配置数据源

如何配置单数据源

搭建项目

主要相关的依赖是h2 和 jdbc, 如果是别的数据库就选别的，入mysql

查看datasource是否配置成功

@springbootapplication
@slf4j
public class datasourcedemoapplication implements commandlinerunner {
	@autowired
	private datasource datasource;

	@autowired
	private jdbctemplate jdbctemplate;

	public static void main(string[] args) {
		springapplication.run(datasourcedemoapplication.class, args);
	}

	@override
	public void run(string... args) throws exception {
		showconnection();
		showdata();
	}

	private void showconnection() throws sqlexception {
		log.info(datasource.tostring());
		connection conn = datasource.getconnection();
		log.info(conn.tostring());
		conn.close();
	}

	private void showdata() {
		jdbctemplate.queryforlist("select * from foo")
				.foreach(row -> log.info(row.tostring()));
	}
}

启动程序控制台输出：

说明spingboot自动帮我们配置好了datasource和jdbctemplate.

当然也可以在配置文件中改变数据源的一些连接信息：

spring.datasource.url=jdbc:h2:mem:testdb
spring.datasource.username=sa
spring.datasource.password=
spring.datasource.hikari.maximumpoolsize=5
spring.datasource.hikari.minimumidle=5
spring.datasource.hikari.idletimeout=600000
spring.datasource.hikari.connectiontimeout=30000
spring.datasource.hikari.maxlifetime=1800000

commandlinerunner解释：在spirngboot启动完成后会执行它的run方法。

如果不是springboot项目，而是spring项目我们需要怎么配置呢？

我们需要手动地配置datasource,transactionmanager以及jdbctemplate这些bean.

@configuration
@enabletransactionmanagement
public class datasourcedemo {
    @autowired
    private datasource datasource;

    public static void main(string[] args) throws sqlexception {
        applicationcontext applicationcontext =
                new classpathxmlapplicationcontext("applicationcontext*.xml");
        showbeans(applicationcontext);
        datasourcedemo(applicationcontext);
    }

    @bean(destroymethod = "close")
    public datasource datasource() throws exception {
        properties properties = new properties();
        properties.setproperty("driverclassname", "org.h2.driver");
        properties.setproperty("url", "jdbc:h2:mem:testdb");
        properties.setproperty("username", "sa");
        return basicdatasourcefactory.createdatasource(properties);
    }

    @bean
    public platformtransactionmanager transactionmanager() throws exception {
        return new datasourcetransactionmanager(datasource());
    }

    private static void showbeans(applicationcontext applicationcontext) {
        system.out.println(arrays.tostring(applicationcontext.getbeandefinitionnames()));
    }

    private static void datasourcedemo(applicationcontext applicationcontext) throws sqlexception {
        datasourcedemo demo = applicationcontext.getbean("datasourcedemo", datasourcedemo.class);
        demo.showdatasource();
    }

    public void showdatasource() throws sqlexception {
        system.out.println(datasource.tostring());
        connection conn = datasource.getconnection();
        system.out.println(conn.tostring());
        conn.close();
    }
}

所以可以看得出springboot帮我们做了很多的配置bean的工作，如果我们没有配置，它会帮我们配置，如果我们自己配置了，那就不会自动配置了

 

如何配置多数据源

配置多数据源的注意事项

　　不同数据源的配置要分开
　　关注每次使⽤用的数据源

　　　　• 有多个datasource时系统如何判断
　　　　• 对应的设施（事务、orm等）如何选择datasource

spring boot中的多数据源配置

　　⼿手⼯工配置两组 datasource 及相关内容
　　与spring boot协同⼯工作（⼆选一）

　　　　• 配置@primary类型的bean
　　　　• 排除spring boot的⾃自动配置
　　　　　　• datasourceautoconfiguration
　　　　　　• datasourcetransactionmanagerautoconfiguration
　　　　　　• jdbctemplateautoconfiguration

package geektime.spring.data.multidatasourcedemo;

import lombok.extern.slf4j.slf4j;
import org.springframework.boot.springapplication;
import org.springframework.boot.autoconfigure.springbootapplication;
import org.springframework.boot.autoconfigure.jdbc.datasourceautoconfiguration;
import org.springframework.boot.autoconfigure.jdbc.datasourceproperties;
import org.springframework.boot.autoconfigure.jdbc.datasourcetransactionmanagerautoconfiguration;
import org.springframework.boot.autoconfigure.jdbc.jdbctemplateautoconfiguration;
import org.springframework.boot.context.properties.configurationproperties;
import org.springframework.context.annotation.bean;
import org.springframework.jdbc.datasource.datasourcetransactionmanager;
import org.springframework.transaction.platformtransactionmanager;

import javax.annotation.resource;
import javax.sql.datasource;

@springbootapplication(exclude = { datasourceautoconfiguration.class,
        datasourcetransactionmanagerautoconfiguration.class,
        jdbctemplateautoconfiguration.class})
@slf4j
public class multidatasourcedemoapplication {

    public static void main(string[] args) {
        springapplication.run(multidatasourcedemoapplication.class, args);
    }

    @bean
    @configurationproperties("foo.datasource")
    public datasourceproperties foodatasourceproperties() {
        return new datasourceproperties();
    }

    @bean
    public datasource foodatasource() {
        datasourceproperties datasourceproperties = foodatasourceproperties();
        log.info("foo datasource: {}", datasourceproperties.geturl());
        return datasourceproperties.initializedatasourcebuilder().build();
    }

    @bean
    @resource
    public platformtransactionmanager footxmanager(datasource foodatasource) {
        return new datasourcetransactionmanager(foodatasource);
    }

    @bean
    @configurationproperties("bar.datasource")
    public datasourceproperties bardatasourceproperties() {
        return new datasourceproperties();
    }

    @bean
    public datasource bardatasource() {
        datasourceproperties datasourceproperties = bardatasourceproperties();
        log.info("bar datasource: {}", datasourceproperties.geturl());
        return datasourceproperties.initializedatasourcebuilder().build();
    }

    @bean
    @resource
    public platformtransactionmanager bartxmanager(datasource bardatasource) {
        return new datasourcetransactionmanager(bardatasource);
    }
}