java代码通过连接池连接mysql数据库的两种方式

-----两个依赖

<!-- https://mvnrepository.com/artifact/org.apache.commons/commons-dbcp2 --> <dependency> <groupId>org.apache.commons</groupId> <artifactId>commons-dbcp2</artifactId> <version>2.7.0</version> </dependency> <!-- https://mvnrepository.com/artifact/com.mchange/c3p0 --> <dependency> <groupId>com.mchange</groupId> <artifactId>c3p0</artifactId> <version>0.9.5.2</version>

方式1—dbcp(要导入这个依赖)

package TestPool; import org.apache.commons.dbcp2.BasicDataSource; import java.sql.Connection; public class TestMysqlDbcp4Pool { public static void main(String[] args) throws Exception { //创建连接池 //dbcp:是针对可以使用jdbc连接的数据库 BasicDataSource basicDataSource = new BasicDataSource(); //指定连接信息 basicDataSource.setDriverClassName("com.mysql.jdbc.Driver"); basicDataSource.setUrl("jdbc:mysql://master:3306/user"); basicDataSource.setUsername("root"); basicDataSource.setPassword("123456"); //连接池在创建的时候创建几个连接 basicDataSource.setInitialSize(2); //最大的连接数 basicDataSource.setMaxIdle(10); //从连接池中获取连接 Connection connection = basicDataSource.getConnection(); //获取活跃的连接池数量 System.out.println(basicDataSource.getNumActive()); //关闭连接，相当于将连接放回连接池 connection.close(); } }

方式2—c3p0(要导入依赖)

package TestPool; import com.mchange.v2.c3p0.ComboPooledDataSource; import java.sql.Connection; public class TestMysqlc3p0Pool { public static void main(String[] args) throws Exception { /** * 创建c3p0连接池 * */ ComboPooledDataSource dataSource = new ComboPooledDataSource(); //指定连接信息 dataSource.setDriverClass("com.mysql.jdbc.Driver"); dataSource.setJdbcUrl("jsbc:mysql://master:3306/user"); dataSource.setUser("root"); dataSource.setPassword("123456"); //连接池在创建的时候创建几个连接 dataSource.setInitialPoolSize(2); //最大的连接数 dataSource.setMaxPoolSize(10); //获取连接 Connection connection = dataSource.getConnection(); //关闭连接 connection.close(); } }