Database connection pool Druid

Druid

jar Package download

Enter official website https://repo1.maven.org/maven2/com/alibaba/druid/
Choose the version , Click enter

choice jar package （.jar）

Implementation steps

• Import jar package
• Define configuration file
  （1） yes properties Formal
  （2） Can be called any name , It can be placed in any directory
• Load profile Properties
• Get database connection pool ： Get through the factory class DruidDataSourceFactory
• Get the connection ：getConnection

The configuration file

driverClassName=com.mysql.cj.jdbc.Driver
url=jdbc:mysql://localhost:3306/jdbc
username=root
password=root
initialSize=5
maxActive=10
maxWait=3000

package druid;

import com.alibaba.druid.pool.DruidDataSourceFactory;

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

public class DruidDemo {
    
    public static void main(String[] args) throws Exception {
    
        // Load profile 
        Properties pro = new Properties();
        InputStream is = DruidDemo.class.getClassLoader().getResourceAsStream("druid.properties");
        pro.load(is);
        // Get connection pool object 
        DataSource ds = DruidDataSourceFactory.createDataSource(pro);
        // Get the connection 
        Connection conn = ds.getConnection();
        System.out.println(conn);
    }
}

Tool class

• Definition JDBCUtils
• Provide static code block loading configuration file , Initialize connection pool object
• Provide methods
  （1） Get the connection method ： Get the connection through the database connection pool
  （2） Release resources
  （3） Get connection pool

package druid.utils;

import com.alibaba.druid.pool.DruidDataSourceFactory;

import javax.sql.DataSource;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Properties;

public class  JDBCUtils {
    
    // Define member variables 
    private static DataSource ds;

    static {
    
        // Load profile 
        Properties pro = new Properties();
        try {
    
            pro.load(JDBCUtils.class.getClassLoader().getResourceAsStream("druid.properties"));
            ds = DruidDataSourceFactory.createDataSource(pro);
        } catch (Exception e) {
    
            e.printStackTrace();
        }
    }

    // Get the connection 
    public static Connection getConnection() throws SQLException {
    
        return ds.getConnection();
    }

    // Release resources 
    public static void close(Statement stmt, Connection conn){
    
        if (stmt != null){
    
            try {
    
                stmt.close();
            } catch (Exception e) {
    
                e.printStackTrace();
            }
        }
        if (conn != null){
    
            try {
    
                conn.close();
            } catch (Exception e) {
    
                e.printStackTrace();
            }
        }
    }

    public static void close(ResultSet rs, Statement stmt, Connection conn){
    
        if (rs != null){
    
            try {
    
                rs.close();
            } catch (Exception e) {
    
                e.printStackTrace();
            }
        }
        close(stmt, conn);
    }

    // Get connection pool 
    public static DataSource getDataSource(){
    
        return ds; 
    }
}