriter(out);

     }

     @Override

     public void setLoginTimeout( int seconds) throws SQLException {

         pickDataSource().setLoginTimeout(seconds);

     }

     @Override

     public int getLoginTimeout() throws SQLException {

         return pickDataSource().getLoginTimeout();

     }

     @Override

     public Logger getParentLogger() throws SQLFeatureNotSupportedException {

         throw new SQLFeatureNotSupportedException();

     }

}

package com.cnscud.xpower.dbn;

import com.github.zkclient.IZkDataListener;

import com.zaxxer.hikari.HikariDataSource;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

import javax.sql.DataSource;

import java.sql.Connection;

import java.sql.SQLException;

import java.util.HashSet;

import java.util.Map;

import java.util.Set;

import java.util.concurrent.ConcurrentHashMap;

import static java.lang.String.format;

/**

  * The simple datasource pool.

  *

  * 根据名字存放多个数据库的DataSource, 并且会监听Zookeeper配置, 动态重建.

  *

  * @author adyliu (imxylz@gmail测试数据)

  * @since 2011-7-27

  */

public class SimpleDBNConnectionPool {

     final Logger logger = LoggerFactory.getLogger(getClass());

     private Map<String, DataSource> instances = new ConcurrentHashMap<>();

     private final Set<String> watcherSchema = new HashSet<String>();

     public DataSource getInstance(String bizName) {

         try {

             return findDbInstance(bizName);

         }

         catch (SQLException e) {

             e.printStackTrace();

         }

         return null ;

     }

     public Connection getConnection(String bizName) throws SQLException {

         DataSource ds = getDataSource(bizName);

         return ds.getConnection();

     }

     public DataSource getDataSource(String bizName) throws SQLException {

         return findDbInstance(bizName);

     }

     protected void destroyInstance( final String bizName) {

         synchronized (instances) {

             DataSource oldInstanceIf = instances.remove(bizName);

             logger.warn(format( "destoryInstance %s and %s" , bizName, oldInstanceIf != null ? "close datasource" : "do nothing" ));

             if (oldInstanceIf != null ) {

                 closeDataSource(oldInstanceIf);

             }

         }

     }

     protected void closeDataSource(DataSource ds) {

         if (ds instanceof HikariDataSource) {

             try {

                 ((HikariDataSource) ds).close();

             }

             catch (Exception e) {

                 logger.error( "Close datasource failed. " , e);

             }

         }

     }

     private DataSource createInstance(Map<String, String> dbcfg) {

         return new SimpleDataSourceBuilder().buildDataSource(dbcfg);

     }

     private DataSource findDbInstance( final String bizName) throws SQLException {

         DataSource ins = instances.get(bizName);

         if (ins != null ) {

             return ins;

         }

         synchronized (instances) { // 同步操作

             ins = instances.get(bizName);

             if (ins != null ) {

                 return ins;

             }

             boolean success = false ;

             try {

                 Map<String, String> dbcfg = SchemeNodeHelper.getInstance(bizName);

                 if (dbcfg == null ) {

                     throw new SQLException( "No such datasouce: " + bizName);

                 }

                 ins = createInstance(dbcfg);

                 //log.warn("ins put "+ins);

                 instances.put(bizName, ins);

                 if (watcherSchema.add(bizName)) {

                     SchemeNodeHelper.watchInstance(bizName, new IZkDataListener() {

                         public void handleDataDeleted(String dataPath) throws Exception {

                             logger.warn(dataPath + " was deleted, so destroy the bizName " + bizName);

                             destroyInstance(bizName);

                         }

                         public void handleDataChange(String dataPath, byte [] data) throws Exception {

                             logger.warn(dataPath + " was changed, so destroy the bizName " + bizName);

                             destroyInstance(bizName);

                         }

                     });

                 }

                 success = true ;

             }

             catch (SQLException e) {

                 throw e;

             }

             catch (Throwable t) {

                 throw new SQLException( "cannot build datasource for bizName: " + bizName, t);

             }

             finally {

                 if (!success) {

                     instances.remove(bizName);

                 }

             }

         }

         return ins;

     }

}

package com.cnscud.xpower.dbn;

import com.zaxxer.hikari.HikariConfig;

import com.zaxxer.hikari.HikariDataSource;

import org.apache测试数据mons.lang.StringUtils;

import java.util.Map;

/**

  * Hikari DataSource.

  *

  * 思考: 可以根据参数里面的类型来使用不同的库创建DataSource, 例如Druid. (默认为HikariDataSource)

  *

  *

  * @author Felix Zhang 2021-08-05 11:14

  * @version 1.0.0

  */

public class SimpleDataSourceBuilder {

     public HikariDataSource buildDataSource(Map<String, String> args) {

         HikariConfig config = new HikariConfig();

         config.setJdbcUrl(getUrl(args));

         config.setUsername(args.get( "username" ));

         config.setPassword(args.get( "password" ));

         config.setDriverClassName(getDriverClassName(args));

         String maximumPoolSizeKey = "maximum-pool-size" ;

         int maximumPoolSize = 30 ;

         if (StringUtils.isNotEmpty(args.get(maximumPoolSizeKey))){

             maximumPoolSize = Integer.parseInt(args.get(maximumPoolSizeKey));

         }

         config.addDataSourceProperty( "cachePrepStmts" , "true" ); //是否自定义配置，为true时下面两个参数才生效

         config.addDataSourceProperty( "prepStmtCacheSize" , maximumPoolSize); //连接池大小默认25，官方推荐250-500

         config.addDataSourceProperty( "prepStmtCacheSqlLimit" , "2048" ); //单条语句最大长度默认256，官方推荐2048

         config.addDataSourceProperty( "useServerPrepStmts" , "true" ); //新版本MySQL支持服务器端准备，开启能够得到显著性能提升

         config.addDataSourceProperty( "useLocalSessionState" , "true" );

         config.addDataSourceProperty( "useLocalTransactionState" , "true" );

         config.addDataSourceProperty( "rewriteBatchedStatements" , "true" );

         config.addDataSourceProperty( "cacheResultSetMetadata" , "true" );

         config.addDataSourceProperty( "cacheServerConfiguration" , "true" );

         config.addDataSourceProperty( "elideSetAutoCommits" , "true" );

         config.addDataSourceProperty( "maintainTimeStats" , "false" );

         config.setMaximumPoolSize(maximumPoolSize); //

         config.setMinimumIdle( 10 ); //最小闲置连接数，默认为0

         config.setMaxLifetime( 600000 ); //最大生存时间

         config.setConnectionTimeout( 30000 ); //超时时间30秒

         config.setIdleTimeout( 60000 );

         config.setConnectionTestQuery( "select 1" );

         return new HikariDataSource(config);

     }

     private String getDriverClassName(Map<String, String> args) {

         return args.get( "driver-class-name" );

     }

     private String getUrl(Map<String, String> args) {

         return args.get( "jdbc-url" ) == null ? args.get( "url" ): args.get( "jdbc-url" );

     }

}

package com.cnscud.xpower.dbn;

import com.cnscud.xpower.configcenter.ConfigCenter;

import com.cnscud.xpower.utils.Jsons;

import com.github.zkclient.IZkDataListener;

import org.apache测试数据mons.lang.StringUtils;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

import java.io.IOException;

import java.io.StringReader;

import java.util.HashMap;

import java.util.Map;

import java.util.Properties;

/**

  * 从Zookeeper的 /xpower/dbn节点下读取数据库配置.

  * 内容支持两种格式: json或者properties格式.

  *

  * JSON格式如下:

  * {

  *   "jdbc-url": "jdbc:mysql://127.0.0.1:3306/cavedemo?useUnicode=true&characterEncoding=utf8&useSSL=false&serverTimezone=UTC",

  *   "username": "dbuser",

  *   "password": "yourpassword",

  *   "driver-class-name": "com.mysql.cj.jdbc.Driver"

  * }

  *

  * Properties格式如下:

  *  jdbc-url: jdbc:mysql://127.0.0.1:3306/cavedemo?useUnicode=true&characterEncoding=utf8&useSSL=false&serverTimezone=UTC

  *  username: dbuser

  *  password: password

  *  driver-class-name: com.mysql.cj.jdbc.Driver

  *

  * @author Felix Zhang

  * @since 2021-8-5

  */

public class SchemeNodeHelper {

     static final Logger logger = LoggerFactory.getLogger(SchemeNodeHelper. class );

     //支持两种格式: json, properties

     public static Map<String, String> getInstance( final String instanceName) throws Exception {

         String data = ConfigCenter.getInstance().getDataAsString( "/xpower/dbn/" + instanceName);

         if (StringUtils.isEmpty(data)){

             return null ;

         }

         data = data.trim();

         if (data.startsWith( "{" )) {

             //as json

             Map<String, String> swap = Jsons.fromJson(data, Map. class );

             Map<String, String> result = new HashMap<>();

             if (swap != null ) {

                 for (String name : swap.keySet()) {

                     result.put(name.toLowerCase(), swap.get(name));

                 }

             }

             return result;

         }

         else {

             //as properties

             Properties props = new Properties();

             try {

                 props.load( new StringReader(data));

             }

             catch (IOException e) {

                 logger.error( "loading global config failed" , e);

             }

             Map<String, String> result = new HashMap<>();

             for (String name : props.stringPropertyNames()) {

                 result.put(name.toLowerCase(), props.getProperty(name));

             }

             return result;

         }

     }

     public static void watchInstance( final String bizName, final IZkDataListener listener) {

         final String path = "/xpower/dbn/" + bizName;

         ConfigCenter.getInstance().subscribeDataChanges(path, listener);

     }

}

/**

      * 添加@Primary注解，设置默认数据源，事务管理器.

      * 此处使用了一个可以动态重建的DataSource, 如果Zookeeper配置改变,会动态重建.

      */

     @Primary

     @Bean (name = "mainDataSource" )

     public DataSource mainDataSource() throws Exception {

         return SimpleDBNDataSourceFactory.getInstance().getDataSource( "cavedemo" );

     }