spring多数据源配置

项目中我们经常会遇到多数据源的问题，尤其是数据同步或定时任务等项目更是如此。多数据源让人最头痛的，不是配置多个数据源，而是如何能灵活动态的切换数据源。绑定给sessionFactory，在dao层代码中再指定sessionFactory来进行数据库操作。

正如上图所示，每一块都是指定绑死的，如果是多个数据源，也只能是下图中那种方式。

可看出在Dao层代码中写死了两个SessionFactory，这样日后如果再多一个数据源，还要改代码添加一个SessionFactory，显然这并不符合开闭原则。

那么正确的做法应该是下载

代码：下载

1. applicationContext.xml

[html] view plain copy

1. xml version="1.0" encoding="UTF-8"?>
2. << span="">beans xmlns="http://www.springframework.org/schema/beans"
3. xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:aop="http://www.springframework.org/schema/aop"
4. xmlns:cache="http://www.springframework.org/schema/cache"
5. xmlns:context="http://www.springframework.org/schema/context"
6. xmlns:jdbc="http://www.springframework.org/schema/jdbc" xmlns:jee="http://www.springframework.org/schema/jee"
7. xmlns:jms="http://www.springframework.org/schema/jms" xmlns:lang="http://www.springframework.org/schema/lang"
8. xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:oxm="http://www.springframework.org/schema/oxm"
9. xmlns:p="http://www.springframework.org/schema/p" xmlns:task="http://www.springframework.org/schema/task"
10. xmlns:tx="http://www.springframework.org/schema/tx" xmlns:util="http://www.springframework.org/schema/util"
11. xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
12. http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.1.xsd
13. http://www.springframework.org/schema/cache http://www.springframework.org/schema/cache/spring-cache-3.1.xsd
14. http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.1.xsd
15. http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-3.1.xsd
16. http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-3.1.xsd
17. http://www.springframework.org/schema/jms http://www.springframework.org/schema/jms/spring-jms-3.1.xsd
18. http://www.springframework.org/schema/lang http://www.springframework.org/schema/lang/spring-lang-3.1.xsd
19. http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.1.xsd
20. http://www.springframework.org/schema/oxm http://www.springframework.org/schema/oxm/spring-oxm-3.1.xsd
21. http://www.springframework.org/schema/task http://www.springframework.org/schema/task/spring-task-3.1.xsd
22. http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.1.xsd
23. http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.1.xsd">
24. << span="">context:annotation-config />
25. << span="">context:component-scan base-package="com">context:component-scan>
26. << span="">bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
27. << span="">property name="locations">
28. << span="">list>
29. << span="">value>classpath:com/resource/config.propertiesvalue>
30. list>
31. property>
32. bean>
33. << span="">bean id="dataSourceOne" class="com.mchange.v2.c3p0.ComboPooledDataSource"
34. destroy-method="close">
35. << span="">property name="driverClass" value="${dbOne.jdbc.driverClass}" />
36. << span="">property name="jdbcUrl" value="${dbOne.jdbc.url}" />

2. DynamicDataSource.class下载

[java] view plain copy

1. package com.core;
2. import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;
3. public class DynamicDataSource extends AbstractRoutingDataSource{
4. @Override
5. protected Object determineCurrentLookupKey() {
6. return DatabaseContextHolder.getCustomerType();
7. }
8. }

3. DatabaseContextHolder.class下载

[java] view plain copy

1. package com.core;
2. public class DatabaseContextHolder {
3. private static final ThreadLocal contextHolder = new ThreadLocal();
4. public static void setCustomerType(String customerType) {
5. contextHolder.set(customerType);
6. }
7. public static String getCustomerType() {
8. return contextHolder.get();
9. }
10. public static void clearCustomerType() {
11. contextHolder.remove();
12. }
13. }

4. DataSourceInterceptor.class

[java] view plain copy

1. package com.core;
2. import org.aspectj.lang.JoinPoint;
3. import org.springframework.stereotype.Component;
4. @Component
5. public class DataSourceInterceptor {
6. public void setdataSourceOne(JoinPoint jp) {
7. DatabaseContextHolder.setCustomerType("dataSourceOne");
8. }
9. public void setdataSourceTwo(JoinPoint jp) {
10. DatabaseContextHolder.setCustomerType("dataSourceTwo");
11. }
12. }

5. po实体类下载

[java] view plain copy

1. package com.po;
2. import javax.persistence.Column;
3. import javax.persistence.Entity;
4. import javax.persistence.Id;
5. import javax.persistence.Table;
6. @Entity
7. @Table(name = "BTSF_BRAND", schema = "hotel")
8. public class Brand {
9. private String id;
10. private String names;
11. private String url;
12. @Id
13. @Column(name = "ID", unique = true, nullable = false, length = 10)
14. public String getId() {
15. return this.id;
16. }
17. public void setId(String id) {
18. this.id = id;
19. }
20. @Column(name = "NAMES", nullable = false, length = 50)
21. public String getNames() {
22. return this.names;
23. }
24. public void setNames(String names) {
25. this.names = names;
26. }
27. @Column(name = "URL", length = 200)
28. public String getUrl() {
29. return this.url;
30. }
31. public void setUrl(String url) {
32. this.url = url;
33. }
34. }

[java] view plain copy

1. package com.po;
2. import javax.persistence.Column;
3. import javax.persistence.Entity;
4. import javax.persistence.Id;
5. import javax.persistence.Table;
6. @Entity
7. @Table(name = "CITY", schema = "car")
8. public class City {
9. private Integer id;
10. private String name;
11. @Id
12. @Column(name = "ID", unique = true, nullable = false)
13. public Integer getId() {
14. return id;
15. }
16. public void setId(Integer id) {
17. this.id = id;
18. }
19. @Column(name = "NAMES", nullable = false, length = 50)
20. public String getName() {
21. return name;
22. }
23. public void setName(String name) {
24. this.name = name;
25. }
26. }

6. BrandDaoImpl.class下载