SpringBoot 自定義+動態切換數據源教程

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1、添加maven依賴

<dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.1.3</version>
        </dependency>
        <!--properties動態註入-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-configuration-processor</artifactId>
            <optional>true</optional>
        </dependency>
        <!--springBoot的aop-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-aop</artifactId>
        </dependency>

2、配置application.yml

# 數據庫訪問配置
# 主數據源，默認的
druid:
  datasource:
    type: com.alibaba.druid.pool.DruidDataSource
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql://192.168.1.113:3306/test?useUnicode=true&characterEncoding=utf-8
    username: root
    password: root
    # 下面為連接池的補充設置，應用到上面所有數據源中
    # 初始化大小，最小，最大
    initialSize: 5
    minIdle: 5
    maxActive: 20
    # 配置獲取連接等待超時的時間
    maxWait: 60000
    # 配置間隔多久才進行一次檢測，檢測需要關閉的空閑連接，單位是毫秒
    timeBetweenEvictionRunsMillis: 60000
    # 配置一個連接在池中最小生存的時間，單位是毫秒
    minEvictableIdleTimeMillis: 300000
    validationQuery: SELECT 1 FROM DUAL
    testWhileIdle: true
    testOnBorrow: false
    testOnReturn: false
    # 打開PSCache，並且指定每個連接上PSCache的大小
    poolPreparedStatements: true
    maxPoolPreparedStatementPerConnectionSize: 20
    # 配置監控統計攔截的filters，去掉後監控界面sql無法統計，'wall'用於防火墻
    filters: stat,wall,log4j
    # 通過connectProperties屬性來打開mergeSql功能；慢SQL記錄
    connectionProperties:
      druid:
        stat:
          mergeSql: true
          slowSqlMillis: 5000
    # 合並多個DruidDataSource的監控數據
#多數據源
mysql-db:
  datasource:
    names: logic,dao
    logic:
      driver-class-name: com.mysql.jdbc.Driver
      url: jdbc:mysql://192.168.1.113:3306/test1?useUnicode=true&characterEncoding=utf-8
      username: root
      password: root
    dao:
      driver-class-name: com.mysql.jdbc.Driver
      url: jdbc:mysql://192.168.1.113:3306/test2?useUnicode=true&characterEncoding=utf-8
      username: root
      password: root

3、配置動態數據源

import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;
/**
 * 動態數據源
 * @author 陳梓平
 * @date 2017/10/9.
 */
public class DynamicDataSource extends AbstractRoutingDataSource {
    @Override
    protected Object determineCurrentLookupKey() {
        return DataSourceHolder.getDataSource();
    }
}

4、配置數據源操作Holder

import java.util.ArrayList;
import java.util.List;
/**
 * 數據源操作
 * @author 陳梓平
 * @date 2017/10/9.
 */
public class DataSourceHolder {
    //線程本地環境
    private static final ThreadLocal<String> contextHolders = new ThreadLocal<String>();
    //數據源列表
    public static List<String> dataSourceIds = new ArrayList<>();
    //設置數據源
    public static void setDataSource(String customerType) {
        contextHolders.set(customerType);
    }
    //獲取數據源
    public static String getDataSource() {
        return (String) contextHolders.get();
    }
    //清除數據源
    public static void clearDataSource() {
        contextHolders.remove();
    }
    /**
     * 判斷指定DataSrouce當前是否存在
     * @param dataSourceId
     * @return
     * @author SHANHY
     * @create  2016年1月24日
     */
    public static boolean containsDataSource(String dataSourceId){
        return dataSourceIds.contains(dataSourceId);
    }
}

5、讀取自定義數據源，並配置

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.MutablePropertyValues;
import org.springframework.beans.PropertyValues;
import org.springframework.boot.autoconfigure.jdbc.DataSourceBuilder;
import org.springframework.boot.bind.RelaxedDataBinder;
import org.springframework.boot.bind.RelaxedPropertyResolver;
import org.springframework.context.EnvironmentAware;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.convert.ConversionService;
import org.springframework.core.convert.support.DefaultConversionService;
import org.springframework.core.env.Environment;
import org.springframework.stereotype.Component;
import javax.sql.DataSource;
import java.util.HashMap;
import java.util.Map;
/**
 * 數據源配置
 * @author 陳梓平
 * @date 2017/10/9.
 */
@Component
@Configuration
public class DynamicDataSourceConfig implements EnvironmentAware {
    private static final Logger logger = LoggerFactory.getLogger(DynamicDataSourceConfig.class);
    // 默認數據源
    private DataSource defaultDataSource;
    // 屬性值
    private PropertyValues dataSourcePropertyValues;
    // 如配置文件中未指定數據源類型，使用該默認值
    private static final Object DATASOURCE_TYPE_DEFAULT = "org.apache.tomcat.jdbc.pool.DataSource";
    private ConversionService conversionService = new DefaultConversionService();
    private Map<String, DataSource> customDataSources = new HashMap<>();
    @Override
    public void setEnvironment(Environment environment) {
        initDefaultDatasource(environment);
        initOtherDatasource(environment);
    }
    private void initOtherDatasource(Environment environment) {
        RelaxedPropertyResolver propertyResolver = new RelaxedPropertyResolver(environment, "mysql-db.datasource.");
        String dsPrefixs = propertyResolver.getProperty("names");
        for (String dsPrefix : dsPrefixs.split(",")) {// 多個數據源
            Map<String, Object> dsMap = propertyResolver.getSubProperties(dsPrefix+".");
            DataSource ds = buildDataSource(dsMap);
            customDataSources.put(dsPrefix, ds);
            dataBinder(ds, environment);
        }
    }
    private void initDefaultDatasource(Environment environment) {
        // 讀取主數據源
        RelaxedPropertyResolver propertyResolver = new RelaxedPropertyResolver(environment, "druid.datasource.");
        Map<String, Object> dsMap = new HashMap<>();
        dsMap.put("type", propertyResolver.getProperty("type"));
        dsMap.put("driver-class-name", propertyResolver.getProperty("driver-class-name"));
        dsMap.put("url", propertyResolver.getProperty("url"));
        dsMap.put("username", propertyResolver.getProperty("username"));
        dsMap.put("password", propertyResolver.getProperty("password"));
        defaultDataSource = buildDataSource(dsMap);
        DataSourceHolder.dataSourceIds.add("ds1");
        dataBinder(defaultDataSource, environment);
    }
    /**
     * 創建DataSource
     * @param dsMap
     * @return
     * @author SHANHY
     * @create 2016年1月24日
     */
    @SuppressWarnings("unchecked")
    public DataSource buildDataSource(Map<String, Object> dsMap) {
        try {
            Object type = dsMap.get("type");
            if (type == null)
                type = DATASOURCE_TYPE_DEFAULT;// 默認DataSource
            Class<? extends DataSource> dataSourceType;
            dataSourceType = (Class<? extends DataSource>) Class.forName((String) type);
            String driverClassName = dsMap.get("driver-class-name").toString();
            String url = dsMap.get("url").toString();
            String username = dsMap.get("username").toString();
            String password = dsMap.get("password").toString();
            DataSourceBuilder factory = DataSourceBuilder.create().driverClassName(driverClassName).url(url)
                    .username(username).password(password).type(dataSourceType);
            return factory.build();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
        return null;
    }
    /**
     * 為DataSource綁定更多數據
     * @param dataSource
     * @param env
     * @author SHANHY
     * @create  2016年1月25日
     */
    private void dataBinder(DataSource dataSource, Environment env){
        RelaxedDataBinder dataBinder = new RelaxedDataBinder(dataSource);
        //dataBinder.setValidator(new LocalValidatorFactory().run(this.applicationContext));
        dataBinder.setConversionService(conversionService);
        dataBinder.setIgnoreNestedProperties(false);//false
        dataBinder.setIgnoreInvalidFields(false);//false
        dataBinder.setIgnoreUnknownFields(true);//true
        if(dataSourcePropertyValues == null){
            Map<String, Object> rpr = new RelaxedPropertyResolver(env, "druid.datasource.").getSubProperties(".");
            Map<String, Object> values = new HashMap<>(rpr);
            // 排除已經設置的屬性
            values.remove("type");
            values.remove("driver-class-name");
            values.remove("url");
            values.remove("username");
            values.remove("password");
            dataSourcePropertyValues = new MutablePropertyValues(values);
        }
        dataBinder.bind(dataSourcePropertyValues);
    }
    @Bean(name = "dataSource")
    public DynamicDataSource dataSource() {
        DynamicDataSource dynamicDataSource = new DynamicDataSource();
        // 默認數據源
        dynamicDataSource.setDefaultTargetDataSource(defaultDataSource);
        // 配置多數據源
        Map<Object, Object> dsMap = new HashMap(5);
        dsMap.put("ds1", defaultDataSource);
        dsMap.putAll(customDataSources);
        for (String key : customDataSources.keySet())
            DataSourceHolder.dataSourceIds.add(key);
        dynamicDataSource.setTargetDataSources(dsMap);
        return dynamicDataSource;
    }
}

6、動態切換關鍵——AOP進行切換

/**
 * 動態數據源註解
 * @author 陳梓平
 * @date 2017/10/9.
 */
@Retention(RetentionPolicy.RUNTIME)
@Target({
        ElementType.METHOD
})
public @interface DS {
    String name() default "ds1";
}
import com.chen.config.dynamicDS.DataSourceHolder;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.After;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.core.annotation.Order;
import org.springframework.stereotype.Component;
/**
 * 設置數據源切面
 * @author 陳梓平
 * @date 2017/10/9.
 */
@Aspect
@Order(-1)// 保證該AOP在@Transactional之前執行
@Component
public class DynamicDataSourceAspect {
    private static final Logger logger = LoggerFactory.getLogger(DynamicDataSourceAspect.class);
    @Before("@annotation(ds)")
    public void changeDataSource(JoinPoint point, DS ds) throws Throwable {
        String dsId = ds.name();
        if (!DataSourceHolder.containsDataSource(dsId)) {
            logger.error("數據源[{}]不存在，使用默認數據源 > {}", ds.name(), point.getSignature());
        } else {
            logger.debug("Use DataSource : {} > {}", ds.name(), point.getSignature());
            DataSourceHolder.setDataSource(ds.name());
        }
    }
    @After("@annotation(ds)")
    public void restoreDataSource(JoinPoint point, DS ds) {
        logger.debug("Revert DataSource : {} > {}", ds.name(), point.getSignature());
        DataSourceHolder.clearDataSource();
    }
}

7、使用

1）、配置mapper

/**
 * @author 陳梓平
 * @date 2017/10/9.
 */
public interface DynamicDSMapper {
    Integer queryJournal();
    String queryUser();
    String queryType();
}
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.chen.mapper.DynamicDSMapper">
    <select id="queryJournal" resultType="java.lang.Integer">
        SELECT uid FROM journal
    </select>
    <select id="queryUser" resultType="java.lang.String">
        SELECT name FROM user
    </select>
    <select id="queryType" resultType="java.lang.String">
        SELECT parent FROM p_type
    </select>
</mapper>

2）、配置service

/**
 * @author 陳梓平
 * @date 2017/10/9.
 */
@Service
public class DynamicServciceImpl implements DynamicServcice {
    @Autowired
    private DynamicDSMapper dynamicDSMapper;
    @DS()
    public Integer ds1() {
        return dynamicDSMapper.queryJournal();
    }
    @DS(name = "logic")
    public String ds2() {
        return dynamicDSMapper.queryUser();
    }
    @DS(name = "dao")
    public String ds3() {
        return dynamicDSMapper.queryType();
    }
}

3）、單元測試調用

/**
 * 多數原測試
 * @author 陳梓平
 * @date 2017/10/9.
 */
@RunWith(SpringRunner.class)
@SpringBootTest
public class TestDynamicDS {
    private Logger logger = LoggerFactory.getLogger(TestDynamicDS.class);
//
    @Autowired
    private DynamicServcice dynamicServcice;
    @Test
    public void test() {
//        Integer integer = dynamicServcice.ds1();
//        logger.info("integer:"+integer);
//        String ds2 = dynamicServcice.ds2();
//        logger.info("ds2:"+ds2);
        String ds3 = dynamicServcice.ds3();
        logger.info("ds3:"+ds3);
    }
}

4）、測試結果

結果

以上為個人經驗，希望能給大傢一個參考，也希望大傢多多支持WalkonNet。

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