Java – connection using connectionpooldatasource

Connect to the database I need I intend to use the connectionpooldatasource class But how to use this instance to set up details about the database name (to which I want it to connect) Please help solve this problem

Solution

Try reading this document and example

edit

The example has just been modified from the link above

Preparation steps: – download MySQL server – download MySQL Java driver – download Apache commons pool – download commons DBCP – open a MySQL client like MySQL workbench and use the next script to create a database

delimiter $$

CREATE DATABASE `test_stackoverflow` /*!40100 DEFAULT CHARACTER SET utf8 */$$

delimiter $$

CREATE TABLE `test_table` (
  `idtest_table` int(11) NOT NULL,`test_field` varchar(45) DEFAULT NULL,PRIMARY KEY (`idtest_table`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8$$

INSERT INTO `test_stackoverflow`.`test_table` (`idtest_table`,`test_field`) VALUES (1,'test1');
INSERT INTO `test_stackoverflow`.`test_table` (`idtest_table`,`test_field`) VALUES (2,'test2');

>Create a java project and add it to the classpath, myscl connector, pool and DBCP (you just need to download all these jars)

Add next course

import org.apache.commons.dbcp.cpdsadapter.DriverAdapterCPDS;
import org.apache.commons.dbcp.datasources.SharedPoolDataSource;

import javax.sql.DataSource;
import java.sql.Connection;
import java.sql.sqlException;

/**
 * @author Sergii.Zagriichuk
 */
public class Pool {
    private static DataSource ds;

    static {
        DriverAdapterCPDS cpds = new DriverAdapterCPDS();
        try {
            cpds.setDriver("com.MysqL.jdbc.Driver");
        } catch (ClassNotFoundException e) {
            e.printStackTrace();  //To change body of catch statement use File | Settings | File Templates.
        }
        cpds.setUrl("jdbc:MysqL://localhost:3306/test_stackoverflow");
        cpds.setUser("root");
        cpds.setPassword("root");

        SharedPoolDataSource tds = new SharedPoolDataSource();
        tds.setConnectionPoolDataSource(cpds);
        tds.setMaxActive(10);
        tds.setMaxWait(50);

        ds = tds;
    }

    public static Connection getConnection() throws sqlException {
        return ds.getConnection();
    }
}

The user name and password should be changed to your database user / password

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.sqlException;
import java.sql.Statement;

public class MainClass {
    public static void main(String[] args) {
        Connection connection = null;
        Statement statement = null;
        ResultSet resultSet = null;

        try {
            connection = Pool.getConnection();
            // Do work with connection
            statement = connection.createStatement();
            String selectEmployeessql = "select * from test_table";
            resultSet = statement.executeQuery(selectEmployeessql);

            while (resultSet.next()) {
                printTestTable(resultSet);
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (resultSet != null) {
                try {
                    resultSet.close();
                } catch (sqlException e) {
                } // nothing we can do
            }
            if (statement != null) {
                try {
                    statement.close();
                } catch (sqlException e) {
                } // nothing we can do
            }
            if (connection != null) {
                try {
                    connection.close();
                } catch (sqlException e) {
                } // nothing we can do
            }
        }
    }

    private static void printTestTable(ResultSet resultSet) throws sqlException {
        System.out.print(resultSet.getInt("idtest_table")+",");
        System.out.print(resultSet.getString("test_field"));
    }

}

Just run the main method and you'll see the test values printed to the console!