SpringBoot+Druid+Mybatis配置多數據源

時間 2021-01-19

標籤 java mysql web spring sql 數據庫 apache 緩存安全 session 欄目 Spring 简体版

原文原文鏈接

咱們在開發一個項目的時候，可能會遇到須要對多個數據庫進行讀寫的需求，這時候就得在項目中配置多個數據源了。在Java項目的開發中，目前最經常使用的數據操做框架是 Mybatis，開發框架也都基本用上了SpringBoot。而Druid號稱最好的數據庫鏈接池，天然也是被普遍使用。java

因此本文將演示一下，SpringBoot+Druid+Mybatis如何去配置多數據源。首先在IDEA中建立一個SpringBoot工程：

mysql

選擇一些基本的包：
web

完成建立：
spring

pom.xml配置的依賴以下：sql

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
        <groupId>org.mybatis.spring.boot</groupId>
        <artifactId>mybatis-spring-boot-starter</artifactId>
        <version>1.3.2</version>
    </dependency>
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <scope>runtime</scope>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>
    <!-- alibaba的druid數據庫鏈接池 -->
    <dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>druid-spring-boot-starter</artifactId>
        <version>1.1.9</version>
    </dependency>
</dependencies>

接着就是編輯SpringBoot的配置文件，我這裏使用的是yml格式的。須要注意的是，在使用多數據源的狀況下，必須區分出主數據源和從數據源，不然會報錯。application.yml配置文件內容以下：數據庫

spring:
  datasource:
    #使用druid鏈接池
    type: com.alibaba.druid.pool.DruidDataSource

# 自定義的主數據源配置信息
primary:
  datasource:
    #druid相關配置
    druid:
      #監控統計攔截的filters
      filters: stat
      driverClassName: com.mysql.jdbc.Driver
      #配置基本屬性
      url: jdbc:mysql://127.0.0.1:3306/primary_database?useUnicode=true&characterEncoding=UTF-8&allowMultiQueries=true&autoReconnect=true&useSSL=false
      username: root
      password: password
      #配置初始化大小/最小/最大
      initialSize: 1
      minIdle: 1
      maxActive: 20
      #獲取鏈接等待超時時間
      maxWait: 60000
      #間隔多久進行一次檢測，檢測須要關閉的空閒鏈接
      timeBetweenEvictionRunsMillis: 60000
      #一個鏈接在池中最小生存的時間
      minEvictableIdleTimeMillis: 300000
      validationQuery: SELECT 'x'
      testWhileIdle: true
      testOnBorrow: false
      testOnReturn: false
      #打開PSCache，並指定每一個鏈接上PSCache的大小。oracle設爲true，mysql設爲false。分庫分表較多推薦設置爲false
      poolPreparedStatements: false
      maxPoolPreparedStatementPerConnectionSize: 20

# 自定義的從數據源配置信息
back:
  datasource:
    #druid相關配置
    druid:
      #監控統計攔截的filters
      filters: stat
      driverClassName: com.mysql.jdbc.Driver
      #配置基本屬性
      url: jdbc:mysql://127.0.0.1:3306/back_database?useUnicode=true&characterEncoding=UTF-8&allowMultiQueries=true&autoReconnect=true&useSSL=false
      username: root
      password: password
      #配置初始化大小/最小/最大
      initialSize: 1
      minIdle: 1
      maxActive: 20
      #獲取鏈接等待超時時間
      maxWait: 60000
      #間隔多久進行一次檢測，檢測須要關閉的空閒鏈接
      timeBetweenEvictionRunsMillis: 60000
      #一個鏈接在池中最小生存的時間
      minEvictableIdleTimeMillis: 300000
      validationQuery: SELECT 'x'
      testWhileIdle: true
      testOnBorrow: false
      testOnReturn: false
      #打開PSCache，並指定每一個鏈接上PSCache的大小。oracle設爲true，mysql設爲false。分庫分表較多推薦設置爲false
      poolPreparedStatements: false
      maxPoolPreparedStatementPerConnectionSize: 20

而後在項目中新建一個config包，並在該包下建立一個PrimaryDataBaseConfig類，做爲咱們的主數據源配置類，用於加載自定義的主數據源配置信息，以及建立數據源和會話鏈接工廠等實例：apache

package com.dabo.mini.game.zhaxinle.config;

import com.alibaba.druid.pool.DruidDataSource;
import lombok.Data;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.beans.factory.annotation.Qualifier;
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.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;

import javax.sql.DataSource;
import java.sql.SQLException;

/**
 * @ProjectName zhaxinle
 * @Author: zeroJun
 * @Date: 2018/8/16 16:49
 * @Description: 主數據源配置類
 */
@Data
@Configuration
// 前綴爲primary.datasource.druid的配置信息
@ConfigurationProperties(prefix = "primary.datasource.druid")
@MapperScan(basePackages = PrimaryDataBaseConfig.PACKAGE, sqlSessionFactoryRef = "primarySqlSessionFactory")
public class PrimaryDataBaseConfig {

    /**
     * dao層的包路徑
     */
    static final String PACKAGE = "com.dabo.mini.game.zhaxinle.dao.primary";

    /**
     * mapper文件的相對路徑
     */
    private static final String MAPPER_LOCATION = "classpath:mappers/primary/*.xml";

    private String filters;
    private String url;
    private String username;
    private String password;
    private String driverClassName;
    private int initialSize;
    private int minIdle;
    private int maxActive;
    private long maxWait;
    private long timeBetweenEvictionRunsMillis;
    private long minEvictableIdleTimeMillis;
    private String validationQuery;
    private boolean testWhileIdle;
    private boolean testOnBorrow;
    private boolean testOnReturn;
    private boolean poolPreparedStatements;
    private int maxPoolPreparedStatementPerConnectionSize;

    // 主數據源使用@Primary註解進行標識
    @Primary
    @Bean(name = "primaryDataSource")
    public DataSource primaryDataSource() throws SQLException {
        DruidDataSource druid = new DruidDataSource();
        // 監控統計攔截的filters
        druid.setFilters(filters);

        // 配置基本屬性
        druid.setDriverClassName(driverClassName);
        druid.setUsername(username);
        druid.setPassword(password);
        druid.setUrl(url);

        //初始化時創建物理鏈接的個數
        druid.setInitialSize(initialSize);
        //最大鏈接池數量
        druid.setMaxActive(maxActive);
        //最小鏈接池數量
        druid.setMinIdle(minIdle);
        //獲取鏈接時最大等待時間，單位毫秒。
        druid.setMaxWait(maxWait);
        //間隔多久進行一次檢測，檢測須要關閉的空閒鏈接
        druid.setTimeBetweenEvictionRunsMillis(timeBetweenEvictionRunsMillis);
        //一個鏈接在池中最小生存的時間
        druid.setMinEvictableIdleTimeMillis(minEvictableIdleTimeMillis);
        //用來檢測鏈接是否有效的sql
        druid.setValidationQuery(validationQuery);
        //建議配置爲true，不影響性能，而且保證安全性。
        druid.setTestWhileIdle(testWhileIdle);
        //申請鏈接時執行validationQuery檢測鏈接是否有效
        druid.setTestOnBorrow(testOnBorrow);
        druid.setTestOnReturn(testOnReturn);
        //是否緩存preparedStatement，也就是PSCache，oracle設爲true，mysql設爲false。分庫分表較多推薦設置爲false
        druid.setPoolPreparedStatements(poolPreparedStatements);
        // 打開PSCache時，指定每一個鏈接上PSCache的大小
        druid.setMaxPoolPreparedStatementPerConnectionSize(maxPoolPreparedStatementPerConnectionSize);

        return druid;
    }

    // 建立該數據源的事務管理
    @Primary
    @Bean(name = "primaryTransactionManager")
    public DataSourceTransactionManager primaryTransactionManager() throws SQLException {
        return new DataSourceTransactionManager(primaryDataSource());
    }

    // 建立Mybatis的鏈接會話工廠實例
    @Primary
    @Bean(name = "primarySqlSessionFactory")
    public SqlSessionFactory primarySqlSessionFactory(@Qualifier("primaryDataSource") DataSource primaryDataSource) throws Exception {
        final SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
        sessionFactory.setDataSource(primaryDataSource);  // 設置數據源bean
        sessionFactory.setMapperLocations(new PathMatchingResourcePatternResolver()
                .getResources(PrimaryDataBaseConfig.MAPPER_LOCATION));  // 設置mapper文件路徑

        return sessionFactory.getObject();
    }
}

一樣的，還須要建立一個從數據源配置類，與主數據源配置類不一樣的是，從數據源配置類不能使用@Primary註解，即表示它是一個從數據源。代碼以下：緩存

package com.dabo.mini.game.zhaxinle.config;

import com.alibaba.druid.pool.DruidDataSource;
import lombok.Data;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;

import javax.sql.DataSource;
import java.sql.SQLException;

/**
 * @ProjectName zhaxinle
 * @Author: zeroJun
 * @Date: 2018/8/16 16:49
 * @Description: 後臺數據源配置類
 */

@Data
@Configuration
@ConfigurationProperties(prefix = "back.datasource.druid")
@MapperScan(basePackages = BackDataBaseConfig.PACKAGE, sqlSessionFactoryRef = "backSqlSessionFactory")
public class BackDataBaseConfig {

    /**
     * dao層的包路徑
     */
    static final String PACKAGE = "com.dabo.mini.game.zhaxinle.dao.back";

    /**
     * mapper文件的相對路徑
     */
    private static final String MAPPER_LOCATION = "classpath:mappers/back/*.xml";

    private String filters;
    private String url;
    private String username;
    private String password;
    private String driverClassName;
    private int initialSize;
    private int minIdle;
    private int maxActive;
    private long maxWait;
    private long timeBetweenEvictionRunsMillis;
    private long minEvictableIdleTimeMillis;
    private String validationQuery;
    private boolean testWhileIdle;
    private boolean testOnBorrow;
    private boolean testOnReturn;
    private boolean poolPreparedStatements;
    private int maxPoolPreparedStatementPerConnectionSize;

    @Bean(name = "backDataSource")
    public DataSource backDataSource() throws SQLException {
        DruidDataSource druid = new DruidDataSource();
        // 監控統計攔截的filters
        druid.setFilters(filters);

        // 配置基本屬性
        druid.setDriverClassName(driverClassName);
        druid.setUsername(username);
        druid.setPassword(password);
        druid.setUrl(url);

        //初始化時創建物理鏈接的個數
        druid.setInitialSize(initialSize);
        //最大鏈接池數量
        druid.setMaxActive(maxActive);
        //最小鏈接池數量
        druid.setMinIdle(minIdle);
        //獲取鏈接時最大等待時間，單位毫秒。
        druid.setMaxWait(maxWait);
        //間隔多久進行一次檢測，檢測須要關閉的空閒鏈接
        druid.setTimeBetweenEvictionRunsMillis(timeBetweenEvictionRunsMillis);
        //一個鏈接在池中最小生存的時間
        druid.setMinEvictableIdleTimeMillis(minEvictableIdleTimeMillis);
        //用來檢測鏈接是否有效的sql
        druid.setValidationQuery(validationQuery);
        //建議配置爲true，不影響性能，而且保證安全性。
        druid.setTestWhileIdle(testWhileIdle);
        //申請鏈接時執行validationQuery檢測鏈接是否有效
        druid.setTestOnBorrow(testOnBorrow);
        druid.setTestOnReturn(testOnReturn);
        //是否緩存preparedStatement，也就是PSCache，oracle設爲true，mysql設爲false。分庫分表較多推薦設置爲false
        druid.setPoolPreparedStatements(poolPreparedStatements);
        // 打開PSCache時，指定每一個鏈接上PSCache的大小
        druid.setMaxPoolPreparedStatementPerConnectionSize(maxPoolPreparedStatementPerConnectionSize);

        return druid;
    }

    @Bean(name = "backTransactionManager")
    public DataSourceTransactionManager backTransactionManager() throws SQLException {
        return new DataSourceTransactionManager(backDataSource());
    }

    @Bean(name = "backSqlSessionFactory")
    public SqlSessionFactory backSqlSessionFactory(@Qualifier("backDataSource") DataSource backDataSource) throws Exception {
        final SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
        sessionFactory.setDataSource(backDataSource);
        sessionFactory.setMapperLocations(new PathMatchingResourcePatternResolver()
                .getResources(BackDataBaseConfig.MAPPER_LOCATION));

        return sessionFactory.getObject();
    }
}

完成以上配置後，該工程就具備鏈接兩個數據庫的能力了，若是要配置兩個以上的數據庫也是同樣的，配置多個從數據源便可。業務代碼層面除了須要將不一樣的數據源相關的mapper、dao、pojo分包存放方便掃描以外，代碼上的編寫仍是和以前單數據源的時候同樣，因此這裏就不貼出業務代碼了。安全