java 数据库连接池和普通连接 对比

自由自在，闲话省略

包：c3p0-***.jar

mchange-commons-java-**.jar

ojdba.jar

mysql-connector.jaava-**bin.jar

ConnectionManager

package com.adao.c3p0;

import java.beans.PropertyVetoException;
import java.sql.Connection;
import java.sql.SQLException;
import com.mchange.v2.c3p0.ComboPooledDataSource;

public final class ConnectionManager {
    //使用单利模式创建数据库连接池
    private static ConnectionManager instance;
    private static ComboPooledDataSource dataSource;
  
    private ConnectionManager() throws SQLException, PropertyVetoException {
        dataSource = new ComboPooledDataSource();
  
        dataSource.setUser("coll_platform");     //用户名
        dataSource.setPassword("coll_platform"); //密码
        dataSource.setJdbcUrl("jdbc:oracle:thin:@192.168.127.156:1521:ORCL");//数据库地址
        dataSource.setDriverClass("oracle.jdbc.driver.OracleDriver");
        dataSource.setInitialPoolSize(5); //初始化连接数
        dataSource.setMinPoolSize(1);//最小连接数
        dataSource.setMaxPoolSize(10);//最大连接数
        dataSource.setMaxStatements(50);//最长等待时间
        dataSource.setMaxIdleTime(60);//最大空闲时间，单位毫秒
    }
  
    public static final ConnectionManager getInstance() {
        if (instance == null) {
            try {
                instance = new ConnectionManager();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        return instance;
    }
  
    public synchronized final Connection getConnection() {
        Connection conn = null;
        try {
            conn = dataSource.getConnection();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return conn;
    }
}

ConnectionDemo

package com.adao.c3p0;

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

import com.mysql.jdbc.jdbc2.optional.MysqlDataSource;
  
public class ConnectionDemo {
  
    public static void main(String[] args) throws SQLException, ClassNotFoundException {
        System.out.println("使用连接池................................");
        for (int i = 0; i < 20; i++) {
            long beginTime = System.currentTimeMillis();
            Connection conn = ConnectionManager.getInstance().getConnection();
            try {
                PreparedStatement pstmt = conn.prepareStatement("select * from T_TERMINAL");
                ResultSet rs = pstmt.executeQuery();
                while (rs.next()) {
                     // do nothing...
                }
            } catch (SQLException e) {
                e.printStackTrace();
            } finally {
                try {
                    conn.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
  
            long endTime = System.currentTimeMillis();
            System.out.println("第" + (i + 1) + "次执行花费时间为:" + (endTime - beginTime));
        }
        Connection con = null;// 创建一个数据库连接
        System.out.println("不使用连接池................................");
        for (int i = 0; i < 20; i++) {
            long beginTime = System.currentTimeMillis();
            //oracle
            Class.forName("oracle.jdbc.driver.OracleDriver");// 加载Oracle驱动程序
            String url = "jdbc:oracle:thin:@192.168.127.156:1521:ORCL";
            String user = "coll_platform";
            String password = "coll_platform";
            con = DriverManager.getConnection(url, user, password);// 获取连接


            // mysql
            // MysqlDataSource mds = new MysqlDataSource();
            // mds.setURL("jdbc:mysql://localhost:3306/zww");
            // mds.setUser("root");
            // mds.setPassword("123456");
            // Connection conn = mds.getConnection();
            try {
                PreparedStatement pstmt = con.prepareStatement("select * from T_TERMINAL");
                ResultSet rs = pstmt.executeQuery();
                while (rs.next()) {
                                    // do nothing...
                }
            } catch (SQLException e) {
                e.printStackTrace();
            } finally {
                try {
                    con.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
            long endTime = System.currentTimeMillis();
            System.out.println("第" + (i + 1) + "次执行花费时间为:"
                                + (endTime - beginTime));
        }
  
    }
}

执行结果

flawless