Spring中的动态数据源解读

jdbc:mysql://localhost:3306/t_db1?useSSL=false&allowPublicKeyRetrieval=true&serverTimezone=UTC

package datasource.dynamic;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.datasource.DriverManagerDataSource;
import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;
import javax.sql.DataSource;
import java.util.HashMap;
import java.util.Map;
@Configuration
public class Config {
	@Bean
	public DriverManagerDataSource dataSource1(){
		String url = "jdbc:mysql://localhost:3306/t_db1?useSSL=false&allowPublicKeyRetrieval=true&serverTimezone=UTC";
		String userName = "root";
		String password = "123456";
		return new DriverManagerDataSource(url,userName,password);
	}
	@Bean
	public DriverManagerDataSource dataSource2(){
		String url = "jdbc:mysql://localhost:3306/t_db2?useSSL=false&allowPublicKeyRetrieval=true&serverTimezone=UTC";
		String userName = "root";
		String password = "123456";
		return new DriverManagerDataSource(url,userName,password);
	}
	@Bean
	public DriverManagerDataSource dataSource3(){
		String url = "jdbc:mysql://localhost:3306/t_db3?useSSL=false&allowPublicKeyRetrieval=true&serverTimezone=UTC";
		String userName = "root";
		String password = "123456";
		return new DriverManagerDataSource(url,userName,password);
	}
	@Bean
	public MyDynamicDataSource dynamicDataSource(Map<String,DriverManagerDataSource> map){
		HashMap<Object, Object> original = new HashMap<>(map);
		MyDynamicDataSource myDynamicDataSource = new MyDynamicDataSource();
		myDynamicDataSource.setTargetDataSources(original);
		return myDynamicDataSource;
	}
	@Bean
	public JdbcTemplate jdbcTemplate(AbstractRoutingDataSource dataSource){
		return new JdbcTemplate(dataSource);
	}
}

package datasource.dynamic;
import org.springframework.util.Assert;
public class DataSourceKeyHolder {
	private static final ThreadLocal<String> keyHolder = new ThreadLocal<>();
	public static void setKey(String key) {
		keyHolder.remove();
		keyHolder.set(key);
	}
	public static String getKey() {
		String s = keyHolder.get();
		Assert.notNull(s, "key 不能为空");
		return s;
	}
	public static void clear(){
		keyHolder.remove();
	}
}

package datasource.dynamic;
import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;
public class MyDynamicDataSource extends AbstractRoutingDataSource {
	@Override
	protected Object determineCurrentLookupKey() {
		return DataSourceKeyHolder.getKey();
	}
}

public class TestBean {
	private Integer id;
	private String name;
	private Double age;
	public Integer getId() {
		return id;
	}
	public void setId(Integer id) {
		this.id = id;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public Double getAge() {
		return age;
	}
	public void setAge(Double age) {
		this.age = age;
	}
	@Override
	public String toString() {
		return "TestBean{" +
				"id=" + id +
				", name='" + name + '\'' +
				", age=" + age +
				'}';
	}
}

-- auto-generated definition
create table t_test
(
    id   int auto_increment
        primary key,
    name text   null,
    age  double null
);

package datasource.dynamic;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;
public class MainTest {
	public static void main(String[] args) {
		try {
			AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(Config.class);
			JdbcTemplate jdbcTemplate = context.getBean(JdbcTemplate.class); // 这里从头到尾用的都是一个JdbcTemplate
			dataSource1(jdbcTemplate); // 动态数据源1
			dataSource2(jdbcTemplate);// 动态数据源2
			dataSource3(jdbcTemplate);// 动态数据源3
		}catch (Exception e){
			e.printStackTrace();
		}
	}
	public static void dataSource1(	JdbcTemplate jdbcTemplate ){
		DataSourceKeyHolder.setKey("dataSource1");
		try {
			TestBean testBean = jdbcTemplate.queryForObject("select * from t_test where id=?", new BeanPropertyRowMapper<>(TestBean.class), 1);
			System.out.println(testBean);
		}finally {
			DataSourceKeyHolder.clear();
		}
	}
	public static void dataSource2(	JdbcTemplate jdbcTemplate ){
		DataSourceKeyHolder.setKey("dataSource2");
		try {
			TestBean testBean = jdbcTemplate.queryForObject("select * from t_test where id=?", new BeanPropertyRowMapper<>(TestBean.class), 1);
			System.out.println(testBean);
		}finally {
			DataSourceKeyHolder.clear();
		}
	}
	public static void dataSource3(	JdbcTemplate jdbcTemplate ){
		DataSourceKeyHolder.setKey("dataSource3");
		try {
			TestBean testBean = jdbcTemplate.queryForObject("select * from t_test where id=?", new BeanPropertyRowMapper<>(TestBean.class), 1);
			System.out.println(testBean);
		}finally {
			DataSourceKeyHolder.clear();
		}
	}
}