springboot 集成多數據源學習02——使用spring自帶的JdbcTemplate實現

#1.依賴

 <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
``

2.配置數據源

package com.example.jdbctem.jdbc;

import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.jdbc.DataSourceBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.jdbc.core.JdbcTemplate;

import javax.sql.DataSource;

@Configuration
public class DataSourceConfig {
    @Bean(name = "primaryDataSource")
    @ConfigurationProperties("spring.datasource.primary")
    public DataSource primaryDataSource() {
        return DataSourceBuilder.create().build();
    }

    @Primary
    @Bean(name = "secondaryDataSource")
    @ConfigurationProperties("spring.datasource.secondary")
    public DataSource secondaryDataSource() {
        return DataSourceBuilder.create().build();
    }


    /**
     * @param dataSource
     * @return
     * @Bean明確地指示了一種方法，什麼方法呢——產生一個bean的方法， 並且交給Spring容器管理；從這我們就明白了爲啥@Bean是放在方法的註釋上了，
     * 因爲它很明確地告訴被註釋的方法，你給我產生一個Bean，然後交給Spring容器，
     * 實現依賴注入
     */
    @Bean(name = "primaryJdbcTemplate")
    public JdbcTemplate primaryTemplate(@Qualifier("primaryDataSource") DataSource dataSource) {
        return new JdbcTemplate(dataSource);
    }

    @Bean(name = "secondaryJdbcTemplate")
    public JdbcTemplate secondaryTemplate(@Qualifier("secondaryDataSource") DataSource dataSource) {
        return new JdbcTemplate(dataSource);
    }
}

3.

package com.example.jdbctem.jdbc;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Component;

import java.util.List;

@Component
public class UserImp2 implements UserDao {
    @Autowired
    @Qualifier("secondaryJdbcTemplate")
    private JdbcTemplate jdbcTemplate;

    @Override
    public List<UserBean> getAll() {
        return jdbcTemplate.query("select * from test", (resultSet, i) -> {
            UserBean userBean = new UserBean();
            userBean.setId(resultSet.getInt("id"));
            userBean.setName(resultSet.getString("name"));
            return userBean;
        });
    }
}

package com.example.jdbctem.jdbc;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Component;

import java.util.List;

@Component
public class UserImp implements UserDao {
    @Autowired
    @Qualifier("primaryJdbcTemplate")
    private JdbcTemplate jdbcTemplate;

    @Override
    public List<UserBean> getAll() {
        return jdbcTemplate.query("select * from db", (resultSet, i) -> {
            UserBean userBean = new UserBean();
            userBean.setId(resultSet.getInt("id"));
            userBean.setName(resultSet.getString("name"));
            return userBean;
        });
    }
}