Java JDBC Druid

版权声明：本文为作者创作，转载请注明出处:http://blog.csdn.net/claroja，如有商业用途请联系QQ：63183535。 https://blog.csdn.net/claroja/article/details/89953957

1.添加jar包
druid-1.0.9.jar
postgresql-42.2.5.jar
2.添加配置文件，配置文件可以随意路径
druid.properties
内容如下：

driverClassName=org.postgresql.Driver
url=jdbc:postgresql://localhost:5432/postgres
username=postgres
password=postgres
initialSize=5
maxActive=10
maxWait=3000

3.编写代码

package druid;

import com.alibaba.druid.pool.DruidDataSourceFactory;

import javax.sql.DataSource;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.Properties;

public class DruidDemo {
    public static void main(String[] args) throws Exception {
        Properties pro = new Properties();
        InputStream is = DruidDemo.class.getClassLoader().getResourceAsStream("druid.properties");
        pro.load(is);
        DataSource ds = DruidDataSourceFactory.createDataSource(pro);

        Connection conn = ds.getConnection();
        System.out.println(conn);

        String sql5 = "select * from account where id = ?";
        PreparedStatement pstmt = conn.prepareStatement(sql5);//pstmt 效率高可以防止注入
        pstmt.setInt(1,1);//给问号赋值
        ResultSet res2 = pstmt.executeQuery();
        res2.next();
        String name2 = res2.getString("NAME");
        System.out.print(name2+"\n");

        res2.close();
        pstmt.close();
        conn.close();//这里是归还连接，而不是关闭

    }
}