Maven下Druid连接池配置及使用全过程

处理Maven下Druid连接池配置及使用全过程这类问题时，先确认目标场景，再按步骤核对配置或玩法细节。

1.在pom.xml中导入架包及jdbc架包

<dependency>          <groupId>com.alibaba</groupId>          <artifactId>druid</artifactId>          <version>1.1.6</version>    </dependency>    <dependency>      <groupId>mysql</groupId>      <artifactId>mysql-connector-java</artifactId>      <version>8.0.17</version>    </dependency>

2.定义配置文件

（这里的文件时properties格式的，可以放到任意位置）

druid.properties

driverClassName=com.mysql.jdbc.Driverurl=jdbc:mysql://127.0.0.1:3306/db1?serverTimezone=Asia/Shanghaiusername=rootpassword=root#初始化连接数量initialSize=5#最大连接数maxActive=10#最大等待时间maxWait=3000

3.测试

需要先加载配置文件

import com.alibaba.druid.pool.DruidDataSourceFactory;import javax.sql.DataSource;import java.io.IOException;import java.io.InputStream;import java.sql.Connection;import java.util.Properties;public class DruidDemo {    public static void main(String[] args) throws Exception {        //1.加载配置文件        Properties pro = new Properties();        InputStream is = DruidDemo.class.getClassLoader().getResourceAsStream("druid.properties");        pro.load(is);        //2.获取连接池对象        DataSource ds = DruidDataSourceFactory.createDataSource(pro);        //3.获取连接        Connection conn = ds.getConnection();        System.out.println(conn);    }}

4.结果

出现如下图即成功

5.简化步骤

将一些操作封装到一个工具类中

JDBCUtils.java

import com.alibaba.druid.pool.DruidDataSourceFactory;import javax.sql.DataSource;import java.io.IOException;import java.sql.Connection;import java.sql.ResultSet;import java.sql.SQLException;import java.sql.Statement;import java.util.Properties;/*Druid连接池的工具类 */public class JDBCUtils {    //1.定义成员变量 DataSource    private static DataSource ds;    static {        //1.加载配置文件        Properties pro = new Properties();        try {            pro.load(JDBCUtils.class.getClassLoader().getResourceAsStream("druid.properties"));            //获取DataSource            ds = DruidDataSourceFactory.createDataSource(pro);        } catch (IOException e) {            e.printStackTrace();        } catch (Exception e) {            e.printStackTrace();        }    }    //获取连接    public static Connection getConnection() throws SQLException {        return ds.getConnection();    }    //释放资源    public static void close(Statement stmt,Connection conn){        if (stmt!=null) {            try {                stmt.close();            } catch (Exception e) {                System.out.println(e.getMessage());            }        }        if (conn!=null){            try {                conn.close();//归还连接            } catch (Exception e) {                System.out.println(e.getMessage());            }        }    }    public static void close(ResultSet rs, Statement stmt, Connection conn){        if (rs!=null) {            try {                rs.close();            } catch (Exception e) {                System.out.println(e.getMessage());            }        }        if (stmt!=null) {            try {                stmt.close();            } catch (Exception e) {                System.out.println(e.getMessage());            }        }        if (conn!=null){            try {                conn.close();//归还连接            } catch (Exception e) {                System.out.println(e.getMessage());            }        }    }    //获取连接池    public static DataSource getDataSource(){        return ds;    }}

测试工具类：DruidTest.java

import java.sql.Connection;import java.sql.PreparedStatement;import java.sql.SQLException;//测试工具类public class DruidTest {    public static void main(String[] args) throws SQLException {        //给dept表添加一条记录        //1.获取连接        Connection conn = JDBCUtils.getConnection();        //2.定义sql        String sql = "insert into dept values(?,?,?)";        //3.获取邮差对象        PreparedStatement ps = conn.prepareStatement(sql);        //4.给？赋值        ps.setInt(1,50);        ps.setString(2,"HAHAHAH");        ps.setString(3,"CHINA");        //5.执行sql        ps.executeUpdate();    }}

结果：插入成功

总结