动态查询数据库

只是简单写了一个demo版本，实际应用的时候，可以使用环切，将datasources使用map缓存起来，不需要每次都创建对象。
-----------------maven---------------------

<dependencies>
    <!--   spring常用jar包-->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-jdbc</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
       <dependency>
        <groupId>com.baomidou</groupId>
        <artifactId>mybatis-plus-boot-starter</artifactId>
        <version>2.2.0</version>
    </dependency>
    
    <!--      数据库连接    -->
	   <dependency>
	    <groupId>mysql</groupId>
	    <artifactId>mysql-connector-java</artifactId>
	    <version>8.0.11</version>
	</dependency>
    <!--        spring测试用     -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    	</dependency>
    <!--                  lombok          -->
    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
        <version>1.18.8</version>
        <scope>provided</scope>
    </dependency>
    <!--         自动重启工具         -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-devtools</artifactId>
        <optional>true</optional>
    </dependency>
    <dependency>
        <groupId>com.mchange</groupId>
        <artifactId>c3p0</artifactId>
        <version>0.9.5.2</version>
    </dependency>
    <dependency>
        <groupId>org.apache.commons</groupId>
        <artifactId>commons-lang3</artifactId>
        <version>3.1</version>
    </dependency>
    <dependency>
      <groupId>net.java.dev.jna</groupId>
      <artifactId>jna</artifactId>
      <version>4.1.0</version>
    </dependency>
</dependencies>
<!--                    Spring boot编译插件                 -->
<build>
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
        </plugin>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
            <configuration>
                <fork>true</fork><!-- 如果没有该配置，热部署的devtools不生效 -->
            </configuration>
        </plugin>
    </plugins>
</build>

package com.phone.jdbc;

import java.util.Collections;
import java.util.List;
import java.util.Map;

import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.datasource.DriverManagerDataSource;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RestController;

import com.phone.entity.MyDatasource;

@RestController
public class QueryDa {

/**
 * 动态使用任意数据库查询数据
 * @param myDatasource
 */
@PostMapping("testConnection")
public List<Map<String,Object>> testConnection(@RequestBody MyDatasource myDatasource) {
	DriverManagerDataSource dataSource=new DriverManagerDataSource();
	String url = "jdbc:DBTYPE://IP:PORT/DB?useUnicode=true&characterEncoding=utf-8&serverTimezone=GMT";
	url=url.replace("DBTYPE", myDatasource.getDbType()).replace("IP", myDatasource.getIp()).replace("PORT", myDatasource.getPort()).replace("DB", myDatasource.getDb());
	dataSource.setUsername(myDatasource.getUsername());
	dataSource.setPassword(myDatasource.getPassword());
	dataSource.setDriverClassName(myDatasource.getDriverClassName());
	dataSource.setUrl(url);
	JdbcTemplate jdbcTemplate=new JdbcTemplate();
	jdbcTemplate.setDataSource(dataSource);
	String sql=myDatasource.getSql();
	List<Map<String,Object>> queryForList = jdbcTemplate.queryForList(sql);
	if(queryForList==null) {
		return Collections.EMPTY_LIST;
	}
	for (Map<String, Object> map : queryForList) {
		System.out.println("-------------------");
		for (String key : map.keySet()) {
			Object object = map.get(key);
			System.out.println("key:"+key+"|value:"+object);
		}
	}
	return queryForList;
}

}

---

package com.phone.entity;

import lombok.Data;

@Data
public class MyDatasource {

private String driverClassName;

private String db;

private String username;

private String password;

private String ip;

private String port;

private String sql;

private String dbType;

}