我尝试创建一个Spring Boot应用程序，它连接两个数据源。 我可以通过遵循Spring Documentation实现这一目标，但我面临的挑战是实现以下目标
我的application.yml看起来像
server:
port: 9001
contextPath: /ready
spring:
datasource:
one:
url: jdbc:mysql://localhost:3307/dummy
driver-class-name: com.mysql.jdbc.Driver
username: root
password: root
two:
url: jdbc:mysql://localhost:3307/dummy_two
driver-class-name: com.mysql.jdbc.Driver
username: root
password: root
---
spring:
profiles: DEV
spring.datasource:
one:
jndi-name: jdbc/myDBOne
two:
jndi-name: jdbc/myDBTwo
两个数据源的JpaConfig类如下：
package com.springboot.web.config;
import javax.persistence.EntityManagerFactory;
import javax.sql.DataSource;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.boot.autoconfigure.jdbc.DataSourceBuilder;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
import org.springframework.orm.jpa.JpaTransactionManager;
import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
import org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter;
import org.springframework.transaction.PlatformTransactionManager;
import org.springframework.transaction.annotation.EnableTransactionManagement;
/**
*
* @author amardeep2551
*/
@Configuration
@EnableTransactionManagement
@EnableJpaRepositories(
entityManagerFactoryRef = "entityManagerFactoryOne",
basePackages = { "com.springboot.web.repo.one" })
public class JpaConfigOne {
@Primary
@Bean(name = "entityManagerFactoryOne")
@ConfigurationProperties(prefix = "spring.datasource.one")
public LocalContainerEntityManagerFactoryBean entityManagerFactoryOne(
DataSource dataSource
) {
LocalContainerEntityManagerFactoryBean lef = new LocalContainerEntityManagerFactoryBean();
lef.setPackagesToScan("com.springboot.web.domain.one");
lef.setDataSource(dataSource);
lef.setJpaVendorAdapter(new HibernateJpaVendorAdapter());
return lef;
}
@Primary
@Bean(name = "transactionManager")
public PlatformTransactionManager transactionManager(
@Qualifier("entityManagerFactoryOne") EntityManagerFactory entityManagerFactoryOne) {
return new JpaTransactionManager(entityManagerFactoryOne);
}
}
/*
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package com.springboot.web.config;
import javax.persistence.EntityManagerFactory;
import javax.sql.DataSource;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.boot.autoconfigure.jdbc.DataSourceBuilder;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
import org.springframework.orm.jpa.JpaTransactionManager;
import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
import org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter;
import org.springframework.transaction.PlatformTransactionManager;
import org.springframework.transaction.annotation.EnableTransactionManagement;
/**
*
* @author amardeep2551
*/
@Configuration
@EnableTransactionManagement
@EnableJpaRepositories(
entityManagerFactoryRef = "entityManagerFactoryTwo",
basePackages = { "com.springboot.web.repo.two" })
public class JpaConfigTwo {
@Bean(name = "entityManagerFactoryTwo")
@ConfigurationProperties(prefix = "spring.datasource.two")
public LocalContainerEntityManagerFactoryBean entityManagerFactory(
DataSource dataSource
) {
LocalContainerEntityManagerFactoryBean lef = new LocalContainerEntityManagerFactoryBean();
lef.setPackagesToScan("com.springboot.web.domain.two");
lef.setDataSource(dataSource);
lef.setJpaVendorAdapter(new HibernateJpaVendorAdapter());
return lef;
}
@Primary
@Bean(name = "transactionManager")
public PlatformTransactionManager transactionManager(
@Qualifier("entityManagerFactoryTwo") EntityManagerFactory entityManagerFactory) {
return new JpaTransactionManager(entityManagerFactory);
}
}
My Spring Boot Launch Class如下：
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*/
package com.springboot.web;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;
import org.springframework.boot.autoconfigure.jdbc.JndiDataSourceAutoConfiguration;
import org.springframework.boot.autoconfigure.jmx.JmxAutoConfiguration;
import org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration;
import org.springframework.boot.context.web.SpringBootServletInitializer;
/**
*
* @author amardeep2551
*/
@EnableAutoConfiguration
@SpringBootApplication()
public class Application extends SpringBootServletInitializer{
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
}
最后我的pom.xml看起来像
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.3.1.RELEASE</version>
<relativePath /> <!-- lookup parent from repository -->
</parent>
<groupId>com.springboot.web</groupId>
<artifactId>SpringBootWeb</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>war</packaging>
<name>SpringBootWeb</name>
<properties>
<java.version>1.8</java.version>
<endorsed.dir>${project.build.directory}/endorsed</endorsed.dir>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.14.4</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
</dependency>
<dependency>
<groupId>javax</groupId>
<artifactId>javaee-web-api</artifactId>
<version>6.0</version>
<scope>provided</scope>
</dependency>
</dependencies>
<build>
<resources>
<resource>
<directory>src/main/resources</directory>
</resource>
</resources>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>2.3.2</version>
<configuration>
<source>1.6</source>
<target>1.6</target>
<compilerArguments>
<endorseddirs>${endorsed.dir}</endorseddirs>
</compilerArguments>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-war-plugin</artifactId>
<version>2.1.1</version>
<configuration>
<failOnMissingWebXml>false</failOnMissingWebXml>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-dependency-plugin</artifactId>
<version>2.1</version>
<executions>
<execution>
<phase>validate</phase>
<goals>
<goal>copy</goal>
</goals>
<configuration>
<outputDirectory>${endorsed.dir}</outputDirectory>
<silent>true</silent>
<artifactItems>
<artifactItem>
<groupId>javax</groupId>
<artifactId>javaee-endorsed-api</artifactId>
<version>6.0</version>
<type>jar</type>
</artifactItem>
</artifactItems>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>
<repositories>
<repository>
<id>projectlombok.org</id>
<name>Lombok Repository</name>
<url>http://projectlombok.org/mavenrepo</url>
</repository>
</repositories>
</project>
现在，当我在Application.java中运行main方法时，我得到以下错误
org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'entityManagerFactoryOne' defined in class path resource [com/springboot/web/config/JpaConfigOne.class]: Unsatisfied dependency expressed through constructor argument with index 0 of type [javax.sql.DataSource]: : Error creating bean with name 'dataSource' defined in class path resource [org/springframework/boot/autoconfigure/jdbc/DataSourceAutoConfiguration$NonEmbeddedConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [javax.sql.DataSource]: Factory method 'dataSource' threw exception; nested exception is org.springframework.boot.autoconfigure.jdbc.DataSourceProperties$DataSourceBeanCreationException: Cannot determine embedded database driver class for database type NONE. If you want an embedded database please put a supported one on the classpath. If you have database settings to be loaded from a particular profile you may need to active it (no profiles are currently active).; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dataSource' defined in class path resource [org/springframework/boot/autoconfigure/jdbc/DataSourceAutoConfiguration$NonEmbeddedConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [javax.sql.DataSource]: Factory method 'dataSource' threw exception; nested exception is org.springframework.boot.autoconfigure.jdbc.DataSourceProperties$DataSourceBeanCreationException: Cannot determine embedded database driver class for database type NONE. If you want an embedded database please put a supported one on the classpath. If you have database settings to be loaded from a particular profile you may need to active it (no profiles are currently active).
at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:749) ~[spring-beans-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:464) ~[spring-beans-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1123) ~[spring-beans-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1018) ~[spring-beans-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:510) ~[spring-beans-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482) ~[spring-beans-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) ~[spring-beans-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) ~[spring-beans-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) ~[spring-beans-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) ~[spring-beans-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1054) ~[spring-context-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:829) ~[spring-context-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:538) ~[spring-context-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:118) ~[spring-boot-1.3.1.RELEASE.jar:1.3.1.RELEASE]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:764) [spring-boot-1.3.1.RELEASE.jar:1.3.1.RELEASE]
at org.springframework.boot.SpringApplication.doRun(SpringApplication.java:357) [spring-boot-1.3.1.RELEASE.jar:1.3.1.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:305) [spring-boot-1.3.1.RELEASE.jar:1.3.1.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1124) [spring-boot-1.3.1.RELEASE.jar:1.3.1.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1113) [spring-boot-1.3.1.RELEASE.jar:1.3.1.RELEASE]
at com.springboot.web.Application.main(Application.java:26) [classes/:na]
我理解错误的原因，即在下面的方法中注入DataSource时Spring无法将属性与spring.datasource.one前缀相关联，因此无法确定数据库类型。
@Primary
@Bean(name = "entityManagerFactoryOne")
@ConfigurationProperties(prefix = "spring.datasource.one")
public LocalContainerEntityManagerFactoryBean entityManagerFactoryOne(
DataSource dataSource
) {
有没有办法使用Spring Boot配置的Spring Boot实现这一点，或者我必须根据配置文件创建不同的DataSource bean。
答案 0 :(得分：0)
在我的例子中，使用application.properties文件进行配置。
datasource.one.url=jdbc:mysql://localhost:3306/demo_one
datasource.one.username=root
datasource.one.password=root
datasource.one.driver-class-name=com.mysql.jdbc.Driver
datasource.two.url=jdbc:mysql://localhost:3306/demo_two
datasource.two.username=root
datasource.two.password=root
datasource.two.driver-class-name=com.mysql.jdbc.Driver
然后相应地为JPA Configuration类中的每个datasource使用前缀。不确定基于yml文件的配置。
答案 1 :(得分：0)
您可以编辑文件JpaConfigOne.java，内容如下：
@Bean(name = "oneDataSource")
@ConfigurationProperties(prefix = "spring.datasource.one")
public DataSource dataSource() {
return DataSourceBuilder.create().build();
}
@Primary
@Bean(name = "entityManagerFactoryOne")
public LocalContainerEntityManagerFactoryBean entityManagerFactoryOne(@Qualifier("oneDataSource") DataSource dataSource) {
LocalContainerEntityManagerFactoryBean lef = new LocalContainerEntityManagerFactoryBean();
lef.setPackagesToScan("com.springboot.web.domain.one");
lef.setDataSource(dataSource);
lef.setJpaVendorAdapter(new HibernateJpaVendorAdapter());
return lef;
}
并编辑JpaConfigTwo.java文件：
@Bean(name = "twoDataSource")
@ConfigurationProperties(prefix = "spring.datasource.two")
public DataSource dataSource() {
return DataSourceBuilder.create().build();
}
@Primary
@Bean(name = "entityManagerFactoryTwo")
public LocalContainerEntityManagerFactoryBean entityManagerFactory(@Qualifier("twoDataSource") DataSource dataSource) {
LocalContainerEntityManagerFactoryBean lef = new LocalContainerEntityManagerFactoryBean();
lef.setPackagesToScan("com.springboot.web.domain.two");
lef.setDataSource(dataSource);
lef.setJpaVendorAdapter(new HibernateJpaVendorAdapter());
return lef;
}
并且您的代码具有两个相同名称的@Bean（name =“ transactionManager”）。您必须更改bean名称。确保bean名称唯一