springboot+hibernate如何简单配置多个数据源

刺骨的言语ヽ痛彻心扉 2022-09-08 15:57 318阅读 0赞

前言：

1，业务需求：使用原生的hibernate连接数据库，数据来源是两个数据库，并且为了后期维护，需要将数据库账号密码重hibernate.cfg.xml中抽离出来，放到properties文件中读取

2，网上有很多教程，说是hibernate进行配置，实质上是jpa

3，本文章适合对hibernate基本使用有了解的人

4，由于笔记本上只有一个数据库，所以模拟过程中有些不严谨，两个数据库连接，连的是同一个数据库，但过程是这么个过程

5，这里没有将与数据库相关的对象注入到spring容器中。

1，引入hibernate的pom.xml文件

2，编写hibernate.cfg.xml文件

3，编写hibernate.properties文件

4，编写实体类

5，编写测试案例

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pom.xml   ：这里有其它与本文无关的内容，根据需求进行删除

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
        <modelVersion>4.0.0</modelVersion>
        <groupId>com.example</groupId>
        <artifactId>demo2</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <name>demo2</name>
        <description>Demo project for Spring Boot</description>
    
        <properties>
            <java.version>1.8</java.version>
            <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
            <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
            <spring-boot.version>2.3.7.RELEASE</spring-boot.version>
        </properties>
        <dependencies>
            
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
            </dependency>
            
            <dependency>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
                <optional>true</optional>
            </dependency>
            
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-test</artifactId>
                <scope>test</scope>
                <exclusions>
                    <exclusion>
                        <groupId>org.junit.vintage</groupId>
                        <artifactId>junit-vintage-engine</artifactId>
                    </exclusion>
                </exclusions>
            </dependency>
            
            <dependency>
                <groupId>org.thymeleaf</groupId>
                <artifactId>thymeleaf</artifactId>
                <version>3.0.12.RELEASE</version>
            </dependency>
            
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-thymeleaf</artifactId>
            </dependency>
            
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-jdbc</artifactId>
            </dependency>
            
            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <version>5.1.37</version>
                <scope>runtime</scope>
            </dependency>
            
            <dependency>
                <groupId>org.mybatis.spring.boot</groupId>
                <artifactId>mybatis-spring-boot-starter</artifactId>
                <version>2.1.1</version>
            </dependency>
            
            <dependency>
                <groupId>net.sourceforge.jexcelapi</groupId>
                <artifactId>jxl</artifactId>
                <version>2.6</version>
            </dependency>
            
            <dependency>
                <groupId>org.hibernate</groupId>
                <artifactId>hibernate-core</artifactId>
            </dependency>
        </dependencies>
    
        <dependencyManagement>
            <dependencies>
                <dependency>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-dependencies</artifactId>
                    <version>${spring-boot.version}</version>
                    <type>pom</type>
                    <scope>import</scope>
                </dependency>
            </dependencies>
        </dependencyManagement>
    
        <build>
            <plugins>
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-compiler-plugin</artifactId>
                    <version>3.8.1</version>
                    <configuration>
                        <source>1.8</source>
                        <target>1.8</target>
                        <encoding>UTF-8</encoding>
                    </configuration>
                </plugin>
                <plugin>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-maven-plugin</artifactId>
                    <version>2.3.7.RELEASE</version>
                    <configuration>
                        <mainClass>com.example.demo2.Demo2Application</mainClass>
                    </configuration>
                    <executions>
                        <execution>
                            <id>repackage</id>
                            <goals>
                                <goal>repackage</goal>
                            </goals>
                        </execution>
                    </executions>
                </plugin>
            </plugins>
        </build>
    
    </project>

hibernate1.cfg.xml

<?xml version="1.0" encoding="UTF-8"?>
    <!DOCTYPE hibernate-configuration PUBLIC
            "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
            "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
    <hibernate-configuration>
        
        <session-factory>
            
            <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
            
            <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
            <mapping class="com.example.demo2.pojo.Student" />
        </session-factory>
    </hibernate-configuration>

hibernate2.cfg.xml  内容与上面的一样，我电脑上只有一个数据库只有这样模拟了，没办法

hibernate1.properties

hibernate.connection.url=jdbc:mysql://localhost:3306/test?severTimezone=UTC&useUnicode=true&characterEncoding=utf-8
    hibernate.connection.password=123
    hibernate.connection.username=root

hibernate2.properties  内容与上面的一样，我电脑上只有一个数据库只有这样模拟了，没办法

hibernate.connection.url=jdbc:mysql://localhost:3306/test?severTimezone=UTC&useUnicode=true&characterEncoding=utf-8
    hibernate.connection.password=123
    hibernate.connection.username=root

实体类 student.class

package com.example.demo2.pojo;
    
    import lombok.AllArgsConstructor;
    import lombok.Data;
    import lombok.NoArgsConstructor;
    
    import javax.persistence.*;
    
    @AllArgsConstructor
    @NoArgsConstructor
    @Data
    
    @Entity
    @Table()
    public class Student {
        @Id
        @GeneratedValue(strategy = GenerationType.IDENTITY)
        private Integer id;
        private String name;
        private String password;
    }

测试代码 test1.class

package com.example.demo2;
    
    import com.example.demo2.pojo.Student;
    import org.hibernate.Session;
    import org.hibernate.SessionFactory;
    import org.hibernate.boot.MetadataSources;
    import org.hibernate.boot.registry.StandardServiceRegistry;
    import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
    import org.hibernate.query.NativeQuery;
    import org.junit.jupiter.api.Test;
    import java.util.List;
    
    public class Test1 {
        public static StandardServiceRegistry registry1;
        public static Session session1;
        public static SessionFactory factory1;
    
        public static StandardServiceRegistry registry2;
        public static Session session2;
        public static SessionFactory factory2;
    
        static {
            registry1=new StandardServiceRegistryBuilder().configure("hibernate1.cfg.xml")
                    .loadProperties("hibernate1.properties").build();
            factory1=new MetadataSources(registry1).buildMetadata().buildSessionFactory();
            session1=factory1.openSession();
    
            registry2=new StandardServiceRegistryBuilder().configure("hibernate2.cfg.xml")
                    .loadProperties("hibernate2.properties").build();
            factory2=new MetadataSources(registry2).buildMetadata().buildSessionFactory();
            session2=factory1.openSession();
        }
    
        @Test
        public void getStudent1()
        {
            //两个session是不同的，他们是有不同的工厂创建出来的
            System.out.println(session1==session2);
            NativeQuery nativeQuery1 = session1.createSQLQuery("select * from student").addEntity(Student.class);
            List<Student> list1 = nativeQuery1.list();
            if (!list1.isEmpty())
                for (Student student:list1)
                    System.out.println(student);
            session1.close();
        }
    
        @Test
        public void getStudent2()
        {
            NativeQuery nativeQuery2 = session2.createSQLQuery("select * from student").addEntity(Student.class);
            List<Student> list2 = nativeQuery2.list();
            if (!list2.isEmpty())
                for (Student student:list2)
                    System.out.println(student);
            session2.close();
        }
    
    
    
    
    }

测试结果：

![watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBA6ZmI5bu65rGf77yB_size_20_color_FFFFFF_t_70_g_se_x_16][]

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