关于
有时候，随着业务的发展，项目关联的数据来源会变得越来越复杂，使用的数据库会比较分散，这个时候就会采用多数据源的方式来获取数据。另外，多数据源也有其他好处，例如分布式数据库的读写分离，集成多种数据库等等。
下面分享我在实际项目中配置多数据源的案例。话不多说了，来一起看看详细的介绍吧
步骤
1.application.yml文件中，配置数据库源。这里primary是主库，secondary是从库。
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server: port: 8089# 多数据源配置#primaryspring: primary: datasource: url: jdbc:mysql://127.0.0.1:3306/database1?autoreconnect=true&useunicode=true&characterencoding=utf-8&usessl=false&uselegacydatetimecode=false&servertimezone=asia/shanghai username: root password: ****** driver-class-name: com.mysql.jdbc.driver #secondary secondary: datasource: url: jdbc:mysql://127.0.0.1:3306/database1?autoreconnect=true&useunicode=true&characterencoding=utf-8&usessl=false&uselegacydatetimecode=false&servertimezone=asia/shanghai username: root password: ****** driver-class-name: com.mysql.jdbc.driver jpa: hibernate: primary-dialect: org.hibernate.dialect.mysql5dialect secondary-dialect: org.hibernate.dialect.mysql5dialect open-in-view: true show-sql: true |
2.创建一个spring配置类，其中spring.primary.datasource的路径参考yml文件的配置。
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@configurationpublic class datasourceconfig { @bean(name = "primarydatasource") @qualifier("primarydatasource") @configurationproperties(prefix="spring.primary.datasource") public datasource primarydatasource() { return datasourcebuilder.create().build(); } @bean(name = "secondarydatasource") @qualifier("secondarydatasource") @primary @configurationproperties(prefix="spring.secondary.datasource") public datasource secondarydatasource() { return datasourcebuilder.create().build(); }} |
3.分别创建主库、从库的配置类。
注意：entity包和dao包的配置，以及@primary注解指定主库。
主库配置类：
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@configuration@enabletransactionmanagement@enablejparepositories( entitymanagerfactoryref = "entitymanagerfactoryprimary", transactionmanagerref = "transactionmanagerprimary", basepackages = {"com.infinitus.yunxiao_data.dao.primary"}) //设置repository所在位置public class primaryconfig { @autowired private jpaproperties jpaproperties; @autowired @qualifier("primarydatasource") private datasource primarydatasource; @primary @bean(name = "entitymanagerprimary") public entitymanager entitymanager(entitymanagerfactorybuilder builder) { return entitymanagerfactoryprimary(builder).getobject().createentitymanager(); } @primary @bean(name = "entitymanagerfactoryprimary") public localcontainerentitymanagerfactorybean entitymanagerfactoryprimary(entitymanagerfactorybuilder builder) { return builder .datasource(primarydatasource) .properties(getvendorproperties(primarydatasource)) .packages("com.infinitus.yunxiao_data.entity.primary") //设置实体类所在位置 .persistenceunit("primarypersistenceunit") .build(); } private map getvendorproperties(datasource datasource) { return jpaproperties.gethibernateproperties(datasource); } @primary @bean(name = "transactionmanagerprimary") public platformtransactionmanager transactionmanagerprimary(entitymanagerfactorybuilder builder) { return new jpatransactionmanager(entitymanagerfactoryprimary(builder).getobject()); }} |
从库的配置类：
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@configuration@enabletransactionmanagement@enablejparepositories( entitymanagerfactoryref = "entitymanagerfactorysecondary", transactionmanagerref = "transactionmanagersecondary", basepackages = {"com.infinitus.yunxiao_data.dao.secondary"}) //设置repository所在位置public class secondaryconfig { @autowired private jpaproperties jpaproperties; @autowired @qualifier("secondarydatasource") private datasource secondarydatasource; @bean(name = "entitymanagersecondary") public entitymanager entitymanager(entitymanagerfactorybuilder builder) { return entitymanagerfactorysecondary(builder).getobject().createentitymanager(); } @bean(name = "entitymanagerfactorysecondary") public localcontainerentitymanagerfactorybean entitymanagerfactorysecondary(entitymanagerfactorybuilder builder) { return builder .datasource(secondarydatasource) .properties(getvendorproperties(secondarydatasource)) .packages("com.infinitus.yunxiao_data.entity.secondary") //设置实体类所在位置 .persistenceunit("primarypersistenceunit") .build(); } private map getvendorproperties(datasource datasource) { return jpaproperties.gethibernateproperties(datasource); } @bean(name = "transactionmanagersecondary") platformtransactionmanager transactionmanagersecondary(entitymanagerfactorybuilder builder) { return new jpatransactionmanager(entitymanagerfactorysecondary(builder).getobject()); }} |
4.分别创建主、从库dao类。
主dao：
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@repositorypublic interface primaryrepository extends jparepository<primaryentity, long> { @query(value = "select p from primaryentity p") list<primaryentity> querylist();} |
从dao：
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@repositorypublic interface secondaryrepository extends jparepository<secondaryentity, long> { @query(value = "select p from secondaryentity p") list<secondaryentity> querylist();} |
5.分别创建主、从库entity类。
主entity：
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@entity@table(name = "holiday_scheme")@entitylisteners(auditingentitylistener.class)public class primaryentity extends abstractpersistable<long> { @column(name = "date") public string date; @column(name = "hour") public string hour; @column(name = "holiday") public string holiday; @column(name = "holiday_explain") public string holiday_explain; public string getdate() { return date; } public void setdate(string date) { this.date = date; } public string gethour() { return hour; } public void sethour(string hour) { this.hour = hour; } public string getholiday() { return holiday; } public void setholiday(string holiday) { this.holiday = holiday; } public string getholiday_explain() { return holiday_explain; } public void setholiday_explain(string holiday_explain) { this.holiday_explain = holiday_explain; } @override public string tostring() { return "primaryentity{" + "date='" + date + '\'' + ", hour='" + hour + '\'' + ", holiday='" + holiday + '\'' + ", holiday_explain='" + holiday_explain + '\'' + '}'; }} |
从entity：
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@entity@table(name = "active_dashboards")@entitylisteners(auditingentitylistener.class)public class secondaryentity extends abstractpersistable<long> { @column(name = "dashboard_id") public string dashboard_id; @column(name = "user_id") public string user_id; @column(name = "order_index") public string order_index; public string getdashboard_id() { return dashboard_id; } public void setdashboard_id(string dashboard_id) { this.dashboard_id = dashboard_id; } public string getuser_id() { return user_id; } public void setuser_id(string user_id) { this.user_id = user_id; } public string getorder_index() { return order_index; } public void setorder_index(string order_index) { this.order_index = order_index; } @override public string tostring() { return "secondaryentity{" + "dashboard_id='" + dashboard_id + '\'' + ", user_id='" + user_id + '\'' + ", order_index='" + order_index + '\'' + '}'; }} |
6.controller请求获取不同数据库的数据。
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@restcontroller@requestmapping("/database")public class mailcontroller { private final logger logger = loggerfactory.getlogger(this.getclass()); @autowired primaryrepository primaryrepository; @autowired secondaryrepository secondaryrepository; @requestmapping("/primary") @responsebody public string primary() { return primaryrepository.querylist().tostring(); } @requestmapping("/secondary") @responsebody public string secondary() { return secondaryrepository.querylist().tostring(); }} |
注意
下面提两个在配置多数据源时遇到的坑点，一不注意就掉坑了。
1.application类不需要配置@enablejparepositories注解，会报如下错误。
a component required a bean named 'entitymanagerfactory' that could not be f
2.注意检查dao类，获取数据的方法上格式是否正确，有没有某个字段是表中不存在的，避免启动异常。如下，secondaryentity表中是不存在job_name字段的，所以注释掉才能启动成功等。
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//@query(value = "select p from secondaryentity p where p.job_name = ?1")//list<secondaryentity> queryodcrecord(string job_name); |
总结
以上就是这篇文章的全部内容了，希望本文的内容对大家的学习或者工作具有一定的参考学习价值，如果有疑问大家可以留言交流，谢谢大家对服务器之家的支持。
原文链接：https://huangweicai.github.io/2019/01/08/SpringBoot+Jpa多数据源配置/
