jpa与多个数据库

yml 配置

server:
  port: 8081 #设置端口号
spring:
    datasource:  
      primary:  #mysql 数据库
        jdbc-url: jdbc:mysql://localhost:3306/logapi?&characterEncoding=utf-8&serverTimezone=UTC
        username: username
        password: password
        driver-class-name: com.mysql.cj.jdbc.Driver
      secondary:  #oracle 数据库
        jdbc-url: jdbc:oracle:thin:@localhost:test
        username: username
        password: password
        driver-class-name: oracle.jdbc.driver.OracleDriver
    thymeleaf:
      cache: false #关闭缓存，避免修改页面需要重启  
      prefix: classpath:/templates/ #设置路径
      suffix: .html
      mode: HTML
      encoding: UTF-8 #设置字符编码
      servlet:
        content-type: text/html;
    resources:
      static-locations: classpath:/META-INF/resources/,classpath:/resources/,classpath:/static/,classpath:/public/ #配置静态资源路径
    devtools: 
       restart:
        exclude: static/**,public/**
    freemarker:
      check-template-location: false
    jpa:
      database-platform: org.hibernate.dialect.MySQL5Dialect
      show-sql: true #显示sql语句
      hibernate:
        ddl-auto: update  

上面就是配置 yml 文件，连接多个数据库 primary 和 secondary 很重要，等会会用到
DataSourceConfig 配置：

package com.ky.config;

import javax.sql.DataSource;

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;

@Configuration
public class DataSourceConfig {
 	
	@Bean(name = "primaryDataSource")
	@Qualifier("primaryDataSource")
    @ConfigurationProperties(prefix = "spring.datasource.primary") // application.properteis中对应属性的前缀
    public DataSource dataSourcelogapi() {
        return DataSourceBuilder.create().build();
    }
	
	@Bean(name = "secondaryDataSource")
	@Primary
	@Qualifier("secondaryDataSource")
    @ConfigurationProperties(prefix = "spring.datasource.secondary") // application.properteis中对应属性的前缀
    public DataSource primaryDataSource() {
        return DataSourceBuilder.create().build();
    }
}

然后配置 logApi 的连接

package com.ky.config;

import javax.persistence.EntityManager;
import javax.sql.DataSource;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.boot.orm.jpa.EntityManagerFactoryBuilder;
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.transaction.PlatformTransactionManager;
import org.springframework.transaction.annotation.EnableTransactionManagement;

@Configuration
@EnableTransactionManagement
@EnableJpaRepositories(
		entityManagerFactoryRef = "entityManagerFactoryprimary",
		transactionManagerRef = "transactionManagerprimary",
		basePackages = { "com.ky.mapper.logApi" })
public class MybatisDbLogApiConfig {
	
	@Autowired
    @Qualifier("primaryDataSource")
    private DataSource primaryDataSource;

    @Bean(name = "entityManagerprimary")
    @Primary
    public EntityManager entityManager(EntityManagerFactoryBuilder builder) {
    	return entityManagerFactoryprimary(builder).getObject().createEntityManager();
    }
    
    @Primary
    @Bean(name = "entityManagerFactoryprimary")
    public LocalContainerEntityManagerFactoryBean entityManagerFactoryprimary (EntityManagerFactoryBuilder builder) {
        return builder
                .dataSource(primaryDataSource)
                .packages("com.ky.entity.logApi") //设置实体类所在位置
                .persistenceUnit("primaryPersistenceUnit")
                .build();
    }
    
    
    @Primary
    @Bean(name = "transactionManagerprimary")
    public PlatformTransactionManager transactionManagerSecond(EntityManagerFactoryBuilder builder) {
        return new JpaTransactionManager(entityManagerFactoryprimary(builder).getObject());
    }
	
}

然后配置 test 的连接：

package com.ky.config;

import javax.persistence.EntityManager;
import javax.sql.DataSource;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.boot.orm.jpa.EntityManagerFactoryBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
import org.springframework.orm.jpa.JpaTransactionManager;
import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
import org.springframework.transaction.PlatformTransactionManager;
import org.springframework.transaction.annotation.EnableTransactionManagement;

@Configuration
@EnableTransactionManagement
@EnableJpaRepositories(
		entityManagerFactoryRef = "entityManagerFactorysecondary",
		transactionManagerRef = "transactionManagersecondary",
		basePackages = { "com.ky.mapper.crm" })
public class MybatisDbCrmConfig {
	
	@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)
                .packages("com.ky.entity.crm") //设置实体类所在位置
                .persistenceUnit("secondaryPersistenceUnit")
                .build();
    }
    
    
    @Bean(name = "transactionManagersecondary")
    public PlatformTransactionManager transactionManagerSecond(EntityManagerFactoryBuilder builder) {
        return new JpaTransactionManager(entityManagerFactorysecondary(builder).getObject());
    }
	
}

这里只用改一下实体的位置就行了
之后我就写一个实体类的配置，其他都一样
logPool 实体类配置：

package com.ky.entity.logApi;

import java.io.Serializable;
import java.util.Date;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.Table;

import com.fasterxml.jackson.annotation.JsonFormat;

import lombok.Data;

@Data
@Entity
@Table(name = "log_pool")
public class LogPool implements Serializable {
	/**
	 * 
	 */
	private static final long serialVersionUID = 8210837130319782243L;
	@Id
	@GeneratedValue
	private Integer id;
	private String ip;
	@Column(name = "api_name")
	private String apiName;
	@Column(name = "step_state")
	private String stepState;
	private String step1;
	private String step2;
	private String step3;
	private String step4;
	private Date date1;
	private Date date2;
	private Date date3;
	private Date date4;
	private String status;
	private String message;
	private String state;
	private String memo;
	
}

其余的就和 jpa 的操作一样了
这里注意的是：如果不想写 sql 语句，又想使用高级查询，你得这么写

CriteriaBuilder criteriaBuilder = entityManager.getCriteriaBuilder();
CriteriaQuery query = criteriaBuilder.createQuery(LogPool.class);
Root logPoolRoot = query.from(LogPool.class);
List predicatesList = new ArrayList<>();
if(logPool.getIp() != null) {
predicatesList.add(
	criteriaBuilder.and(
			criteriaBuilder.like(
					logPoolRoot.get("ip"),
					"%" + logPool.getIp() + "%")));
}
if(logPool.getApiName() != null) {
predicatesList.add(
	criteriaBuilder.and(
			criteriaBuilder.like(
					logPoolRoot.get("apiName"),
					"%" + logPool.getApiName() + "%")));
}
query.where(predicatesList.toArray(new Predicate[predicatesList.size()]));
TypedQuery typedQuery = entityManager.createQuery(query);
List resultList = typedQuery.getResultList();

这样，就可以写出动态模糊或者如果为空就不查询了