Springboot+druid多數據（三）

Base項目創建完成後需要集成數據庫，能夠做到連接多數據庫且能夠切換到指定數據庫。

這個就用到了AbstractRoutingDataSource

連接池使用的是druid

<dependency>
	<groupId>com.alibaba</groupId>
	<artifactId>druid</artifactId>
	<version>1.1.8</version>
</dependency>

數據庫使用的是postgresql

<dependency>
	<groupId>org.postgresql</groupId>
	<artifactId>postgresql</artifactId>
</dependency>

其他引用查看 點擊打開鏈接

1.resources下新建application-dev.properties文件。
2.application.properties 裏面新增內容 spring.profiles.active=dev 這樣我們可以將不同的環境配置文件區分開。

3.application-dev.properties內新增一下數據源配置信息。

#應用訪問名稱
server.servlet.contextPath=/control
server.port=8088
#serviceNode是自定義,用於區分不同的服務節點,暫時可不關注
server.serviceNode=control

# 數據庫訪問配置
spring.datasource.type=com.alibaba.druid.pool.DruidDataSource
spring.datasource.filters=stat
spring.datasource.logSlowSql=false
spring.hibernate.dialect=org.hibernate.dialect.PostgreSQL9Dialect
spring.hibernate.hbm2ddl.auto=none
spring.hibernate.show_sql=false
string.hibernate.format_sql=false 

#postgresql master爲主數據源，也是默認數據源
spring.datasource.master.url=jdbc:postgresql://127.0.0.1:5432/control?currentSchema=control
spring.datasource.master.username=root  
spring.datasource.master.password=root  
spring.datasource.master.driverClassName=org.postgresql.Driver
spring.datasource.master.initialSize=5
spring.datasource.master.minIdle=5
spring.datasource.master.maxActive=20
spring.datasource.master.maxWait=60000
spring.datasource.master.timeBetweenEvictionRunsMillis=60000
spring.datasource.master.minEvictableIdleTimeMillis=300000
spring.datasource.master.testWhileIdle=true
spring.datasource.master.testOnBorrow=false
spring.datasource.master.testOnReturn=false
spring.datasource.master.filters=stat

#nodes爲不同的數據源節點格式爲:node1,node2,node3,……
spring.datasource.nodes=node1
spring.datasource.node1.url=jdbc:postgresql://127.0.0.1:5432/ccs?currentSchema=ccs
spring.datasource.node1.username=root  
spring.datasource.node1.password=root  
spring.datasource.node1.driverClassName=org.postgresql.Driver
spring.datasource.node1.initialSize=5
spring.datasource.node1.minIdle=5
spring.datasource.node1.maxActive=20
spring.datasource.node1.maxWait=60000
spring.datasource.node1.timeBetweenEvictionRunsMillis=60000
spring.datasource.node1.minEvictableIdleTimeMillis=300000
#spring.datasource.node1.validationQuery=SELECT 1 FROM DUAL
spring.datasource.node1.testWhileIdle=true
spring.datasource.node1.testOnBorrow=false
spring.datasource.node1.testOnReturn=false
spring.datasource.node1.filters=stat

4.數據源配置文件創建完成後需要初始化數據源,創建不同的DataSource Bean
以下是初始化全過程：

package com.cloud.base.server.config;

import java.util.HashMap;
import java.util.Map;
import org.apache.commons.lang.StringUtils;
import org.hibernate.jpa.HibernatePersistenceProvider;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.beans.factory.support.BeanDefinitionBuilder;
import org.springframework.beans.factory.support.DefaultListableBeanFactory;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.jdbc.DataSourceBuilder;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.boot.web.servlet.ServletRegistrationBean;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.env.Environment;
import org.springframework.orm.jpa.JpaTransactionManager;
import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
import org.springframework.transaction.PlatformTransactionManager;
import com.alibaba.druid.pool.DruidDataSource;
import com.alibaba.druid.support.http.StatViewServlet;
import com.alibaba.druid.support.http.WebStatFilter;

@Configuration
public class DruidConfig implements ApplicationContextAware {

	@Autowired
	private Environment env;

	@Value("${spring.datasource.type}")
	private Class<? extends DruidDataSource> dataSourceType;

	@Value("${spring.datasource.logSlowSql}")
	private String logSlowSql;

	@Value("${spring.hibernate.dialect}")
	private String dialect;

	@Value("${spring.hibernate.hbm2ddl.auto}")
	private String hbm2ddl;
	
	@Value("${spring.hibernate.show_sql}")
	private String show_sql;
	
	@Value("${string.hibernate.format_sql}")
	private String format_sql;

	@Value("${spring.datasource.nodes}")
	private String nodes;

	private ConfigurableApplicationContext app;  
	
	@Bean(name = "masterDataSource", destroyMethod = "close", initMethod = "init")
	@ConfigurationProperties(prefix = "spring.datasource.master")
	public DruidDataSource masterDataSource() {
		return DataSourceBuilder.create().type(dataSourceType).build();
	}

	@Bean(name = "dataSource")
	public DynamicDataSource dataSource() {
		ApplicationConfig.serviceNode = env.getProperty("server.serviceNode");
		DefaultListableBeanFactory acf = (DefaultListableBeanFactory) app.getAutowireCapableBeanFactory();  
		BeanDefinitionBuilder bdb;
		DynamicDataSource dynamicDataSource = new DynamicDataSource();
		Map<Object, Object> targetDataSources = new HashMap<>();
		targetDataSources.put("master", masterDataSource());
		DynamicDataSourceContextHolder.dataSourceIds.add("master");
		if (!StringUtils.isEmpty(nodes)) {
			for (int i = 0; i < nodes.split(",").length; i++) {
				String beanKey = nodes.split(",")[i];
				final String prefix = "spring.datasource." + beanKey;

		        bdb = BeanDefinitionBuilder.rootBeanDefinition(DruidDataSource.class);  
		        bdb.setDestroyMethodName("close");
		        bdb.setInitMethodName("init");
		        bdb.getBeanDefinition().setAttribute("id", beanKey);  
		        bdb.addPropertyValue("driverClassName", env.getProperty(prefix + ".driverClassName"));  
		        bdb.addPropertyValue("url", env.getProperty(prefix + ".url"));  
		        bdb.addPropertyValue("username", env.getProperty(prefix + ".username"));  
		        bdb.addPropertyValue("password", env.getProperty(prefix + ".password"));  
		        bdb.addPropertyValue("initialSize", env.getProperty(prefix + ".initialSize"));  
		        bdb.addPropertyValue("minIdle", env.getProperty(prefix + ".minIdle"));  
		        bdb.addPropertyValue("maxActive", env.getProperty(prefix + ".maxActive"));  
		        bdb.addPropertyValue("maxWait", env.getProperty(prefix + ".maxWait"));  
		        bdb.addPropertyValue("timeBetweenEvictionRunsMillis", env.getProperty(prefix + ".minEvictableIdleTimeMillis"));  
		        bdb.addPropertyValue("minEvictableIdleTimeMillis", env.getProperty(prefix + ".minEvictableIdleTimeMillis"));  
		        bdb.addPropertyValue("validationQuery", env.getProperty(prefix + ".validationQuery"));  
		        bdb.addPropertyValue("testWhileIdle", env.getProperty(prefix + ".testWhileIdle"));  
		        bdb.addPropertyValue("testOnBorrow", env.getProperty(prefix + ".testOnBorrow"));  
		        bdb.addPropertyValue("testOnReturn", env.getProperty(prefix + ".testOnReturn"));  
		        bdb.addPropertyValue("filters", env.getProperty(prefix + ".filters"));  

                        /** 以node名稱爲Bean的ID 注入到Spring*/
		        acf.registerBeanDefinition(beanKey, bdb.getBeanDefinition());   
				
		        targetDataSources.put(beanKey, app.getBean(beanKey)); 
				DynamicDataSourceContextHolder.dataSourceIds.add(beanKey);
			}
		}
		
		dynamicDataSource.setTargetDataSources(targetDataSources);

                /** 設置master爲默認數據源*/
		dynamicDataSource.setDefaultTargetDataSource(masterDataSource());
		dynamicDataSource.afterPropertiesSet();  
		
		return dynamicDataSource;
	}

	@Bean
	public ServletRegistrationBean druidServlet() {
		ServletRegistrationBean reg = new ServletRegistrationBean();
		reg.setServlet(new StatViewServlet());
		reg.addUrlMappings("/druid/*");
		reg.addInitParameter("loginUsername", "admin");
		reg.addInitParameter("loginPassword", "admin");
		reg.addInitParameter("logSlowSql", logSlowSql);
		return reg;
	}

	@Bean
	public FilterRegistrationBean filterRegistrationBean() {
		FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean();
		filterRegistrationBean.setFilter(new WebStatFilter());
		filterRegistrationBean.addUrlPatterns("/*");
		filterRegistrationBean.addInitParameter("exclusions", "*.js,*.gif,*.jpg,*.png,*.css,*.ico,/druid/*");
		filterRegistrationBean.addInitParameter("profileEnable", "true");
		return filterRegistrationBean;
	}

	@Bean
	public LocalContainerEntityManagerFactoryBean entityManagerFactory() {
		LocalContainerEntityManagerFactoryBean factory = new LocalContainerEntityManagerFactoryBean();
		factory.setDataSource(dataSource());
		factory.setPersistenceProviderClass(HibernatePersistenceProvider.class);

                /** 按實際項目路徑修改,必須包含Entity和Service*/
		factory.setPackagesToScan("com.cloud");
		Map<String, String> jpaProperties = new HashMap<String, String>();
		jpaProperties.put("hibernate.dialect", dialect);
		jpaProperties.put("hibernate.hbm2ddl.auto", hbm2ddl);
		jpaProperties.put("hibernate.show_sql", show_sql);
		jpaProperties.put("hibernate.format_sql", format_sql);
		
		factory.setJpaPropertyMap(jpaProperties);
		factory.afterPropertiesSet();
		return factory;
	}
        /** 重置JpaTransactionManager EntityManagerFactory，否則數據源切換後事務將不生效*/
	@Bean
	public PlatformTransactionManager transactionManager() {
		JpaTransactionManager transactionManager = new JpaTransactionManager();
		transactionManager.setEntityManagerFactory(entityManagerFactory().getObject());
		return transactionManager;
	}

	@Override
	public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
		app = (ConfigurableApplicationContext) applicationContext;
	}
}

package com.cloud.base.server.config;

import java.util.ArrayList;
import java.util.List;

public class DynamicDataSourceContextHolder {
    
	/** 注意此處有陷阱，因爲我們大多都會用到線程池，而ThreadLocal數據是和線程綁定的。
		所以在每次處理請求完成後必須清空，否則下次線程複用是DataSource就是錯誤的。
		處理方式可以選擇實現ServletRequestListener的requestDestroyed方法。
	*/
	private static final ThreadLocal<String> contextHolder = new ThreadLocal<String>();

	public static List<String> dataSourceIds = new ArrayList<String>();

	public static void setDataSource(String dataSource) {
		contextHolder.set(dataSource);
	}

	public static String getDataSource() {
		return contextHolder.get();
	}

	public static void clearDataSource() {
		contextHolder.remove();
	}

	public static boolean containsDataSource(String dataSourceId) {
		return dataSourceIds.contains(dataSourceId);
	}
}

package com.cloud.base.server.config;

import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;

public class DynamicDataSource extends AbstractRoutingDataSource {

	@Override
	protected Object determineCurrentLookupKey() {
		// TODO Auto-generated method stub
		return DynamicDataSourceContextHolder.getDataSource();
	}
}