基于AOP的動态資料源
在開發中,往往一個資料源不能夠滿足開發的需求,需要動态的切換資料源以滿足線上環境的需求。
本文實作的代碼類後,隻需要配置好資料源就可以直接通過注解使用,簡單友善。
一配置二使用
- 啟動類注冊動态資料源
- 配置檔案中配置多個資料源
- 在需要的方法上使用注解指定資料源
DynamicDataSourceRegister
啟動時加入動态資料源注冊:
@SpringBootApplication@Import({DynamicDataSourceRegister.class}) // 注冊動态多資料源public class SpringBootSampleApplication { // 省略其他代碼}
然後配置多個資料源屬性
# 主資料源,預設的spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/test
spring.datasource.username=root
spring.datasource.password=123456# 更多資料源custom.datasource.names=ds1,ds2
custom.datasource.ds1.driver-class-name=com.mysql.jdbc.Driver
custom.datasource.ds1.url=jdbc:mysql://localhost:3306/test1
custom.datasource.ds1.username=root
custom.datasource.ds1.password=123456
custom.datasource.ds2.driver-class-name=com.mysql.jdbc.Driver
custom.datasource.ds2.url=jdbc:mysql://localhost:3306/test2
custom.datasource.ds2.username=root
custom.datasource.ds2.password=123456
如何使用
package org.springboot.sample.service;import java.sql.ResultSet;import java.sql.SQLException;import java.util.List;import org.springboot.sample.datasource.TargetDataSource;import org.springboot.sample.entity.Student;import org.springboot.sample.mapper.StudentMapper;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.jdbc.core.JdbcTemplate;import org.springframework.jdbc.core.RowMapper;import org.springframework.stereotype.Service;/**
* Student Service
*
* @author 單紅宇(365384722)
* @myblog http://blog.net/catoop/
* @create 2016年1月12日
*/@Servicepublic class StudentService { @Autowired
private JdbcTemplate jdbcTemplate; // MyBatis的Mapper方法定義接口
@Autowired
private StudentMapper studentMapper; @TargetDataSource(name="ds2") public List<Student> likeName(String name){ return studentMapper.likeName(name);
} public List<Student> likeNameByDefaultDataSource(String name){ return studentMapper.likeName(name);
} /**
* 不指定資料源使用預設資料源
*
* @return
* @author SHANHY
* @create 2016年1月24日
*/
public List<Student> getList(){
String sql = "SELECT ID,NAME,SCORE_SUM,SCORE_AVG, AGE FROM STUDENT"; return (List<Student>) jdbcTemplate.query(sql, new RowMapper<Student>(){ @Override
public Student mapRow(ResultSet rs, int rowNum) throws SQLException {
Student stu = new Student();
stu.setId(rs.getInt("ID"));
stu.setAge(rs.getInt("AGE"));
stu.setName(rs.getString("NAME"));
stu.setSumScore(rs.getString("SCORE_SUM"));
stu.setAvgScore(rs.getString("SCORE_AVG")); return stu;
}
});
} /**
* 指定資料源
*
* @return
* @author SHANHY
* @create 2016年1月24日
*/
@TargetDataSource(name="ds1") public List<Student> getListByDs1(){
String sql = "SELECT ID,NAME,SCORE_SUM,SCORE_AVG, AGE FROM STUDENT"; return (List<Student>) jdbcTemplate.query(sql, new RowMapper<Student>(){ @Override
public Student mapRow(ResultSet rs, int rowNum) throws SQLException {
Student stu = new Student();
stu.setId(rs.getInt("ID"));
stu.setAge(rs.getInt("AGE"));
stu.setName(rs.getString("NAME"));
stu.setSumScore(rs.getString("SCORE_SUM"));
stu.setAvgScore(rs.getString("SCORE_AVG")); return stu;
}
});
} /**
* 指定資料源
*
* @return
* @author SHANHY
* @create 2016年1月24日
*/
@TargetDataSource(name="ds2") public List<Student> getListByDs2(){
String sql = "SELECT ID,NAME,SCORE_SUM,SCORE_AVG, AGE FROM STUDENT"; return (List<Student>) jdbcTemplate.query(sql, new RowMapper<Student>(){ @Override
public Student mapRow(ResultSet rs, int rowNum) throws SQLException {
Student stu = new Student();
stu.setId(rs.getInt("ID"));
stu.setAge(rs.getInt("AGE"));
stu.setName(rs.getString("NAME"));
stu.setSumScore(rs.getString("SCORE_SUM"));
stu.setAvgScore(rs.getString("SCORE_AVG")); return stu;
}
});
}
}
一般是在IMPL中實作。
五個類
将下面幾個類放到Spring Boot項目中。
- DynamicDataSource.java
- DynamicDataSourceAspect.java
- DynamicDataSourceContextHolder.java
- DynamicDataSourceRegister.java
- TargetDataSource.java
DynamicDataSource
import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;/**
* 動态資料源
*
* @author 單紅宇(365384722)
* @myblog http://blog.net/catoop/
* @create 2016年1月22日
*/public class DynamicDataSource extends AbstractRoutingDataSource { @Override
protected Object determineCurrentLookupKey() { return DynamicDataSourceContextHolder.getDataSourceType();
}
}
DynamicDataSourceAspect
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.stereotype.Component;/**
* 切換資料源Advice
*
* @author 單紅宇(365384722)
* @myblog http://blog.net/catoop/
* @create 2016年1月23日
*/@Aspect@Order(-1)// 保證該AOP在@Transactional之前執行@Componentpublic class DynamicDataSourceAspect { private static final Logger logger = LoggerFactory.getLogger(DynamicDataSourceAspect.class); @Before("@annotation(ds)")
public void changeDataSource(JoinPoint point, TargetDataSource ds) throws Throwable {
String dsId = ds.name(); if (!DynamicDataSourceContextHolder.containsDataSource(dsId)) {
logger.error("資料源[{}]不存在,使用預設資料源 > {}", ds.name(), point.getSignature());
} else {
logger.debug("Use DataSource : {} > {}", ds.name(), point.getSignature());
DynamicDataSourceContextHolder.setDataSourceType(ds.name());
}
} @After("@annotation(ds)")
public void restoreDataSource(JoinPoint point, TargetDataSource ds) {
logger.debug("Revert DataSource : {} > {}", ds.name(), point.getSignature());
DynamicDataSourceContextHolder.clearDataSourceType();
}
}
DynamicDataSourceContextHolder
import java.util.ArrayList;import java.util.List;public class DynamicDataSourceContextHolder { private static final ThreadLocal<String> contextHolder = new ThreadLocal<String>(); public static List<String> dataSourceIds = new ArrayList<>(); public static void setDataSourceType(String dataSourceType) {
contextHolder.set(dataSourceType);
} public static String getDataSourceType() { return contextHolder.get();
} public static void clearDataSourceType() {
contextHolder.remove();
} /**
* 判斷指定DataSrouce目前是否存在
*
* @param dataSourceId
* @return
* @author SHANHY
* @create 2016年1月24日
*/
public static boolean containsDataSource(String dataSourceId){ return dataSourceIds.contains(dataSourceId);
}
}
DynamicDataSourceRegister
import java.util.HashMap;import java.util.Map;import javax.sql.DataSource;import org.slf4j.Logger;import org.slf4j.LoggerFactory;import org.springframework.beans.MutablePropertyValues;import org.springframework.beans.PropertyValues;import org.springframework.beans.factory.support.BeanDefinitionRegistry;import org.springframework.beans.factory.support.GenericBeanDefinition;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.ImportBeanDefinitionRegistrar;import org.springframework.core.convert.ConversionService;import org.springframework.core.convert.support.DefaultConversionService;import org.springframework.core.env.Environment;import org.springframework.core.type.AnnotationMetadata;/**
* 動态資料源注冊<br/>
* 啟動動态資料源請在啟動類中(如SpringBootSampleApplication)
* 添加 @Import(DynamicDataSourceRegister.class)
*
* @author 單紅宇(365384722)
* @myblog http://blog.net/catoop/
* @create 2016年1月24日
*/public class DynamicDataSourceRegister
implements ImportBeanDefinitionRegistrar, EnvironmentAware {
private static final Logger logger = LoggerFactory.getLogger(DynamicDataSourceRegister.class);
private ConversionService conversionService = new DefaultConversionService();
private PropertyValues dataSourcePropertyValues; // 如配置檔案中未指定資料源類型,使用該預設值
private static final Object DATASOURCE_TYPE_DEFAULT = "org.apache.tomcat.jdbc.pool.DataSource"; // private static final Object DATASOURCE_TYPE_DEFAULT =
// "com.zaxxer.hikari.HikariDataSource";
// 資料源
private DataSource defaultDataSource;
private Map<String, DataSource> customDataSources = new HashMap<>(); @Override
public void registerBeanDefinitions(AnnotationMetadata importingClassMetadata, BeanDefinitionRegistry registry) { Map<Object, Object> targetDataSources = new HashMap<Object, Object>(); // 将主資料源添加到更多資料源中
targetDataSources.put("dataSource", defaultDataSource);
DynamicDataSourceContextHolder.dataSourceIds.add("dataSource"); // 添加更多資料源
targetDataSources.putAll(customDataSources); for (String key : customDataSources.keySet()) {
DynamicDataSourceContextHolder.dataSourceIds.add(key);
} // 建立DynamicDataSource
GenericBeanDefinition beanDefinition = new GenericBeanDefinition();
beanDefinition.setBeanClass(DynamicDataSource.class);
beanDefinition.setSynthetic(true);
MutablePropertyValues mpv = beanDefinition.getPropertyValues();
mpv.addPropertyValue("defaultTargetDataSource", defaultDataSource);
mpv.addPropertyValue("targetDataSources", targetDataSources);
registry.registerBeanDefinition("dataSource", beanDefinition);
logger.info("Dynamic DataSource Registry");
} /** * 建立DataSource * * @param type * @param driverClassName * @param url * @param username * @param password * @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;// 預設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;
} /** * 加載多資料源配置 */
@Override
public void setEnvironment(Environment env) {
initDefaultDataSource(env);
initCustomDataSources(env);
} /** * 初始化主資料源 * * @author SHANHY * @create 2016年1月24日 */
private void initDefaultDataSource(Environment env) { // 讀取主資料源
RelaxedPropertyResolver propertyResolver = new RelaxedPropertyResolver(env, "spring.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);
dataBinder(defaultDataSource, env);
} /** * 為DataSource綁定更多資料 * * @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, "spring.datasource").getSubProperties("."); Map<String, Object> values = new HashMap<>(rpr); // 排除已經設定的屬性
values.remove("type");
values.remove("driver-class-name");
values.remove("url");
values.remove("username");
values.remove("password");
dataSourcePropertyValues = new MutablePropertyValues(values);
}
dataBinder.bind(dataSourcePropertyValues);
} /** * 初始化更多資料源 * * @author SHANHY * @create 2016年1月24日 */
private void initCustomDataSources(Environment env) { // 讀取配置檔案擷取更多資料源,也可以通過defaultDataSource讀取資料庫擷取更多資料源
RelaxedPropertyResolver propertyResolver = new RelaxedPropertyResolver(env, "custom.datasource."); String dsPrefixs = propertyResolver.getProperty("names"); for (String dsPrefix : dsPrefixs.split(",")) {// 多個資料源
Map<String, Object> dsMap = propertyResolver.getSubProperties(dsPrefix + ".");
DataSource ds = buildDataSource(dsMap);
customDataSources.put(dsPrefix, ds);
dataBinder(ds, env);
}
}
}
import java.lang.annotation.Documented;import java.lang.annotation.ElementType;import java.lang.annotation.Retention;import java.lang.annotation.RetentionPolicy;import java.lang.annotation.Target;/**
* 在方法上使用,用于指定使用哪個資料源
*
* @author 單紅宇(365384722)
* @myblog http://blog.csdn.net/catoop/
* @create 2016年1月23日
*/@Target({ ElementType.METHOD, ElementType.TYPE })
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface TargetDataSource { String name();
}