Implement Connection pooling in JDBC using apache dbcp [duplicate]

问题

Is this Good Code to implement pooling? I want to implement this in my project which has 30 threads operating concurrently and each thread requires more than four connection for each request? Does this code work?

    import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

import java.sql.Connection;
import java.sql.SQLException;
import org.apache.commons.dbcp.BasicDataSource;

/**
 *
 * @author
 * taher_JAVAHUNTER
 */

    public class JDBCHelper {

        private final static String username = "root";
        private final static String password = "";
        private final static String url = "jdbc:mysql://localhost:3306/treamisdemo";
        public static Connection connection = null;
        public static int connectionCount = 0;
    //    public JDBCHelper(boolean setCon) {
    //        try {
    //            setConnectionTest();
    //        } catch (Exception e) {
    //            System.out.println("Error in Connection:" + e.toString());
    //        }
    //    }
        public static BasicDataSource dataSource;

        public static Connection getConnection() throws SQLException {
            try {
                if (dataSource == null) {
                    dataSource = new BasicDataSource();
                    String driver = "com.mysql.jdbc.Driver";
                    try {
                        dataSource.setDriverClassName(driver);
                        dataSource.setUrl(url);
                        dataSource.setUsername(username);
                        dataSource.setPassword(password);
                        dataSource.setMaxActive(100);
                        dataSource.setMaxWait(10000);
                        dataSource.setMaxIdle(10);
                        if (connection == null || connection.isClosed()) {
                            System.out.println(" requeition CONNECTION WITH FIRST SERVER.");
                            connection = dataSource.getConnection();
                            connectionCount++;
                        }
                    } catch (SQLException e) {
                        System.out.println("***Connection Requisition*** Could not connect to the database msg :" + e.getMessage());
                    }
                } else {
                    connection = dataSource.getConnection();
                    connectionCount++;
                }
            } catch (Exception e) {
                System.out.println("open connection exception" + e);
            }
            return connection;
        }

        public static void close(ResultSet c) {
            try {
                if (c != null) {
                    c.close();
                }
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }

        public static void close(Statement c) {
            try {
                if (c != null) {
                    c.close();
                }
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }

        public static void close(Connection c) {
            try {
                if (c != null) {
                    c.close();
                }
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }

}

回答1:

I would not recommend this approach. You are basically creating a connection and hanging on it it. I'm not in love with your pattern, but something like this would be better:

public class DataTransaction {
   private final static BasicDataSource dataSource;

   static {
      dataSource = new BasicDataSource();
      dataSource.setDriverClassName("com.mysql.jdbc.Driver");
      dataSource.setUrl("jdbc:mysql://127.0.0.1:3306/registrationtest");
      dataSource.setUsername("root");
      dataSource.setPassword("root");
      dataSource.setMaxActive(100);
      dataSource.setMaxWait(10000);
      dataSource.setMaxIdle(10);
   }

   private DataTransaction() {
   }

   public static DataSource getDataSource() {
      return dataSource;
   }
}

Further, I would not hardcode any of the DataSource parameters, but rather initialize the DataSource from a properties file.

来源：https://stackoverflow.com/questions/20016046/implement-connection-pooling-in-jdbc-using-apache-dbcp

标签

java

mysql

jdbc

apache-commons-dbcp